E F F E C T O F W E I G H T GAIN AND W E I G H T LOSS ON C E R T A I N
B ODY AND B L O O D C O N S T I T U E N T S O F R A T S

By
SALAH-ELDIN MAHMOUD LOUTFI

A THESIS
Submitted to the School of Graduate Studies of Michigan
State College of A griculture and Applied Science
in p a rtia l fulfillm ent of the requirem ents
for the degree of

DOCTOR OF PHILOSOPHY

D epartm ent of Food Technology

E F F E C T O F W E I G H T GAIN AND W E I G H T LOSS ON C E R T A I N
B O D Y AND B L O O D C O N S T I T U E N T S O F RATS

By
V

Salah-Eldin Mahmoud Loutfi

AN ABSTRACT
Submitted to the School of Graduate Studies of Michigan
State College of A griculture and Applied Science
in p artial fulfillm ent of the requirem ents
for the degree of

DOCTOR OF PHILOSOPHY

D epartm ent of Food Technology

Year 1953

Approved

SALAH-ELDIN MAHMOUD LOUTFI

The

influen ce of diets of different com position

and b lo o d c o n stitu e n ts and on the rate of
of r a t s

ABSTRACT

on c ertain bod}

weight gain and weight loss

w as stu d ie d .
D u rin g the gaining period two diets were fed ad libitum to

two g r o u p s
dient, w a s

of r a t s .

One diet, containing corn as the main in g re ­

u sed in an attem pt to produce obesity; the other diet,

con tain in g w h e a t and m ilk solids as the main ingredients, was used
as the

c o n tro l' d ie t.
T h e c o rn d ie t used failed to produce obesity in ra ts , if obesit

is i n t e r p r e t e d as ex cess body weight, but the ra ts on the corn diet
had a s ig n if ic a n tly higher fat content than those on the control wheat
diet.

T h e p ro te in , m oisture, and ash content of m ature ra t c a r ­

casses

w e re

s im i la r for anim als on both diets.

T h e co m po sition of the diet and age were found to affect the
blood c h o l e s t e r o l values.
serum

C holesterol concentration in the blood

i n c r e a s e d w ith the age of the ra ts .

Blood potassium values

were a f f e c te d by the type of diet, while blood pyruvic acid concen­
tra tio n s

w e re independent of age and diet.

A relationship was found

betw een body f a t content and the values fo r blood cholesterol, blood
pyruvic

acid , and blood potassium .

z
SALAH-ELDIN MAHMOUD LOUTFI

ABSTRACT

At the end of the gain-in-w eight period the corn-fed rats
were p a ire d according to weight, and divided into two groups.

One

group was fed a diet which was high in carbohydrate, and the other
group was fed a diet which was low in carbohydrate; the ra ts on
both diets w ere re s tric te d to 1Z calories per day.

No difference

was observed between the effects of the high-carbohydrate and the
low -carbohydrate re s tric te d diets on the rate of weight loss of rats
or on the body and blood constituents that were studied.
The blood cholesterol content of the rats on the re s tric te d
diets was low er and the blood potassium content higher than that ob­
tained for the rats on a control wheat diet.
values w ere sim ilar for all diets.

The blood pyruvic acid

ACKNOWLEDGMENTS

The author wishes to express his sincere thanks to Dr. C. L.
Bedford, Chairm an of the Guidance Committee, for his guidance and
k

help throughout the study, and to D r. W. D. B rew er and Dr. D. C.
Cederquist, under whose constant supervision and unfailing in te re s t
this investigation was undertaken.
He is greatly indebted also to Dr. M. A. Ohlson, the head of
the D epartm ent of Foods and N utrition, fo r her perm ission to carry
on the study and to use the m a te ria ls and facilities of the d e p a rt­
ment.
The in v estig ato r extends his sin cere thanks to M rs. H. C. Amen
and M iss M. M ills for determ ining the blood cholesterol and blood
pyruvic acid values.
The w rite r deeply app reciates the perm issio n of Dr. E. J.
Benne for the use of the facilities of the A griculture Chem istry Lab­
oratory, and to Dr. W. D. Baten for his aid in the sta tistic a l analy­
sis.

I

TABLE O F CONTENTS

Page
INTRODUCTION...................................................................................................

1

REVIEW OF LITERATURE

.........................................................................

5

...................................................................................................

5

Body Weight

Body Composition. . . .

6

F acto rs Affecting W e ig h t'L o s s ...........................................................

10

Blood Constituents

......................................................................................

13

................................................................................................

13

P o t a s s i u m ...................................................................................................

17

Pyruvic acid

20

C holesterol

............................ •...............................................................

EXPERIMENTAL PRO CED URES................
Experim ental Plan

25

...................................................................................

25

P erio d of weight g a i n ........................................................................

25

.........................................................................

25

............................................................................

27

...............................................................................

28

Experim ental M e th o d s ...............................................................................

29

P erio d of weight loss
Chemical analysis
Experim ental diets

Drawing the blood s a m p l e ..............................................................

.

29

iv
Page
P re p a ra tio n of sample fo r body a n a l y s i s .............................

29

M oisture d e te r m in a tio n ......................................................................

30

Ash determ ination

30

..........................................

P ro tein d e te r m in a tio n .........................................................................

31

F a t d e te r m in a tio n ....................................................

31

Blood p o t a s s i u m ......................................................................................

31

Blood c h o l e s t e r o l ...................................................................................

32

Blood pyruvic a c i d ................................................................................

34

.........................................................................

37

P erio d of Weight Gain

............................................................................

37

Body composition

............................................................................

43

...............................................................................

54

............................................................................

67

......................................................................................

67

Weight l o s s ................................................................................................

72

Body c o m p o s itio n ...................................................................................

77

Blood constituents

...............................................................................

84

SUMMARY AND CONCBUSION..................................................................

99

DATA AND DISCUSSION

Blood constituents
P erio d of Weight Doss
Control anim als

LITERATURE CITED
APPENDIX

.

......................................................................................

103

.............................................................................................................

114

LIST OF TABLES

Table

Page

1.

Composition of d i e t s ..........................................................................

26

2.

Average weight, gain in weight, food and
caloric, consumption of rats during the
period of weight gain .....................................................................'

38

Average weight gain of rats on corn and wheat
diet d u rin g ’pdriod of weight gain
........................................

42

The average' body composition of ra ts during the
period of weight gain .....................................................................

44

The average body composition of corn and wheat
fed ra ts (period of weight gain) and analysis of
variance ....................................

46

C orrelation coefficient of body weight, body
constituents, and tim e on diet of rats during
the period of weight gain ............................................................

48

Blood cholesterol, pyruvic acid, and potassium
of ra ts during the period of weight g a i n ..........................

57

The average blood constituents of ra ts during
the period of weight gain ...........................................................

59

C orrelation coefficient of blood constituents and
time on diet of ra ts during the period of weight
gain .............................................................................................................

64

Average changes in weight of rats during the
period of weight loss .....................................................................

70

Changes in weight of rats during period of weight
loss .............................................................................................................

73

3.

4.

5.

6.

7.

8.

9.

10.

11.

vi
Table
12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

Page
The average body composition of ra ts during
the period of weight loss
.............................................

74

Average body constituents of rats during the
period of weight loss ...........................................................................

76

C orrelation coefficients of some body constituents
.................................................
during the period of weight loss

82

C holesterol, pyruvic acid, and potassium content
of blood of ra ts during the period of weight loss . . .

89

A nalysis of variance of blood constituents of
rats during the period of weight loss ..................................

91

C orrelation coefficient of certain blood constituents
and time of experim ent for rats on low calorie
d i e t s .............................................................................................................

95

Data for rats fed wheat diet during the period
of weight gain ..........................................................................................

115

Data for ra ts fed corn diet during the period
of weight gain ..........................................................................................

117

Data for rats fed wheat diet during the period
of weight loss ..........................................................................................

119

Data for rats fed low carbohydrate diet during
the period of weight loss
................................................................

121

Data for rats fed the high carbohydrate diet
during period of weight lo ss .........................................................

123

Rats that died or, were killed and the apparent
cause

125

LIST O F FIGURES

F igure

Page

1.

Standard curve for potassium determ ination

................

33

2.

Graph showing rate of growth of rats fed
corn and wheat diets com pared with rate of
growth reported by K i n g ...............................................................

40

R egression of weight gain on time of diet
during period of weight gain .....................................................

41

R egression of m oisture content on time during
the p eriod of weight gain ...........................................................

49

R egression of body m oisture content on bodyfat
during period of weight gain .....................................................

50

R egression of protein content on time during
period of weight gain ....................................................................

51

R egression of ash on time during period of
weight gain ............................................................................................

53

R egression of body fat content on tim e during
period of weight gain ....................................................................

55

R egression of body weight on fat content
during period of weight gain ....................................................

56

R egression of cholesterol on time during period
of weight gain . ...................................................................................

61

11.

R egression of cholesterol on body f a t ..................................

62

12.

R egression of potassium on time during period
of weight gain ......................................................................................

65

3.

4.

5.

6.

7.

8.

9.

10.

v iii
F igure
13.

14.

15.

Page
R egression of potassium on fat content during
period of weight gain ............................................................................

66

R egression of pyruvic acid on time during period
of weight gain
..................................................

68

R egression of body fat on pyruvic acid during
period of weight gain

69

w ->

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

R egression of weight lb-ss on time during period
of weight loss ............. ’. ...........................................................................

78

R egression of fat on time during period of
weight loss ............................................................................................

80

R egression of weight loss on fat content during
period of weight loss . ...............................................................

81

R egression of m oisture on time during reducing
p e r i o d ...................................................................................................... ...

83

R egression of protein on tim e during period of
weight loss
...................................................................................

85

P ro tein changes (fat-free basis) during period
of weight loss .....................................................................................

86

R egression of ash on time during period of
weight loss
....................... .................................................

87

R egression of cholesterol on time during period
of weight lo ss .....................................................................................

88

R egression of pyruvic acid on time during period
of weight lo ss ......................................................................................

93

R egression of potassium on time during period
of weight loss ......................................................................................

96

INTRODUCTION

Obesity, which was once considered a desirable phenomenon,
has become a nutritional and health problem .

Dublin and Lotka

(29) stated* t h a t t h e penalty of overweight is one-fourth to th ree fourths excess in m o rta lity ."

F isk (36) pointed out that 50 pounds

overweight at age forty-five was as dangerous to life as valvular
h e a rt disease.

In addition to the m o rtality risk , obese persons w ere

found to be m o re susceptible to infectious diseases, a rte ria l h yper­
tension, diabetes, gallstones, and w ere poorer surgical risk s than
individuals of ideal weight (10).
S ebrell (93) rep o rted that 25 p e r cent of the adults in the
United States w ere overweight.

The hazardous effect of obesity and

its w idespread distribution has attracted the attention of many w orkers
who have attem pted to discover why human beings become obese.

At

f ir s t it was believed that obese persons had lower b asal m etabolic
ra te s than nonobese individuals, but fu rth er studies dem onstrated that
this was not tru e (13, 102).

As the functions of the endocrine glands

becam e understood, it seem ed to many leading authorities in the
field that hypofunction of the pituitary, thyroid, or the gonads offered
an adequate explanation of obesity.

However, fu rth er studies (reviewed

2
by Newburgh, 77) have shown that this is not the case.

Evidence

from the lite ra tu re rep o rted by Newburgh (77) showed also that the
th eo ries of specific dynamic action of foods, luxusconsumption and
hypoglycemia cannot explain the cause of obesity.
The theory that obesity is the re su lt of an intake of energy
that exceeds the output was substantiated by Newburgh and Johnston
(75) and has been accepted alm ost universally; yet there a re cases
of obesity not readily explained by this theory (6, 20, 50).

D iffer­

ences have been rep o rted in the m etabolism of carbohydrate and fat
of obese subjects from those of n orm al subjects (112).

Lack of

knowledge about the causes of this im p ro p er balance between intake
and output in obes.e persons has handicapped the trea tm en t of obesity.
However, it seem ed clear th at the treatm en t m ust consist of either
reducing the food intake or causing the body to burn m ore calo ries.
Since re stric tio n of caloric intake was found to be m ore p ractical
than increasing the caloric output of the body, sev eral low -caloric
diets have been used for the treatm en t of obesity.

The work of

Hagedorn, Holten, and Johansen (43) postulated, that obesity a ris e s
from an abnorm ally in creased tran sform atio n of carbohydrates into
fat, due to qualitative anomaly of m etabolism .

On this b asis, Hanssen

(44) used a high-fat and low -carbohydrate diet for reducing weight.

3
T here is a conflict between in vestigators about the advantage of the
use of such a diet over the re g u la r low -fat re s tric te d diet.

In a

study of the physiology of women during weight reduction conducted
by the departm ent of Foods and N utrition at Michigan State College,
C ederquist _et al. (18) rep o rted that a low -carbohydrate reducing
diet, patterned in p a r t afte r the diet published by Pennington (81),
gave m o re satisfacto ry re su lts than had been obtained previously
with a low -fat reducing diet.

Subjects lo st m ore weight without suf­

fering from hunger and th e re was no flabbiness or looseness of skin;
these observations w ere in agreem ent with the work of Hans sen (44).
Since the work of both Hanssen (44) and C ederquist et al. (18)
was c a rrie d out on human subjects who may have had different
m otives for weight reduction or who may have been under certain
em otional s tre s s e s , it was felt that a controlled experim ent was
needed in which these variab les could be elim inated.

A study, th e re ­

fore, was planned in which ra ts w ere used as the experim ental ani­
m a ls.

The ra te of weight gain and weight loss, and the composition

of certain body and blood constituents of ra ts and high- or lowcarbohydrate diets w ere studied.
Since the m etabolism of cholesterol has been reported to be
allied closely with lipid m etabolism , and since pyruvic acid and

4
potassium have been shown to have ro les in fat and carbohydrate
m e tab o lism ,.. s.tudie's <Jof the blood cholesterol, blood pyruvic acid, and
blood potassium during the periods of. weight gain and weight loss
w ere m ade.

REVIEW O F L I T E R A T U R E

It is well known that the chem ical composition of an animal
body, as well as its weight, is not fixed and constant, but changes
throughout life from conception until death.

Body Weight

The changes in body weight of different anim als have been
studied by many investigators.

Donaldson (28), F e rry (34), and King

(60) studied changes in body weights of ra ts during the growth period.
These w orkers found that after the age of 120 days, the in c re a se in
body weight was relatively sm all.

Their data showed that the in ­

crease in body weight did not cease entirely when the r a t reached
m atu rity, but that it usually continued as long as the anim als were
in healthy condition.

They also rep o rted that differences in body

weight between m ales and fem ales becam e distinct at the age of
60 days.
King (60) suggested that the weight in c re a se in adult ra ts is
not tru e growth, but chiefly the accum ulation of adipose tissue, and
concluded that the body weight of the r a t a t any given age depended
to a considerable extent on the c h arac ter of the food.

This has

6
been pointed out also by Hatai (47) and C arlson and Hoelzel (17).
O thers (90, 23) d isagree, and rep o rted that as long as the diet is
adequate, the in c re a se in weight of the body tends to be of the same
composition, despite the differences in the diet.

Body Composition

During the active growing period, the percentage of body fat
generally in c re a se s, while the percentage of body w ater decreases.
It has been suggested (72) that if the fa t-fre e composition is con­
sidered, a point is reached when the concentrations of w ater, protein,
and ash become m ore or less stationary, and afte r which no fu rth er
appreciable changes take place.

Moulton (72) described this as the

state of chem ical m atu rity which is reached after 50 days in the rat.
Every m a tu re anim al body contains a certain amount of energy
stored as fat, the amount of which v a rie s from species to species.
C ertain individuals among some species w ere found to sto re m ore
fat than others.

This is believed to be due to an upset in the m e ch ­

anism which controls the energy intake with the energy output (55).
As this exces-s deposition of fat is desirable for m eat anim als, many
w orkers have striv en to develop such deposition of fat in anim als.
*

1*

s

M urray (73)' has rep o rted 50 p e r cent body fat for sheep and pigs.

1

There have been no re p o rts in the available lite ra tu re of other m a m ­
m als, with the exception of humans (101), that have contained such a
high percentage of fat.

Beef cattle, selectively b red for th e ir ability

to sto re fat, attained a m axim um p e r cent of 37 (74).

Spray (101)

rep o rted that the m atu re fem ale r a t at the age of 200 days contained
23.7 p e r cent fat; this p e r cent of body fat was higher than that for
the m ale r a t of s im ila r age.

She suggested this figure as the upper

lim it fo r the species since the percentage d ecreased in the older an i­
m als.

Values of 13.4 and 12.8 p e r cent for m ale ra ts at 246 and

321 days _of agey respectively (101), are s im ila r to the figure 13.4
p e r cent reported by Chanutin (21) fo r adult anim als.

Hatai (47)

found only 5.7 p er cent fat in r a ts that w ere 294 days old.

Donaldson

(28) and Deuel et al. (24) also rep o rted that fem ale ra ts contained
m ore fat p er 100 gram s body weight than m ale r a ts .

They rep o rte d

18.1 p e r cent fo r m ales and 20.1 p e r cent fo r fem ales at the age of
84 days.
Smith (96) obtained ra ts having 50 to 60 p er cent fat by injury
of the tuber cinereum of the hypothalamus.

This method has been

used by many investigators to obtain obesity in ra ts and other an i­
m als (87, 49).

Obesity obtained by such a method is accompanied

by endocrine disturbances.

T herefore, this does not re p re se n t a

tru e picture of the obesity which re su lts when energy intake exceeds
energy output 3 ^,the in tact animal.
Spray (101) found that the percentage of w ater in the body
depended to a large extent on the percentage of fat.

There was a

corresponding, though not equal, d ecrea se in w ater when there was
an in c re a se in fat.

She found that the average content of w ater was

56 per cent at the age of 120 days, with an in c re a se to 60 p er cent
at the age of 370 days.

Hatai (47) rep o rte d a percentage of 65.3

of w ater in the body of the m atu re ra t.

He concluded that the p e r ­

centage of w ater and body weight and age were not related,

Deuel

et a l. (24) reported, that the average per cent of w ater in ra ts studied
in his experim ent was 58.2 fo r m a les and 56.8 fo r fem ales.
Spray (101), Donaldson (28), Chanutin (21), and Deuel et al.
(24) showed that changes in protein values w ere re cip ro cal to those
for w ater.

This was dem onstrated m ost clearly in the r a t by Spr.ay

when the data for w ater and protein w ere calculated on a fa t-fre e
b asis.

Spray (101) rep orted that r a t c a rc a sse s contained 16.8 p er

cent protein, a value which was sim ila r to that reported by Hatai
(47).

Chanutin (21) rep orted values that w ere slightly lower, but the

curve was a sim ila r one and a constant percentage was reached at
an age of approxim ately 100 days.

Deuel £t al. (24) found 17.3 p er

9
cent protein In the m ales and 16.2 p er cent fo r the fem ales.

All

w orkers agreed that the per cent of protein rem ained relatively
constant throughout the life of the m a tu re ra t.
The ash content of the body of ra ts studied by Chanutin (21)
reached the m axim um at the twentieth day of age, afte r which th e re
was a gradual but m arked decrease (21).

Hatai (47) rep o rted that

the m a tu re r a t contained 3.7 p er cent ash, which was s im ila r to the
resu lts obtained by Chanutin (21).

Deuel et al. (24) found that the

fem ales had a higher percentage of ash than the m ales:

3.26 and

2.95 respectively.
The effect of different diets on the weights and body compo­
sition of m ale and fem ale ra ts has been studied by many in vestig ators
(47, 17, 90).

Hutchinson (53) rep o rted that the fat content of anim als

cannot be predicted from th e ir live weights or ra te s of in c re a se in
live weights, because the fat content of the body may be influenced con­
siderably by the ration that is fed.

Hutchinson and B aker (54) made

a detailed investigation of the effect of various diets in the pro p o r­
tions of protein, fat, and dry m a tte r in the bodies of dom estic ra b ­
b its,

They showed that although the growth curves were sim ilar

whether the anim als w ere re a re d on weeds or on potatoes and hay,
the bodies of the potato-fed group contained much m ore fat than those

of the other group.

Wynn and Haldi (113) Reported that a diet con­

taining 50 p e r cent fat induced a d ecrease in the w ater and protein
content, and a definite in c re a se in the amount of fat in the skin and
body of the' albino ra t; these changes o ccurred within seven days.
Scheer et al. (90), Deuel et al. (24),

and Bachmaim et al.

ported that the fat content of the body of the

(4) r e ­

ra t was not closely r e ­

lated to the fat content of the diet.

F a c to rs Affecting Weight Loss

The loss of excess weight can be accom plished only by the
burning of the excess fat deposits.

The only universally accepted

method to b u m this excess fat and thereby reduce the weight of the
obese is to r e s tr ic t the caloric intake.

Evans and Strang (31) r e ­

ported that the burning of excess fat is in d irect proportion to the
difference between the energy intake and the energy output.

These

authors used diets re s tric te d to 600 calo ries per day but stre s s e d
that in lim iting the diet there should be an adequate intake of p ro ­
tein, m in erals, and vitam ins, enough carbohydrate to avoid acidosis,
and no fat other than that which could not be separated from the
protein ration.

F a ilu re of some individuals to lose weight on such

a severe regim e has been rep o rted in the lite ra tu re (75).

No

11
satisfac to ry explanation fo r such cases has been given.

Hagedorn,

Holten, and Johansen (43) suggested that obesity a r is e s from a b n o r­
m ally in c re a se d tran sfo rm atio n of carbohydrate into fat, due to a
qualitative anomaly of m etabolism .

This idea was used as a b asis

for the tre a tm e n t of obesity; the percentage of carbohydrate in the
diet was reduced to preven t a surplus of carbohydrates being de*
'
posited a s .f a t. ' 'This tre a tm e n t re c e iv e s added justification from the
fact th at many p ersons with obesity becom e diabetic.

The lo w -carb o ­

hydrate diets have been subjected to both clinical and experim ental
investigations.

Benedict and M ilner (8) com pared diets of equal

calo ric value and dem onstrated that diets high in fat caused a m o re
im m ediate loss in the weight of the subject than diets that w ere high
in carboh ydrates.

Lyon and Dunlop (65) rep o rte d that on s h o rt-te rm

experim ents,, the loss of weight on diets containing 1,000 calo ries
appeared to b e in v ersely proportional to the carbohydrate content
of the food.

H anssen (44) showed that his patients lo st m o re weight

on a high-fat diet than those on a high-carbohydrate diet.

Anderson

(2) studied the influence of the com position of subm aintenance diets
on the loss of weight of obese patients.

He concluded that high-fat

diets apparently led to a m o re rap id lo ss of weight than highcarbohydrate diets.

F ro m com parison of analytical figures, however,

12
he discovered that in addition to the difference in the amounts of
carbohydrates and fats, the diets also differed in salt content.

The

chloride content of the high-carbohydrate diet was found to be 3.99
gram p e r cent, while that of the high-fat diet was 1.33 gram p e r
cent.

He m ade a com parison of high-fat and high -carbo hyd rate diets

of equal s a lt content.

R esults indicated that the excessiv e w ater and

salt rete n tio n on the high-carbohydrate diet was due to the high con­
tent of sa lt r a th e r than the high content of carbohydrate.

On is o ­

caloric diets of equally low s a lt content, w hether high in fat o r high
in carbohydrate, A nderson (2) found that weight lo sse s w ere identical.
Scheer, Codie, and Deuel (89) found that when the intake of
fem ale ra ts was re s tric te d to 12 calo ries p e r day, the anim als lo st
30 to 40 p e r cent of th e ir weight in eight weeks.

The g re a te s t weight

loss o ccu rred in anim als fed the diets containing 5 or 10 p e r cent fat
and the low est lo ss in ra ts that w ere fed 20 to 40 p e r cent fat.
The question of w ater balance a r is e s whenever reduction of
weight is attem pted.

Newburgh and Johnston (75) and Newburgh and

L ashm et (76) have re p o rte d the tendency of obese patients on a low
calo ric diet to re ta in w ater which prevented loss of weight.

B a rte ls

and Blum (7) found th at a disturbance in w ater balance o ccurred
during attem pts at weight reduction by low calo ric diets.

Scheer

13
and co -w o rk ers (89) rep o rte d th at caloric re s tric tio n re su lte d in
relativ ely high w ater content in the body.

Evans and Strang (31)

felt that this w ater retentio n was due to the spontaneous a lte ra tio n
in the capacity of fa t to sto re w ater.

Newburgh (77) rep o rte d that

in the living organism , pro tein is asso ciated with th ree tim es its
weight of w ater, and fat with one-tenth its weight.

When fat is

burned in the body, w ater is released ; and thus the per cent of body
w ater is in c re a se d ,

Evans and Strang (31) studied the nitrogen b a l­

ance, the oxygen consumption, and the carbon dioxide output of obese
patients.

They rep o rte d that fat was the only component that was

burned in the body when the diet was adequate in protein and m in e r­
a ls but r e s tr ic te d in calo ries.

The work of Scheer and co-w orkers

(89) on ra ts substantiated this observation.

They rep o rte d that a

c alo ric r e s tric tio n resu lted in a relativ ely high w ater content with a
slight in c re a s e in ash and p rotein and a great reduction in fat.

Blood Constituents

C h o le stero l.

C holesterol, one of the anim al ste ro ls, is an

e sse n tia l constituent of all cells and fluids of the body (10).

Chol­

e s te ro l contains an -alcohol group and ex ists in the blood in the free
state and as e s te r s of fatty acid s.

Among many other physiological

functions, ch o lestero l ap p ears to act as a fat-m obilizing agen t (109,
22, 41, 10, 84).

Some in v e stig ato rs believe that the ch o lestero l con­

centration in blood is fairly constant (41, 78, 109, 15, 61), and any
change would be a re s u lt of a m etabolis disturbance in the body.
A th e ro sc le ro sis, one of the d iseases that was found to in c re a s e the
concentration of blood cholestero l, was found to be common in obese
individuals.

This suggested that there m ight be a relatio nship b e ­

tween ch o lestero l m etabolism and obesity.

Other in v estig ato rs (16,

92, 99, 109, 41, 67) rep o rted varying blood cholesterol concentrations
fo r n o rm al subjects.

This v ariatio n may be accounted fo r by differ-

ences in the experim ental conditions, pathology of the subjects, and
to a g re a te r extent by the lim itations of the m ethods used fo r analy­
sis.

V ariations in cholesterol values w ere obtained also for ra ts .

M onnier and co -w o rk ers (71) rep o rte d a blood ch o lestero l average
of 80 m illig ram s p e r 100 m illilite rs , 70 p er cent of which was
e sterized .

T readw ell and E ckstein (107) repo rted an av e ra g e of 68

m illig ra m s p e r 100 m illilite rs .
Many facto rs--am o n g them diet, obesity, sex, age, and state
of n u tritio n --h av e been re p o rte d to influence the concentration of
blood cho lestero l.

Rony and Levy (88) found that the blood lipid

values of humans w ere affected by the ingestion of food-fat, and

15
concluded that som e individuals had g re a te r ^tolerance for fat than
o th ers.

Bloor (12) re p o rte d th at a high-fat diet produced an in c re a s e

in the blood ch o lestero l in the dog and in the rab b it.

The difference

was not app reciab le in dogs, but was m ark ed in the rabbit.

Luden

(64) found that diets affected the blood ch o lestero l in humans.

Nhavi

and Patw ardhan (78) re p o rte d th at cholesterol values of humans ap ­
peared to be independent of the fat intake.

Gough (41) found no c o r­

relatio n between the ch o lestero l intake and its concentration in the
blood.

T u rn er and co -w o rk ers (109), B ru g er and Somach (16), and

Schube (92) rep o rte d th a t the blood cholesterol values tended to be
constant re g a rd le ss of the food intake.

Steiner and Domanski (104)

rep o rted that when ch o lestero l was m ixed with lecithin in the diet,
a notable r is e in the concentration of blood ch o lestero l occurred,
while the ingestion of ch o lestero l alone o r m ixed with fat had no ef­
fect.

Keys et al. (58) rep o rte d that although the cholestero l intake

had no effect on the concentration of blood ch olestero l, the blood
cho lesterol was low ered if the diet was fre e from cholesterol.

In

ra ts , Treadw ell and E ckstein (107) concluded that diet had no effect
on the blood ch o lestero l.
T here a re conflicting re p o rts concerning the effect of obesity
on blood ch o lestero l values.

E llio tt and Nuzum (30) found that

16
cho lesterol values frequently w ere higher among underw eight than
among obese p erso n s.

Denis (26) rep o rte d that plasm a ch o lestero l

was elevated in cases of obesity.

On the other hand, se v e ra l studies

have been re p o rte d in the lite ra tu re in which the blood ch o lestero ls
of obese subjects w ere found to be n o rm al (52, 15, 82).

B lotner

(11) found a difference in the blood ch olesterol levels between n o rm al
and obese individuals when a te s t m eal, high in fat, was ingested.
H igher values of blood ch o lestero l have been rep o rte d for
fem ales than m a le s, and low er values fo r children than adults (61).
However, Rafsky and Newman (86), P e te r s and Man (82), and Keys
and his co -w o rk ers (58) rep o rte d that th e re was no significant dif­
feren ce between the values for m en and those for women.

Keys et

al. (58) re p o rte d higher values fo r ch olesterol in p ersons over th irty
y ears of age than in younger p erso n s.

The in c re a s e was found to

be approxim ately 2.2 m illig ra m s of to tal cho lesterol p e r 100 m illi­
lite r s of seru m p e r y e a r of age over th irty .

K irk et al. (59), on

the o th er hand, found no significant difference in blood ch o lestero l
concentrations between h is subjects who ranged from 21 y e a rs of
age to 91.

In ra ts , T readw ell and E ckstein (107) found no d iffer­

ences between sexes.

M onnier and co-w orkers (71) rep o rted that the

blood ch o lestero l of m a tu re ra ts was s im ila r to that of young ra ts .

17
Man and Gildea (66) studied m alnourished patients and found
that the ch o lestero l content of blood v aried with the state of nutrition.
The bloods of em aciated patients had low er ch o lestero l values than
those of n o rm al persons; im provem ent of the n u tritio n al condition
resu lted in a r i s e in the ch o lestero l concentration.

This also was

observed by Bose and his co -w o rk ers (14), G ardner and Landen (38),
and Shope (95), who rep o rte d low ch o lestero l values in starv ed p e r ­
sons.

P oind ex ter and B ru g er (83) found that the ch o lestero l content

of the plasm a was not a lte re d during periods of weight reduction on
re s tric te d diets.

However, they observed that in some patients, low

calo ric diets caused a definite in c re a s e in plasm a ch o lestero l for
se v e ra l weeks.

Walker and his co -w o rk er (111) observed the sam e

in c re a s e in p lasm a ch olesterol in obese individuals who underwent
rapid weight reduction by rig id calo ric re s tric tio n .

P oindexter et

,<r
a l . (83) explained this in c re a s e in the plasm a ch o lestero l as being
the effect of starvation.

Amen (1) re p o rte d a d e c re a se in the blood

ch o lestero l concentration during weight reduction which was followed
by an in c re a se .

This was explained as the re s u lt of adjustm ent to

the r e s tr ic te d calo ric intake.

P o ta s s iu m .

P o tassiu m is quantitatively the m o st prom inent

cation of in tra c e llu la r w ater.

A num ber of observations, reviewed

18
by Ferm (33), have indicated the im portance of potassium in m uscle
physiology.

A relationship of potassium to carbohydrate m etabolism

has been indicated by sev eral in v e stig ato rs.

P u lv er and V erzar (85)

rep o rte d that the uptake of glucose by the y e a st cell is accom panied
by a sim ultaneous uptake of potassium .

Othrfr in v estig ato rs have

shown that the anaerobic ferm entation of glucose by anim al tissu e s
was m arkedly g re a te r in a m edium containing sodium and potassium
than in a m edium containing sodium alone (33, 63).

These re s u lts

have shown that potassium is able to activate the enzym atic b re a k ­
down of glucose, but the question has been left open as to how this
activation takes place.

P ulver and V erzar (85) assum ed that the

inw ard diffusion of potassium was connected with the phosphorylation
of glucose a s the in itia l reactio n leading to the form ation of a poly­
sacch arid e.

H astings and Buchanan (46) found that optimum glyco-

genesis in liv e r slic es req u ired an a rtific ia l m edium containing
potassium , m agnesium , and sodium.

Fenn (32) observed that the

ra tio of potassium to glycogen in liv er was constant, no m a tte r what
concentration of glycogen was produced in the liv e r.

G ard n er and

co -w o rk ers (39) stated that potassium has a dual effect on carbohy­
d rate m etabolism .

One effect involves the overproduction of adrenal

c o rtic a l horm ones; the second is the effect on tissu e glycogenesis.

19
^

p’J

F a c to rs that affect the p otassium concentration in the blood
a re :
Age:

B enetato and C uird aru i (9) found that the blood serum

of r a ts , eight to nine m onths old, contained an average of 31.5
m illig ram s of potassium p e r 100 m illilite r s .

This seem ed to in c re a s e

with age and reached an av erag e of 39-2 m illig ra m s of potassium p er
100 m illilite r s at the age of two y e a rs .
Diet:

The d ietary intake of potassium was found to have an

effect on the amount of potassium in the blood plasm a and o th e r t i s ­
sues (70, 57).

A high p o tassiu m ra tio n caused an in c re a s e of the

potassium concentration in r a ts and dogs.

G ard ner and co -w o rk ers

(39) produced p o tassiu m -deficient r a ts by feeding them a diet con­
taining 0.07 m illim o ls of p o tassiu m p e r 100 gram s of diet.

Dienst

(27) re p o rte d that sodium displaced potassium in the o rgan ism 'and
had a w a ter-retain in g action.
a flushing action.

P o tassiu m drove out sodium and had

W hether one o r the o th e r ion dominated in its

action depended upon the p rop o rtio n between the two.
am ount was ■unimportant.

The absolute

Keizo (57) rep o rted that on a carbohydrate-

poor diet, the potassium -calciu m quotient in the blood was higher
than on a ca rb o h y d ra te -ric h diet.

The r is e in the quotient m ight be

caused by a m ovem ent of calcium into the tissu e s and of potassium

from the tissu e s to the blood.

V e rz a r and Somogyi (110) showed

that the intake of glucose, galactose, o r fru cto se caused a sudden
in c re a s e of blood potassium .

The peak of the potassium values was

reached only when the su g ar concentration in the plasm a had begun
to d e c re a se .
B asal M etabolism:

L arso n and B rew er (62) found that the

m etabolic ra te affected the potassium content of the blood serum .
They suggested th at the lowering of serum potassium by anesthetics
was a re s u lt of low ered m etabolic ra te .
Fasting:

Mellinghoff (68) rep o rte d that the potassium content

of the seru m during fasting in c re a se d slightly at the beginning of
the fasting, then fell and rem ained for months n ear the low er liiriit
of n orm al values.

Keizo (57) reported, a s im ila r r is e of potassium

blood values during fasting and suggested that this resu lted fro m a
m ovem ent of potassium fro m the tissu e s to the blood.
P yruvic acid .

The p ro cess by which sugar is converted into

fatty acid s is not well understood.

Starling (103) suggested that

since carbohydrate m etabolism , both in anim al and alcoholic ferm e n ­
tation, p asses through stages of th re e carbon compounds, pyruvic
acid o r lactic acid, it is possible that one or the o th er of th ese comt-t*

pounds form the sta rtin g point from which fat is synthesized.

21
Aldehydes p o sse ss the p ro p erty of condensing to form long
chain compounds containing secondary alcoholic groups which may
lose w ater with the production of double bonds.

V arious schem es,

based on this property, to explain the form ation of fatty acids from
carbohydrates have been postulated.

Starling (103) suggested that a

m olecule of acetaldehyde derived from pyruvic acid condenses with
a second m olecule of pyruvic acid with the production of an u n sat­
urated keto acid.
crotonic aldehyde.

The, lo ss of carbon dioxid# yields the unsaturated
The la tte r , by reduction, would yield butyric

aldehyde, which on oxidation would yield butyric acid.

H aarm ann

and Schroeder (42) studied the conversion of fat into sugar.

They

concluded that the probable in term ed iate step s a re butyric to crotonic
to b eta hydroxybutyric to aceto acetic to dihydroxybutyric to dihydroxycrotonic to diketobutyric to m ethylglyoxal to pyruvic o r lactic acid to
sugar.
Some of the fa c to rs that affect the pyruvic acid concentration
in the blood have been studied by various w orkers.

Friedem ann and

his co-w orkers (35) found that the ingestion of carbohydrates and
proteins ra is e d the concentration of pyruvic acid in the blood of
humans.

The ingestion of fat did not affect the pyruvic acid content

of the blood when la rg e quantities were ingested.

Smith (97) also

\

rep o rte d that glucose ingestion caused an in c re a s e in the blood
pyruvate concentration in hum ans,

Hatz (48) found that the pyruvic

acid concentration in the blood of ra ts was in c re a se d after the
intravenous o r subcutaneous ad m in istratio n of each of fourteen n a t­
u ra l amino acids.
S everal w orkers have studied the effect of vitam in deficiencies
on the pyruvic acid content of the blood.

Bargoni (5) rep o rte d that

the absence of Vitam in A in the diet caused an in c re a s e in the
pyruvic acid content of the blood of r a ts .

F riedm ann and his co­

w orkers (35) found that thiam ine deficiency in c re a se d the concentra­
tion of pyruvate in the blood of hum ans.

Goldsmith (40) found that a

thiam ine, riboflavin, or niacin deficiency in c re a se d the concentration
of pyruvate in the blood of humans.
The effect of various physiological and pathological d iso rd e rs
on the blood pyruvic acid has been studied.

Bargoni (5) rep o rte d

that tum ors in r a ts caused the pyruvic acid content of the blood to
in c re a s e .

Monge (69) found that lactic and pyruvic acid concentra­

tions in human blood significantly in c re a se d a t high altitudes.
was found to be due to anoxia. (35).

This

It was rep o rted by De Michele

and F ra n c is c is (25) that the in c re a s e in the blood pyruvic acid con­
cen tration of tuberculous patients was not rela ted to the clinical

asp ect of the d isease, but to the degree of re s p ira to ry insufficiency.
P alom ba and Budroni (80) found that anesthesia in c re a se d the pyruvic
acid concentration of the blood of humans and that the amount of
in c re a s e depended upon the type of anesthesia used.

They also ob­

serv ed an in c re a s e in the pyruvic acid concentration afte r various
operations and that the amount and duration of the in c re a se w ere
proportional to the severity and duration of the operation.

Stotz and

B essey (105) believed that this in c re a se may have been caused by
excitem ent and shock.

Taylor and McHenry (106) studied the py­

ruvic acid m etabolism of obese and n orm al subjects and repo rted
that no difference was found.

Stotz and B essey (105) rep o rted that

different degrees of fasting caused the blood pyruvic acid concen­
tratio n in pigeons to decrease.
The effect of age on the concentration of pyruvic acid has
been studied by W ortis and h is co-w orkers (114), who found no sig ­
nificant difference between the blood pyruvic acid values of

subjects

from seven to seventy years of age.
E x erc ise and excitem ent w ere rep o rted to have an effect on
the blood pyruvic acid concentration (105).

Goldsm ith (40) rep o rte d

th at the in c re a s e in the concentration of pyruvic acid in the blood of
humans was found to be dependent upon the degree of physical activity.

T here is little inform ation in the available lite ra tu re concern­
ing the blood pyruvic acid of r a ts .

B argoni (5) rep o rte d that he

found the concentration to be 13 m ic ro g ra m s p e r m illilite r of blood
in the n o rm al ra ts .

EXPERIMENTAL PROCEDURES

E xperim ental P la n

T hree-m o nth-old white fem ale r a ts w ere used as ex p e ri­
m ental anim als.

Upon a rriv a l, o n e-th ird of the ra ts , selected at

random, w ere assigned to Diet A, the com position of which is given
in Table 1, and designated as Group I.

The rem aining tw o-thirds

w ere assigned to Diet B (Table 1) and designated as Group II.

P erio d of weight gain.

During a period of twenty weeks the

two groups w ere fed the assigned diet and w ater ad libitum .
vidual daily food intake re c o rd s w ere obtained.

Indi­

Animals were

weighed each week on two consecutive days and the average of the
two weights was calculated.

A fter a period of six weeks, two ra ts

from each group w ere killed fo r an aly sis every week fo r four weeks.
F o r ten weeks th e re a fte r, two ra ts of each group w ere killed every
two weeks for analysis.

P erio d of weight lo s s .

During th is period, Group I was kept

on Diet A, fed and w atered ad libitum .

These ra ts served as con­

tro l anim als during the period of weight lo ss.

Rats of Group II w ere

26
T a b l e 1.

C o m p o s i t i o n of d i e t s .
Diet
D
HighCarbohydrate

A
Wheat

B
Corn

C
LowCarbohydrate

(gm)

(gm)

(gm)

(gm)

Whole wheat, ground

66

--

--

--

Whole m ilk solids

33

72

32

40

15

31

23

4

4

4

29

8

Ingredients

Sodium chloride

1

Whole yellow corn, ground
Casein

--

Yeast
Oil

--

--

Cod liv er oil

1

1

1

Wesson salts

3

3

3

Sucrose
Lettuce

5, twice
a week

Ground beef

5, twice
a week

--

--

21

-—

“—

——

•‘1

27
p aired according to weight, and one of each p air was given Diet C
(Table 1); this group of ra ts was designated as Il-a .

The o th er rat

of each p a ir was given Diet D (Table 1); these anim als w ere called
Group Il-b.
Each r a t of Group Il- a was given 2.5 gram s of Diet C daily,
and each ra t of Group Il-b was given th ree gram s p e r day of Diet
D.

Each diet provided 12 calo ries p e r day for each rat.

m als w ere given w ater ad libitum .

All ani­

Two anim als from each group

w ere killed weekly fo r seven weeks.

In the eighth week, five rats

from each group w ere killed for analysis and the experim ent was
term inated.

Exam ination of Table 18 (Appendix) shows the num bers

and weights of the ra ts in each group.
An autopsy was p erfo rm ed on each anim al that died o r showed
signs of illn e ss during the experim ent.
excluded from the experim ental re s u lts.

Data on these anim als w ere
The num ber of ra ts that

died from each group .gnd the suspected cause of death is tabulated
*

4

V r*

in Table 23 (Appendix) i-

Chem ical a n a ly sis.

Before each r a t was killed, it was a n e s­

thetized and a blood sam ple was obtained from the h eart f o r ch o les­
te ro l, pyruvic acid, and potassium content analyses.

The r a t then

28
was killed by a blow on the head and determ inations were made on
the c a rc a ss fo r m o istu re, fat, ash, and p rotein content.

E xperim ental diets.

The com position of the experim ental

d ie ts--D ie ts A, B, C, and D --is given in Table 1.

Diet A, the con­

tro l diet, whicb. is sim ila r to the one describ ed by Sherman (94),
was made up of ground whole wheat, whole m ilk solids, and sodium
chloride.

The ra ts w ere fed five g ram s of ground beef and five

gram s of lettu ce twice weekly.

The diet furnished 4.2 gram s of p r o ­

tein, 2.5 g ram s of fa t, and 13 gram s of carbohydrate p e r 100 c a l­
o rie s.

D iet B consisted of ground yellow corn, casein, yeast, oil,

cod liv e r oil, and W esson sa lts.

This diet had been used in e a r lie r

experim ents in the D epartm ent of Foods and N utrition at Michigan
State College, and it h-ad been observed that ra ts ra ise d on this diet
\

r 1

showed la rg e deposits of fat (56).

T herefore, this diet was selected

as a possible m eans of producing obese ra ts .

This diet provided

six gram s of protein, 2.25 gram s of fat, and 14 gram s of c a rb o ­
hydrate p e r 100 calo ries.
Diets C and D w ere planned to provide ratio s of p ro tein ,
fat, and carbohydrate s im ila r to the diets used in the D epartm ent
of Foods and N utrition at Michigan State College in studies with young
women (19).

Diet C contained 7.0 gram s of protein, 6.25 g ram s of

29
fat and 4.0 gram s of carbohydrate p e r 100 calo ries.

Diet D con­

tained 7.0 gram s of protein, 2.6 gram s of fat, and 14.7 gram s of
carbohydrate p e r 100 c a lo rie s.
In p re p a ra tio n of the diets, the dry ingredients w ere weighed
and mixed.

The oil was added and the diet was mixed well by hand.

Each d iet was sifted three tim es to in su re uniform distribution of the
ingredients.

The diets w ere p re p a re d once a week.

Diet C was

re frig e ra te d to p re v e n t rancidity, as it contained a higher percentage
of fat than the o th e r diets.

E xperim ental Methods

Drawing the blood sam p le.

The anim al was anesthetized

with eth er and' about 5 m illilite rs of blood w ere withdrawn from the
h e a rt using a clean^ dry syringe.

The blood was tra n s fe rre d im m e­

diately to a te s t tube from which sam ples w ere pipetted fo r analyses.

P re p a ra tio n of sample fo r body a n a ly sis.

The anim al was

sa c rific e d afte r drawing the blood sam ple, and the intestin al tra c t
was rem oved, opened, and washed.

The body was cut into sm all pieces

with strong s h e a rs , then ground th ree tim es with the in testinal tr a c t
in an e le c tric g rin d er.

If p ieces of skin wrapped around the shaft,

the g rin d e r was pulled ap a rt and the skin pieces w ere rem oved,

The

30
ground body was weighed and an equal weight of distilled w ater was
added to the ground c a rc a ss in a blender^ and blended fo r 10 m inutes.
Samples w ere withdrawn fo r m o istu re and ash determ inations.

The

rem a in d er of the ground sam ple was d ried in an evaporating dish as
in the m o istu re determ ination, then ground and dried to constant
weight.

M oisture d eterm in atio n .

The official m ethod of the A.O.A.C.

(3) fo r the determ ination of w ater in m eat was followed with slight
m odifications as follows:

Five gram s of the blended sample w ere

weighed into a platinum dish with a cover.

This was dried to con­

stant weight at 95° to 100° C entigrade.

Ash determ in atio n .

The official m ethod of the A.O.A.C. (3)

fo r the determ ination of ash in m eat was used.
gram s of the blended sam ple w ere heated at 100
the w ater was expelled.

A pproxim ately 5
o

Centigrade until

Then the dish was placed in a muffle f u r ­

nace at approxim ately '5-25° Centigrade until the sample was white.
The dish was cooled, d istilled w ater added, and the sample dried on
a hotplate to constant weight.*.

Waring Blendor.

31
P ro te in d eterm in atio n .

A m odified Kjeldahl (3) method was

used fo r the d eterm inatio n of total nitrogen content of the body.

One-

half to 1 gram of the dried sample was weighed and a m ixture of
sodium sulfate and copper sulfate was added as a catalyst.

P ro ­

tein was e x p re sse d as gram n itrogen x 6.25.

F a t d eterm in atio n .
was followed.

The official method of the A.O.A.C. (3)

E xactly 2 gram s of the d ried sam ple w ere tra n s fe rre d

into a p re p a re d Gooch crucible (having a thin la y er of asbestos).

The

sample was co.yered with ex tracted cotton and d ried fo r five hours
at 105° Centigrade, then cooled and weighed.

The

sam ple was ex-

'
1
o
tra c te d fo r sixteen ’h durs With eth er, dried at 105 Centigrade fo r
three hours, and weighed to determ ine the eth er extract.

Blood p o ta ssiu m .

The method developed by O verm and and

Davis (79) and rev ised by Hunter (51) was used fo r the determ ination
of potassium in whole blood.

As soon as possible a fte r the c o lle c ­

tion of the blood sam ple, 1 m illilite r of blood was delivered into a
100 m illilite r volum etric flask containing 10 m illilite rs of a solution
of lithium chloride equivalent to 0.01 p e r cent lithium and approxi­
m ately 30 m illilite rs of w ater.

A fter hem olysis was completed, 4

m illilite rs of 20 p e r cent tric h lo ra c e tic acid was added.

The solution

32
was allowed to stand fo r ten m inutes before diluting to volume.

The

sample was centrifuged and the c le a r solution was analyzed for po­
tassium., using a P e rk in -F lm e r flam e photom eter.

Standard solutions,

p re p a re d to contain 0 to 5 m illig ram s p e r cent of potassium and 10
m illig ram s p e r cent (100 ppm) of lithium w ere analyzed with each
determ ination.

A typical standard curve is shown in F ig u re 1.

Blood values of potassium w ere e x p ressed as p a rts p e r m illion.

Blood c h o le ste ro l.

1

The concentration of total cholesterol in

blood seru m w as determ ined by the method of Schoenheim er and
S p erry (91), w ith m odifications according to S p erry and Brand (100),
Sobel and M ayer (98), and Foldes and Wilson (37).

T hree m illilite rs

of alcohol-acetone (1:1) solution w ere added to 0.2 m illilite r of serum
in a 5 m illilite r volum etric flask.

The solution was brought to b o il­

ing and held at this te m p eratu re fo r th irty seconds.
was cooled and made to volume.

The solution

The protein p recip itate was sep arated

fro m the e x tra c t by filtra tio n through fa t-fre e f ilte r p ap er.
S

An aliquot

i- *

of 1 m illilite r of e x tra c t was used fo r the determ ination of total
ch o lestero l.

The ch o lestero l was p recip itated with a 50 p e r cent

Acknowledgment is made to M rs. H. C. Amen and Miss
M. M ills fo r the determ ination of blood cholesterol and blood pyruvic
acid values.

F igure 1.

Standard curve fo r potassium determ ination.

4

3

Parts

Per

Million

P o tassiu m

5

2

1

20

40

60

80

F lam e P h otom eter Readings

10 0

34
alcoholic digitonin solution and allowed to stand overnight.

The p r e ­

cipitate was sep arated by centrifuging and then washed with an acetone
eth e r solution and with anhydrous e th e r.

The e th e r was rem oved by

evaporation.
The digitonin p recip itate was dissolved in glacial acetic acid
and a solution of acetic an hydride-sulfuric acid (20:1) was added.
The solution was allowed to stand fo r tw enty-seven m inutes (no
longer than th irty minutes) and the absorption of light was m easu red
in a Beckm an spectrophotom eter at a wave length of 620 m illim i­
crons.

D eterm inations of seru m ch o lestero l w ere made in duplicate

w henever possible; however, in some instances insufficient blood was
obtained to p e rm it duplicate analysis.

A s e rie s of solutions of 0.01

to 0.10 m illig ram of p u re cho lesterol p e r m illilite r of acetic acid
was p re p a re d and tre a te d according to the above proced ure.

The

absorption of light was m easu red and the values were plotted on
sem i-lo g arith m ic p ap er against the concentrations of cho lestero l.
The graph was used as a referen ce curve fo r the calculation of chol­
e s te ro l in blood serum .

Blood pyruvic acid.

The m icro-m etho d developed by Tsao

and Brown (108) was used .for the determ ination of pyruvic acid.
A fter centrifugation of the p recip itated blood sam ple, 0.1 m illilite r

35
of the c le a r su p em atan t m etaphosphoric acid solution was tra n s fe rre d
to a sm all re a c tio n tube, using a co n strictio n pipette.

To each tube,

33 m illilite r s of 2, 4 dinitrophenylhydrazine reagen t w ere added and
the contents w ere m ixed by shaking.
100 m illilite r s of xylene.

To this m ixture was added

The tubes w ere stoppered and shaken in a

horizontal p ositio n fo r two m inutes with a Kahn shaker.

A fter shak­

ing, the tubes w ere centrifuged at 2,500 revolutions p e r minute fo r
five m inutes.

The bottom la y e r was rem oved com pletely by m eans

of a fine c a p illa ry pipette and discarded.

The hydrazone of pyruvic

acid was then e x tra cted fro m the xylene la y e r by adding 100 m illi­
lite r s of 10 p e r cent sodium carbonate solution and shaking fo r three
m inutes.

Subsequently, the tubes w ere centrifuged at 2,500 rev o lu ­

tions p e r m inute fo r six m inutes.

With a co nstriction pipette, 75

m illilite rs of the low er carbonate la y er was tr a n s fe rre d to a m ic ro cuvette, 2 x 10 x 25 m illim e te rs.
the' xylene to the m icrocuvette.

C are was taken not to tra n s fe r
Eighteen m illilite rs of approxim ately

seven N sodium hydroxide w ere added and the contents of the cuvette
m ixed im m ediately by blowing a ir gently through the pipette.

The

optical density at a w ave-length of 520 m illim icrons was read in the
Beckman spectrop hotom eter with the m icro attachm ent p ro p erly aligned.
The apparatus was set to 100 p e r cent tra n sm issio n by means of a

w ater blank.

All readings w ere made between two and th ree minutes

a fte r the color developed.
Standard solutions containing 1.00, 3.00, and 5.00 m illigram s
p e r cent pyruvic acid w ere p re p a re d from the 100 p e r cent stock
stand ard solution.

The standards and the reagent blank w ere run

sim ultaneously and in trip lic a te in exactly the sam e m anner as the
blood sam ples, including the 1:5 dilution with m etaphosphoric acid.

DATA AND DISCUSSION

P e rio d of Weight Gain

Weight gain.

D aring the p erio d of weight gain of twenty-one

weeks, the anim als were fed and w atered ad libitum .

The weekly

gain of r a ts on the com diet v a rie d fro m -0.8 to 12.8 g ram s, a v e r ­
aging 2.66 gram s p e r week; and on the wheat diet, from -0.4 to 11.6
gram s, averaging 2.83 g ram s p e r week (Table 2).

The growth curves

of both diets w ere found to be sim ila r to that re p o rte d by King (60)
(Figure 2), and the re g re s s io n coefficients fo r the two diets did not
differ significantly (F ish e r t test) (Figure 3).

On the corn diet, the

total weight gained v arie d from 19 to 104 g ram s, averaging 55.9
gram s; and on the wheat diet, fro m 10 to 89 g ram s, averaging 50.4
gram s.

There was no significant difference in weight gained between

the two diets (Table 3).

The final weights of the ra ts on the co m

diet v a rie d from 191 to 263 g ram s, averaging 220 gram s; and on the
wheat diet, v a rie d from 170 to 250 g ram s, averaging 215 gram s.
The rats fed the corn diet consumed an average of 253.4
calo ries p e r week, while those on wheat diet consumed an average
of 261.1 calo ries p e r week.

These intakes w ere le ss than those

38
Table 2.

Weekson Ex­
perim en t

Average weight, gain in weight, food and caloric consumption of ra ts during the period of weight gain.

Diets

No. of
Rats

Av. Wt.
of Rat

Av. Gain
in Wt.

Av. Daily Food
Consumption
Amount

(gm)

(gm)

(gm)

C alories

Wheat
Corn

39
87

167.8
176.8

11.6
12.8

68.2
78.7

38.9
38.9

Wheat
Corn

39
87

173.2
182.0

5.7
5.2

66.4
68.2

37.9
36.7

Wheat
Corn

39
87

178.6
186.7

5.4
4.7

68.3
64.0

39.0
34.4

Wheat
Corn

39
87

181.2
191.2

2.6
4.5

68.0
68.3

38.9
36.7

Wheat
Corn

39
87

183.8
194.6

2.6
3.4

65.4
70.5

37.4
37.9

Wheat
Corn

37
85

186.6
198.5

2.8
3.9

64.8
67.6

37.0
36.3

Wheat
C om

35
83

189.5
200.2

2.9
1.7

65. 1
66.4

37.1
35.7

Wheat
Corn

33
80

192.7
203.5

3.4
3.3

65.9
69.3

37.7
37.3

Wheat
Corn

31
78

194.8
205.8

1.9
2.3

64.0
66.5

36.7
36.7

Wheat
Corn

29
76

196.9
209.1

2.1
3.3

63.5
65.0

36.3
34.9

39
T a b l e 2 (C o n tin u e d )

Weeks
on E x­
p erim en t

Diets

No. of
Rats

Av. Wt.
of Rat

Av. Gain
in Wt.

Av. Daily Food
Consumption
Amount

> <>
\ (gxn)

(gm)

(gm)

C alories

11

Wheat
Corn

27
74

200.4
208.9

3.5
-0.2

65.1
59.5

37.1
32.0

12

Wheat
Corn

25
72

204.1
210.0

3.7
2.0

64.8
66.5

37.0
35.6

13

Wheat
Corn

25
72

206.7
211.9

2.6
1.0

66.2
66.6

37.9
35.7

14

Wheat
Corn

24
70

207.1
213.0

0.4
1.1

62.4
68.2

35.7
36.6

15

Wheat
Corn

24
70

208.6
214.9

1.5
1.9

63.3
74.2

36.3
39.9

16

Wheat
Corn

22
68

210.1
214.9

1.5
0.0

65.2
63.5

37.3
34.1

17

Wheat
Corn

22
68

213.2
219.3

3.1
4.4

64.8
78.5

37.0
42.1

18

Wheat
Corn

20
66

212.8
220.2

-0.4
0.9

63.8
68.3

36.5
36.7

19

Wheat
Corn

20
66

211.9
222.0

-0.9
1.8

62.9
74.4

36.0
40.0

20

Wheat
Corn

19
64

214.4
220.7

2.5
-1.3

66.7
58.6

38.1
31.4

21

Wheat
Corn

19
64

215.3
219.9

0.9
-0.8

65.2
59.3

37.3
31.9

Figure 2.

Graph showing ra te of growth of ra ts fed corn and wheat diets com pared with ra te
of growth rep o rted by King (60).

220

Weight in G ram s

200

-

Wheat Diet
Corn Diet
170
2

4

6

8

10

12

Time in Weeks

14

16

18

20

o

41

F igure 3.

R egression of weight gain on tim e of diet during period of
weight gain.

Corn Diet

y = 18.2 + 2.8X
S .E . 12.8

100

90

-

_

x

—

x -

Wheat Diet

y = 17.8 + 2.9X
S.E. 13.4

x
X

70

w eigirc

uain

m

u ra m s

80

o

60
50
40

30
20

or1

10

12

14

Time in Weeks

16

is”

42
Table 3.

Average weight gain of ra ts on corn and wheat diet d u r­
ing period of weight gain.

Gm Gain in
Weight

A nalysis of V ariable

Wheat
Diet

Corn
Diet

No. of
Rats

50.40

55.90

130

_
,
Sample

P re d ic te d F Value

F Value

S%

1%

0.11

3.07

4.78

43
calculated from the p redicting equation published by H arte, T ra v e rs,
and S arich (45).

According to this equation, the corn-fed ra ts with

an average weight of 20 6 g ram s would voluntarily consume an a v e r­
age of 345 c a lo rie s p e r week (12,5 calo ries p e r square d ecim eter of
body surface p e r day) to obtain a no rm al growth and the w heat-fed
r a ts , with an average weight of 200 gram s, would consume an average
of 339.5 c a lo rie s p e r week.
These data suggest th at the corn and wheat diets used in this
experim ent supported n o rm al growth without the development of obesity,
which had been observed p reviously in anim als fed the corn diet (56).
However, som e raj:s on-both diets reached weights which w ere about
15 p e r cent g re a te r than the group average and therefo re m ight be
considered to be obese if obesity is in te rp re te d as excess body
weight.

Body com position.

The m oisture content of the c a rc a s s e s of

ra ts fed the w heat diet averaged 62 p e r cent, and those
fed the corn diet averaged 58.9 p er cent (Table 4).
ence was found to be significant (Table 5).

This d iffe r­

However, when the m o is ­

tu re content was calculated on a fa t-fre e b a sis, the p er cent of
w ater in the ra ts fed the corn and wheat diets averaged 70.6 and
70.4, respectively, and w ere found not to differ significantly.

The

44

Table 4.

Body
Constituents

The average body composition of r a ts during the period of
weight gain.

7th Week
.

8th Week

9th Week

10th Week

12th

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __________ ______

Wheat Corn Wheat Corn Wheat Corn Wheat Corn Wheat
Diet
Diet Diet
Diet Diet
Diet Diet
Diet Diet
F r e s h B asis

P ro te in

16.8

17.4

18.7

17.4

17.6

17.1

18.0

17.0

18.1

(%)

W ater (%)

64.2

5913

60:9

6o;o

61.6

58.7

62.3

60.4

61.7

F a t (%)

13.2

17.0

14.7

16.8

13.5

16.5

12.2

15.5

12.2

Ash ( %)

4.2

3.6

3.6

3.5

3.9

3.4

3.9

3.9

3.9

F a t - F r e e B asis
P ro te in

18.3

20.9

21.5

20.9

21.1

20.4

21.4

20.7

20.7

70.0

71.3

7Q.I

72'. i*

70A

72.1

70.7

70.8

70.2

4.8

4.3

4.5

4.4

4.5

4.7

4.4

(%)

W ater (%)
Ash (%)

4.1-

4.2

45
T a b le 4 (C o n tin u e d )

Week

14th. Week

1 6th Week

18th 'Week

20th. Week

Average
for the
P e rio d

Corn Wheat Corn Wheat Corn Wheat Corn Wheat Corn Wheat Corn
Diet Diet
Diet Diet
Diet Diet
Diet Diet
Diet Diet
Diet
F r e s h Basis
17.6

18.1

17.5

. 17.8

16.5

17.5

17.6

18.0

18.7

17.8±
2.7

17.4±
1.3

57:6

63:1

59.3

61 !5

57:8

59.8

56!5

63; 9

60:7

62.0±
3.24

58.9±
2.73

18.4

11.3

15.9

12.3

22.9

15.7

18.6

9.5

13.3

12.8±
1.7

17.2±
3.8

4.0

4.0

4.0

4.0

3.6

3.8

3.7

4.0

4.0

3.9±
0.43

3 .7±
0.11

F at- F r e e Basis

20.8

21.4

21.0

20.3

20.1

20.6

21.7

20.8

21.5

20.7

20.9

70.2

71.0

69.5

70.2

70.2

70.4

69.2

70.6

70.0

70.4

70.6

4.9

4.5

4.4

4.6

4.5

4.5

4.6

4.5

4.6

4.5

4.5

46
Table 5.

The average body composition of corn and wheat fed ra ts
(period of weight gain) and analysis of variance.

Analysis of Variance
Average Body Composition
Wheat
Diet

i
No. of
Rats

Corn
Diet

Sampled
F Value

e di c t e d.
F Value

5%

1%

4.13

7.44

4.13

7.44

F re s h B asis
P r o te in ( %)

17.80

17.40

Water { %)

62.00

58.90

36

Ash (%)

3.90

3.70

36

2.90

4.13

7.44

F a t ( %)

12.80

17.20

36

7.44**

4.13

7.44

v*

36

3.10
10.00**

F a t - F r e e B asis
P ro te in (%)

20.66

20.93

36

0.64

4.13

7.44

Water (%)

70.39

70.60

36

0.25

4.13

7.44

4.48

4.50

36

0.06

4.13

7.44

Ash { %)

* F r o m Snedecor, G. W.
** Highly significant.

S tatistical M ethods, Table 10.3.

47
rats fed the c o m diet showed a tendency to lose m o istu re, while
those on the wheat diet showed a tendency to gain w ater as they grew
older.

There w as, however, no c o rre la tio n between time on the diet

and m oisture content (Table 6), and the slopes of the corn and wheat
diet curves were not significantly different (Figure 4).

Data obtained

showed that th ere was a c o rre la tio n between fat content and the m o is ­
tu r e content of the body in wheat-fed ra ts, but not in the corn-fed
r a ts .

The amount of w ater d e c re a se d as the amount of fat in c re ased

(Figure 5).
The average p ro tein content of the r a ts was 17.4 and 17.8
p e r cent, respectively, fo r the corn and wheat diets on the fre s h
weight b asis, and 20.9 and 20.7 p e r cent, respectively, on the f a t- f r e e
b a s is (Table 4).

The differences were not significant (Table 5) and

no co rrelatio n was observed between the time on the diet and the p r o ­
tein content of the rats fo r e ith er diet (Table 6); the slopes of the
c o m and the wheat diet curves were not significantly different (F ig ­
u re 6),
The ra ts on the corn diet had an average ash content of 3.7
p e r cent and those on the wheat diet, 3.9 p e r cent (Table 4).

The

ash contents ,w ere not significantly different (Table 5), and as was
the case for the protein contents, no co rrelatio n was found between
ir.

<•
..

su\
V

i'i

.

48
Table 6.

C o rre la tio n coefficient of body weight, body constituents,
and tim e on diet of r a ts during the period of weight gain.

No. of
O bser­
vations

D egrees
of
F reedom

18
18

16
16

18
18

16
16

Body content
Wheat
of fa t and body Corn
content of w ater

18
18

Time on diet
and protein
content

Wheat
Corn

Time on diet
and w ater con­
tent of body

V ariables

Diet

Sample
Value
of r

P re d ic te d
r Value
5%

1%

0.47
0.47

0.59
0.59

-0.34
0.01

0.47
0.47

0.59
0.59

16
16

-0.90**
-0.03

0.47
0.47

0.59
0.59

18
18

16
16

0.03
0.56*

0.47
0.47

0.59
0.59

Wheat
Corn

18
18

16
16

0.07
0.06

0.47
0.47

0.59
0.59

Time on diet
and ash con­
tent of body

Wheat
Corn

18
18

16
16

0.02
0.35

0.47
0.47

0.59
0.59

Body weight
and content of
fat

Wheat
Corn

18
18

16
16

0,18
0.6 4* *

0.47
0.47

0.59
0.59

Time on diet
and gain in
weight

Wheat
Corn

Time on diet
and body c o n - ’
tent of fat

WJipat
Corn

'

* Significant.
** Highly significant.

0.72**
0,73* *

F ig u re

4.

R e g r e s s i o n of m o i s t u r e c o n t e n t o n t i m e d u r i n g th e p e r i o d of w e i g h t g a in .

75

P erc en t Body

Moisture

■> o

X

70

Corn Diet

y = 59.28 - 0.04X
S.E. = 2.73

Wheat Diet

y 31 61.9 + 0.01 X
S.E. = 3.24

65

x
x
-

60

oX.

*

*
*

X

10

_L
12

55

14

16

18

20

Time in Weeks
vO

Figure 5.

R egression of body m o istu re content on body fat during period of weight gain.

20

\

18

° \

F at

X
X

°

Percent

Wheat Diet

y = 106.00 - 1.48X
S.E. 3..67

7

Corn Diet

y 3 18.60 - 0.03X
S.E. = 3.90

o

-

16

7X

o
..

V.

X

r

oX

X

x
X
X

1 4 i-

X
X

X
X

12 j-

X X
\*

X X
X

10

X h
58

59

60

61

62
P e r c e n t Water

63

64

65

6b

in
o

F i g u r e 6.

Corn Diet
-

—, X Wheat Diet

y =

16.. 60 + 0.08X
S.E. = 1.29

y

17.80 + 0.01 X
S.E. = 2.7

20

Percent

P ro te in

22

R e g r e s s i o n of p r o t e i n c o n t e n t on t i m e d u r i n g p e r i o d of w e i g h t g a in .

18
o
X

16

L

-L______!—____!______L_
7
8
9
10

,~L_.

12

14

Time in Weeks

16

18

_L_
20

52

time on the diet and ash content (Table 6), and also no difference in
the slopes of the two diet curves was found (Figure 7).

On the fa t-

free b a s is , the average ash content was 4.5 per cent for both diets
(Table 5).
Spray (101) found that the w ater, protein, and ash contents
of m ature rats w ere stable when calculated on a fa t-fre e b asis.

The

data obtained in this study are in good agreem ent with h e r re su lts
(Table. 5).
Although no significant differences were found between the
weights' of the ra ts fed the corn and wheat diets (Table 3), the p e r
cent of body fat differed significantly for the two groups (Table 5).
The rats on the corn diet had an average of 17.2 p e r cent fat and
those on the wheat diet, 12.8 p e r cent (Table 4).

The la r g e r deposi­

tion of fat o ccu rred in the ra ts on the corn diet even though the co rn
diet had a lower fat content than the wheat diet (8.6 p e r cent as
com pared to 10.1 p e r cent) and the caloric intake on the corn diet
was le s s .

These re su lts are not in agreem ent with those of Wynn

and Haldi (113), who rep o rted that the amount of fat in the diet had
a definite effect on the amount of fat in the body but appeared to
agree with those of Scheer et al. (90) and others (23) who stated that
the fat content of the body was not related to the fat content of the

Figure 7.

R egression of ash on time during period of weight gain

5.0 —

*

Corn Diet

y = 3,38 + 0.045X ± C. 11
S.E. = 0.11

Wheat Diet

y = 3.86 + 0.004 X ± 0.43
S.E. = 0.43

4.5
x
X

.

0

0

0
X

4.0 I-

_
X

*
j S.

_ _ _

x
o'
X

3.5 u

-O'
o

x
o

x

X

54
diet.

The

content of b o d y f a t of the rats fed on the wheat diet tended

to d e c r e a s e as the r a t s
ment with, the r e s u lts

g r e w older (Figure 8).

r e p o r t e d by Spray (10 1).

This is in a g r e e ­
No co rrelatio n was

found b e t w e e n body w e i g h t and the content of body fat (Figure 9).
data f o r r a t s fed th e

com

age and b o d y fat c o n t e n t
tween th e

The

diet showed no c o rre la tio n between th e ir
(T ab le 6), but there was a co rrelatio n b e ­

body w eig h t a n d

the fat content of the body (Figure 9,

Table 6).
If

obesity i s d e f i n e d as the p er cent of fat in the body rath e r

than as l i v e weight, th e
since th e

c o r n - f e d ra ts might be considered obese

c a r c a s s e s of t h e

rats fed the corn diet contained signifi­

cantly m o r e fat than t h o s e
than th a t

rats fed the wheat diet, and also m ore

rep o rte d b y s e v e r a l investigators (21, 47, 60) as the a v e r ­

age for r a t s exhibiting n o r m a l growth.

B lo o d c o n stitu e n ts.
trol w h e a t

The blood cholesterol of rats fed the con­

diet v a r i e d f r o m

liters w ith , an a v e r a g e o f

40.8 to 83.3 m illig ram s p e r 100 m illi­

6 9 . 8 m illigram s p e r 100 m illilite rs of

serum, a n d was h i g h e r t h a n the values fo r the ra ts fed the corn diet
which v a r i e d from 34.5 t o

90.0 m illigram s with an average of 62.6

m illig ra m s per 100 m i l l i l i t e r s of serum (Table 7).
was found, to be s i g n i f i c a n t (Table 8).

This difference

The amount of cholesterol in

55
Figure 8.

R egression of body fat content on time during period of
weight gain.

— — —, x
-----jo

Wheat diet

Corn diet

y = 14.53 - 0.18 X
S.E. = 3.5
y = 17.08 + 0.01 X
S.E. = 3.85

22

Percent

F at

20

18

16

14-

12-

J

L
10

12

14

Time in Weeks

16

18

_±
20

F ig u re

22

9.

R e g r e s s i o n of b o d y w e ig h t o n f a t c o n t e n t d u r i n g p e r i o d of w e ig h t g a in .

—?X

Wheat Diet

y * 13.12 - 0.001X

o Corn Diet
20

3.24

Fat

S.E.

Percent

Body

18 -

16

oo

14
X

12

X

-

X

10
170

180

190

200

210

220
W e ig h t i n G r a m s

230

240

250

57
Table 7.

Blood cholesterole, pyruvic acid, and potassium of r a ts
during the period of weight gain

7th Week

8th Week

9th Week

10th Week

12 th

Blood
Wheat Corn Wheat Corn Wheat Corn Wheat Corn Wheat
Diet Diet
Diet Diet
Diet
Diet Diet
Diet Diet
C holes­
te ro l
(mg/100
ml)

58.41

P yruvic
Acid (m g/
100 ml)

.2.60

P o ta s s iu m

15Q

60.30 83.29

1.59

^

67.51

40.78

1.96

1.95

1.46

.2lQ

^

lg6

34.50 78.12 46.51

3.93

^

2.38

^

2.14

lg4

76.30

--

lgg

58
T a b l e 7 (C o n tin u e d )

Week

14th Week

16th Week

Corn Wheat Corn Wheat
Diet Diet
Diet Diet

77.12

186

78.43

90.00 76.50

2.37

2.00 . 2.71

20.2

311

183

18th Week

20th Week

Average
for the
P erio d

Corn Wheat Corn Wheat Corn Wheat Corn
Diet Diet
Diet Diet
Diet Diet
Diet

72.34 67.81

2.83

198

2.47

183

sf

77.72 82.68

57.67

2.06

1.55

2.46

185

160

184

69.80 62.60

2.22

174.6

2.30

189.9

59
Table 8.

The average blood constituents of ra ts during the period
of weight gain.
Average
Blood Content

Blood
Constituents

Wheat
Diet

Cholesterol (mg/
100 ml)

Corn
Diet

Analysis of Variance

No. of
Rats

Sampled
F. Value

P red icted
F Value
5%

1%

69.80

62.60

34

6.45*

4.-13

7.44

2.22

2.30

30

1.00

4.20

7.64

• 174.60

189.90

34

4.70*

4.15

7.50

P yruvic acid
(mg/ml)
. /
»

P o tassiu m (ppm)

Significant.

60
the blood seru m tended to in c re a s e with the time the rats were on
the experim ent during the weight-gain period (Figure 10).

This may-

r e p r e s e n t the no rm al in crease of serum cholesterol with age, since
the data obtained by Keys and co-w orkers (58) indicated that there
was an average in c re ase of 2.2 m illigram s of total cholesterol p e r
100 m illilite rs of serum p e r year fo r humans m ore than thirty y ears
of age.
F o r r a ts on the wheat diet, the blood cholesterol concentration
d ecrea se d as the body fat content of rats increased, while for the
ra ts on the co rn diet no relation was found between the blood choles­
te ro l concentration and body fat content (Figure 11).

As the rats

fed the corn diet were found to have a lower average blood choles­
te ro l concentration than those of the rats fed the control wheat diet,
and since the ra ts on the control wheat diet which had a higher con­
tent of body fat than the average were found also to have lower chol­
e ste ro l values than the average, it might be concluded that the depo­
sition of fat was associated with low cholesterol values.

This is in

agreem ent with the resu lts of Elliott and Nuzum (30), who reported
that obese p erso n s have low er cholesterol values than underweight
p erso n s.

F ig u re

10.

R e g r e s s i o n of c h o l e s t e r o l on t i m e d u r i n g p e r i o d of w e i g h t g a in .
') °'r corn diet

Mg. Cholesterol

per

100 Ml. of Blood

Serum

wheat diet

y = 55.85 + 1.50X
S.E. = 19.89
y

35.40 + 2.89X
S.E. = 20.39

90

80

O
K
70

60

X
50

_L .

9

...

10

12

14

T im e in W eeks

O'

_l_

16

18

20

F ig u re

11..

R e g r e s s i o n of c h o l e s t e r o l on b o d y f a t.

----------- 5 °

Corn Diet

y = 59.0 + 0.4X
S.E. = 19.1

X Wheat Diet

-

90

70

Mg. Cholesterol

per

100 Ml. of Blood

Serum

■».

110

x

50
40

0

-i
11

12

13

14

I______i______L
16
18
P e rc e n t Body F at

20

_i--------- |_
22

y = 99.3 - 2,3 X
S.E. = 20.1

63
The potassium content of the blood of the rats on the corn diet
ranged fro m 163 t o '211 p a rts p e r million, with an average of 189.9
p a rts p e r million; fo r ra.t$, on the wheat diet the blood potassium val*
s’
*
ues ranged fro m 150' to 2.1,0. p a rts p e r million, with an average of
174.6 p a rts p e r million during the gaining period (Table 7).

The

difference in potassium content of the blood of the rats on the two
diets was found to be significant (Table 8).
There was no co rre la tio n between the time of weight gain and
potassium content of the blood (Table 9), but there was a tendency
for the blood potassium of ra ts to decrease the longer the ra ts were
on the weight-gaining diet (Figure 12).

These results are not in a g r e e ­

ment with those of Benetato and Curdain (9), who found that blood
potassium of rats seem ed to in crease with age.
The blood potassium content of the ra ts tended to increase
with an in c re ase in body fat content on both wheat and corn diets
(Figure 13).

The rate of in crease was m ost pronounced in the rats

fed the wheat diet.

The slower rate of in crease in blood potassium

on the corn diet may be explained by the fact that the corn-fed rats
attained a higher blood potassium content n e a r the s t a r t of the gaining period which seem ed to be n ear the maximum.

F i g u r e 1 2.

R e g r e s s i o n of p o t a s s i u m on t i m e d u r i n g p e r i o d of w e ig h t g a in .

177.00 - 0.39X
S.E. = 24.60

Wheat Diet

y

Corn Diet

y = 199,30
0.65X
S.E. = 15.28

220

O

X

200

CP

00
180

O
o

X

Parts

Per

Million

Potassium

in Blood

240

X

160

X

140

L_, _]-------1----- 1-----1—
7

8

9

10

12

J .
14

T im e in W eeks

16

18

20

o

t_n

F ig u re

13-

R e g r e s s i o n of p o t a s s i u m on f a t c o n t e n t d u r i n g p e r i o d of w e ig h t g a in .'

,
220.

V____ ,o Corn Diet

y = 134.9 + 3 .IX
S.E. = 24.1
y = 179.6 + 6X
S.E. = 16.7

.

°

200

1 80-

><

X

O

Parts

Per

Million

Potassium, in Blood

>XWheat Diet

160

140
20
P e rc e n t Body F at

67
The pyruvic acid content of the blood v arie d from 1.46 to
2.71 m illig ram s p e r 100 m illilite rs of blood, averaging 2.2 m illigram s
during the perio d of weight gain on the corn and wheat diets (Table
7).

No significant differences were found between the two diets

(Table 8)

and no difference between the slopes of the two curves

was found (Figure 14).

There was no co rrelatio n between the time

on ..the diets and the pyruvic acid content of the blood (Table 9).
The blood pyruvic acid content in c re ased with an inc rease
in the body fa t content (Figure 15).

This was m ost pronounced in

the blood of the ra ts fed the corn diet.

Although the co rrelatio n

coefficients between the in c re ase in blood pyruvic acid and in crease
in body fat contents were not significant (Table 9), the resu lts ob­
tained with the ra ts fed the corn diet suggested that the deposition
of fat might be associated with a change in carbohydrate metabolism,
as pyruvic acid concentration in creased in ra ts that deposited fat.

P e rio d of Weight Loss

Control a n im a ls.

During the period of weight loss the control

ra ts which were fed i:he wheat, diet ad libitum gained fro m -2.0 gram s
> i'*
to 4.3 gram s p e r rat. p e r week, with an average weekly gain of 0.65
..

„.

g ram s p e r r a t (Table 10).

F i g u r e 14.

R e g r e s s i o n of p y r u v i c a c i d on t i m e d u r i n g p e r i o d of w e ig h t g a in .

100 Ml. of Blood

3.0

per

O

2.5

>*

y = 1.97 + 0.02X
S.E. = 0.70

corn diet

y =

2. 30 + O.dx
S.E. =* 0.1}7

Acid
Mg. Pyruvic

wheat diet

_

2.0 i-

o
X

—

X
x
x

&

1.5

-I ___________ I___ ________ L _
10
12
14
T im e in W eeks

I
16

... ..

•

.J___________ L
18

20

os

00

r

R egression of body fat on pyruvic acid during period of weight gain.

2.8

sX

Wheat Diet

y = 1.54 + 0..06X
S.E. = 0.18 !

■y o

Corn Diet

y

= 1.52 + 0.12X„
S.E. = 0.16 t-

-

•Mg. Pyruvic

Acid

per

100 Ml.

of Blood

Figure 15.

2.6

2,4

x
2. 0

X

O
X

1.8
10

12

14

" 16

P e rc e n t Body F a t

18

20

O'
v£>

70
Table 10.

Average changes in weight of r a t s during the period of
weight loss.
Week

Changes in Weight
1
(gm)

3
(gm)

(gm)

Low carbohydrate diet

-20.13

-7.00

-6.70

High carbohydrate diet

-20.73

-7.80

-5.00

-2.00

+4.32

+ 1.00

Wheat diet

.
.u\

Table 9.

.

.
'

C orrelation coefficient of blood constituents and time on
• diet of rats during the period of weight gain.

Diet

No. of
Rats

Degrees
of
F reedom

S ample
Value
of r

P red icted
Value
of r
5%

1%

0.497
0.497

0.623
0.623

Time on diet
and blood cho­
le ste ro l

Wheat
Corn

16
16

14
14

Cholesterol and
body fat

Wheat
Corn

16
16

14
14

-0.265
0,080

0.497
0.497

0.623
0.623

Time on diet
and pyruvic
acid in blood

Wheat
Corn

16
16

14
14

0.137
0.007

0.497
0.497

0.623
0.623

Time on diet
and potassium
in blood

Wheat
Corn

16
16

14
14

-0,060
-0.155

0.497
0.497.

0.623
0.623

Body content
of fat and .po­
ta ssiu m in
blood

Wheat
Corn

16
16

14
14

0.248
0.328

0.497
0.497

0.623
0.623

Body content
of fat and
blood pyruvic
acid

Wheat
Corn

15
15

13
13

0.018
0.321

0.514
0.514

0.641
0.641

* Significant.

*

64
i

0.257
0.519*

71
T a b l e 10 (C o n tin u e d )

Week
4

5

6

7

8

Average,
Total
P erio d

(gm)

(gm)

(gm)

(gm)

(gm)

(gm)

-9.61

-8.02

-9.87

-15.25

-10.61

-87.20

-5.40

-10.00

-11.30

-11.90

-10.18

-82.21

-0.53

+2.32

-0.61

+ 1.33

-0.62

+5.10

72
The body composition of the ra ts fed the control wheat diet
rem ained rela tiv ely constant during the period of weight loss, e s ­
pecially when the values were calculated on a fa t-fre e b asis (Table
12).

The average body content of fat, w ater, protein, and ash, c a l­

culated on a f r e s h weight basis was 16.4 ± 1.7, 59.3 ± 3.2, 17.6 ± 1.3,
and 3.8 ± 0.4 per cent, respectively (Table 13).

The constancy of

the various components which were analyzed during the period indi­
cated that age p e r se of the animals had no apparent influence on
the facto rs studied.

Therefore, it might be expected that any changes

observed while- the anitnals were fed the re s tr ic te d diets could be a s ­
sociated with the diet1,of the animals and was not an effect produced by aging.
i

(i
r

Weight l o s s . -There is no agreem ent among investigators on
the relative effects of high-fat, low-carbohydrate diets and low-fat,
high-carbohydrate diets on the rate of weight loss of individuals.

In

this study, r a ts that were r e s tr ic te d to an intake of 12 calo ries p e r
day lo st an average of 82.21 gram s over a period of eight weeks
when a low -carbohydrate diet (Diet C) was fed, and 87.19 gram s when
a high-carbohydrate diet (Diet D) was fed.

These lo sses r e p re s e n t

an average of 35.3 and 37.4 p e r cent, respectively, of the original
weights of the ra ts (Table 10).

The differences between the total

lo s s e s w ere not significant (Table 11), and the re g re ssio n coefficients

T a b l e 11.

C h a n g e s i n w e i g h t of r a t s d u r i n g p e r i o d of w e i g h t l o s s .
Analysis of Variance

G ram s Change in Weight
Wheat
Diet

Low
Carbo­
hydrate

r r e u ic ie o
Value
of F
----------- -------

High
C arbo­
hydrate
t

+5.10

-82.21

-87.19

68.30**

5%

L.S.D. .
----- — -----—
5 oj0
Xaj0

1%

3.47 5.78

12.17

16.35

4

74
Table 1 2 .

The average body composition of r a ts during the period
of weight loss.
Week

-

Body
Con­
stit­
uent

.

.

1
Diet

A

C

D

A

2

3

4

Diet

Diet

D ie t

C

D

A

C

D

A

C

D

F re s h Weight
F at

17.8

18.3

16.0

15.3

12.2

17.0

17.5

10.6

6.9

17.5

12.0

9.5

58.2

58.8

58.3

60.5

60.7

55.3

56.5

62.5

65.4

58.8

60.7

61.3

17.5

16.6

18.7

17.4

18.7

17.4

18.8

19.5

20 .0

17.3

20.6

21.1

4.2

3.8

4.2

4.1

4.1

4.5

5.0

3.9

4.1

4.2

(%)
Water
(%)
P ro ­
tein
(%)
Ash

3.4

3.8

(%)
F a t - F r e e Weight
Water

70.9

72.1

69.6

71.4

69.1

66.6

68.5

70.0

70.3

70.4

69.0

67.6

21.2

20.3

22.2

21.2

2 1.2

21.1

22.8

21.8

21.5

20.8

23.4

23.4

4.1

4.6

5.0

4.4

4.8

5.0

5.0

5.0

5.4

4.7

4.7

4.7

(%)
P ro ­
tein
(%)
Ash
(%)

75
T a b l e 12 ( C o n tin u e d )

Week

A

5

6

7

8

Diet

Diet

Diet

Diet

C

D

A

C

D

A

C

D

A

C

D

F re s h Weight
18.5

12.5

6.1

14.2

3.5

6.1

13.2

3.6

8.2

17.6

2.8

4.0

58.0

59.2

64.7

61.0

66.0

71.9

62.8

66.4

62.1

58.9

68.7

67.6

16.8

21.1

21.4

18.1

21.7

16.2

17.0

22.4

23.1

17.7

21.3

21.8

3.3

4.1

5.1

4.2

5.5

'*3.9

4.2

5.4

4.2

F a t - F r e e Weight
71.2

67.6

69.0

71.1

68.3

70.3

72.3

69.0

67.7

70.7

71.0

70.5

20.6

24.2

22.8

21.1

22.5

22.0

14.7

23.3

25.1

21.2

21.9

22.6

4.1

4.8

5.4

4.9

5.8

5.3

4.8

5.6

4.9

--

--

T a b l e 13.

A v e r a g e b o d y c o n s t i t u e n t s o f r a t s d u r i n g th e p e r i o d of
w e ig h t lo s s .
Diet of Rats

Body
Constit­
uents

P red icted
Low
High
Sample F Value
Carb o - C arbo­ °
F Value
Wheat
Rats
hydrate hydrate
5%.
1%
Diet C Diet D
No.

L.S.D.
5%

1%

F re s h Basis
Fat

16.40

8.40

8.40

56

15.19
**

3.17

5.01

3.33

4.45

59.30

63.90

64.00

56

6.23

3.17

5.01

3.01

4.02

17.63

20.26

20.22

56

9.18
*'i>
*-p

3.17

5.01

1.08

1.45

3.84

4.54

4.47

42

8.03

3.23

5.18

0.44

0.59

(%)
M oisture
(%)
P ro ten
(%)
Ash
(%)

F a t-F r e :e B asis
Water

70.70

69.69

69.80

56

1.72

3.17

5.01

--

21.00

22.20

22.13

56

1.60

3.17

5.01

--

4.57

5.05

4.88

42

2.16

3.23

5.18

(%)
P ro te in
(%)
Ash
(%)

Highly significant.

--

—”

.(

.

77
fo r the two diets were s im ila r (Figure 1 6).

The loss of weight of

the ra ts on the low -carbohydrate diet during the f i r s t four weeks
was g r e a t e r than that of the ra ts on the high-carbohydrate diet; while
during the la s t four weeks, the re v e rs e was the case.

These resu lts

indicated tjhat when rats are placed on a diet r e s tr ic te d to 12 calories
p e r day, g r e a te r weight reduction will occur on a low-carbohydrate
diet during the p e rio d when the animals are being reduced to what
may be considered " n o r m a l " fat content.

However, when the rats

were kept on the highly r e s tr ic te d diet f o r a longer period of time,
the rats w ere reduced below " n o r m a l " fat content, and both the low
and high carbohydrate diets re su lte d in sim ilar total weight losses.
Although the salt content of the two diets differed, the rats on each
diet receiv ed the sajne amount of salt daily and could be considered
to be in eq u ilib riu m with re s p e c t to salt.

The re s u lts obtained w ere

in ag reem en t with those of Anderson (2), who reported that over-all
weight lo s s e s were s im ila r on low- and high-carbohydrate diets that
contained the sam e amount of salt and furnished the same number of
calo ries, but that when the amount of sa lt in the high-carbohydrate
diet was in creased , less , weight reduction resulted.

Body composition.

The fat content of the r a t c a rc a ss e s d e ­

cre a s e d steadily throughout the time the rats were on the reduction

F ig u re

16.

R e g r e s s i o n of w e ig h t l o s s o n t i m e d u r i n g p e r i o d of w e i g h t l o s s .

5 ° Low carbohydrate diet
100

y = 13.15 + 9.14X
S.E. = 11.42

80

Weight

Loss

in G rams

High carbohydrate diet

y = 8.89 + 8.92X
S.E. = 14.31

60

o

A

40

20

oL

4~~
T i m e in W e e k s

oo

79
diets (Figures 17 and 18).

No significant differences were found b e ­

tween the fa t content of the r a ts on the two different diets (Table 13).
There was a highly significant co rrelatio n between fat loss and body
weight lo s s of the r a ts during the weight-reduction p erio d for both
groups of animals (Table 14).
The m oisture content of the r a t body in creased during the r e ­
ducing period, and the rate of in crease was s im ila r fo r the rats on
both the low -carbohydrate and high-carbohydrate diets (Figure 19).
The m o istu re contents of the r a t c a r c a s s e s on the r e s tr ic te d diets
were significantly higher than those on the control wheat diet when
the m o istu re content was determined on the f r e s h basis (Table 13).
However, when the m oisture content was calculated on a f r e s h fa tfre e b a s is , there were no significant differences between the diets
(Table 13).

These resu lts indicate that the ra ts placed on the low-

and high-carbohydrate diets tended to replace the fat lo s t during the
reducing p erio d with w ater.
*•

.

The p rotein content calculated on the f r e s h b asis showed a
significant difference between the rats on the wheat diet and those on
the reducing diets (Table 13).

However, the protein content of the

ra ts was s im ila r fo r both of the reducing diets and the control wheat
diet when it was calculated on the f r e s h fa t-fre e b asis.

When the

F i g u r e 17.

R e g r e s s i o n of f a t on t i m e d u r i n g p e r i o d of w e i g h t l o s s .

Low Carbohydrate Diet

y = 18.5 - 2 .OX
S.E. = 3.6

A
—

5a

High Carbohydrate Diet

y = 16.3 - 1.6X
S.E. = 4.6

Body

Fat

16

Percent

12 I-

A

■
3*

\

\

NO

A
o
l l

4

o

\

6
Time in Weeks

\

s

8
A

8

\
\

10

00

o

81

F ig u re 18.

R egression of weight loss on fat content during
period of weight loss.

— -j a

Low Carbohydrate Diet

8.89 + 8.92X
S.E. = 14.30

High Carbohydrate Diet

13.15 + 9.14X
S.E. = 11.40

Weight

Loss

140

00

60

20
01

14
P e r c e n t Bodyi<F a t

82
T a b l e 14.

C o r r e l a t i o n c o e f f i c i e n t s of s o m e b o d y c o n s t i t u e n t s d u r i n g
t h e p e r i o d of w e i g h t l o s s .

V ariables

Weight
content
Low
High

Number
of
O b s e r­
vations

Degrees
of
F reedom

Sample
Value
of r

P re d ic te d
r Value
5%

1%

loss, and body
of fat
carbohydrate diet
carbohydrate diet

19
19

17
17

- 0.753**
-0.756**

0.456
0.456

0.575
0.575

Time on diet and body
fat content
Low carbohydrate diet
High carbohydrate diet

19
19

17
17

-0.58 0**
-0.668**

0.456
0.456

0.575
0.575

Time on diet and body
protein content
Low carbohydrate diet
High carbohydrate diet

19
19

17
17

-0.691**
0.456*

0.456
0.456

0.575
0.575

Time on diet and m o is ­
tu re content of body
Low carbohydrate diet
High carbohydrate diet

19
19

17
17

0.738**
0.59**

0.456
0.456

0.575
0.575

Time on diet and body
content of ash
Low carbohydrate diet
High carbohydrate diet

14
14

12
12

0.7 07**
0.165

0.532
0.532

0.661
0.661

* Significant.
** Highly significant.

A

83

F ig u re

19.

‘R e g r e s s i o n of m o i s t u r e

5 ^

on tim e d u rin g re d u c in g p e rio d .

Low Carbohydrate Diet

74
—

High Carbohydrate Diet

70

A
o
o

66

Percent

Body

Moisture

O
A

62

58
A

o

54

.o
4

5

J______L____
6 . 7

T i m e in W e e k s

84
protein, content was calculated on a f r e s h weight basis, it in c re ased
proportionately throughout the period of weight loss on both reducing
diets (Figure 20); th ere was not a significant difference between the
slopes of the curves.

When the data for the p ro tein content were

calculated on a f r e s h f a t- f r e e b asis during the reducing period, there
was an in c re ase of protein up to the fourth week, then a gradual
re tu rn to the average at the end of the experim ent (Table 12 and
F igure 21).
Rats on reducing diets showed a tendency to in c re a se in ash
&
content the longer they rem ained on the reducing diet (Figure 22).
No significant difference between ash content of rats on the highcarbohydrate diet and those on the low -carbohydrate diet was found
(Table 13).

When the ash content was calculated on a f a t- f r e e b asis,

the in c re a s e in ash content became m o re apparent, and a significant
difference between the r a ts and reducing diet and norm al diet was
shown (Table 13).

This indicated that th ere was little loss of ash,

if .any, when the r a ts were put on the reducing diets.

Blood constituents.

The blood cholesterol of the ra ts on the

control wheat diet continued to in crease with age (Figure 23).

The

average concentration of blood cholesterol for the rats during this
p erio d was 74.8 m illig ram s p e r 100 m illilite rs (Table 16), as compared

85

F i g u r e 20.

26

R e g r e s s i o n of p r o t e i n on t i m e d u r i n g p e r i o d of
w e ig h t lo s s .

Low Carbohydrate Diet

y = 16.93 + 0.66X
S.E. = 1.92

High Carbohydrate Diet

y = 17.6X + 0.5IX
S.E. s 2.48
A

24

Percent

Body

P ro tein

o

T im e in W eeks

o

l

F i g u r e 21 .

P r o t e i n c h a n g e s ( f a t - f r e e b a s i s ) d u r i n g p e r i o d of w e i g h t l o s s .

- — •— -

Low Carbohydrate Diet

------------ ; o High Carbohydrate Diet

Percent

Body

P ro tein

------------,X Wheat

24
o\

22 P

5
Time in Weeks

...J_
6

-L _ _ _ _ _ _ _ _ _ _ L _
7

£

F i g u r e 22.

R e g r e s s i o n of a s h on t i m e d u r i n g p e r i o d of w e i g h t l o s s .

Ash

Low Carbohydrate Diet

3.54 + 0.24X
S.E. = 0.59

A High Carbohydrate Diet

> I>

Percent

Body

4.33 + 0.04
S.E. = 0.46

4 -

1

2

3

4
T im e in W eeks

5

6

7

oo

-4

F ig u r e 23,

R e g r e s s i o n of c h o l e s t e r o l on t i m e d u r i n g p e r i o d of w e ig h t l o s s .
-p A High.Carbohydrate Diet
;> X Wheat Diet
-jo

100 Ml. of Serum

80

per

100

60

y = 33.35 + 4..54X
S .E . = 11.89

y » 54.11 + 5.20
S . E . = 17.01

Low Carbohydrate Diet
y - 31.68 + 5.24X
S.E . = 8.65

x
.

x

X

A -'

•zT"
A

Mg. Cholesterol

A

X

X

40

„

2

. L

3

00
00

T im e in W eeks

89
T a b le

15.

C h o l e s t e r o l , p y r u v i c a c i d , a n d p o t a s s i u m c o n t e n t of b lo o d
of r a t s d u r i n g t h e p e r i o d of w e i g h t l o s s .
Week

A
C holesterol
(mg/100 ml)

60.8

Py ru v ic acid
( m g /100 ml)

1.4

P o ta s s iu m
(mg/100 ml)

. 170

1

2

3

Diet

Diet

Diet

C

D

45.8 50.7

2.2

214

2.1

173

A

C

79.5 46.7

1.7

158

1.7

172

D

A

34.3

47.8

1.5

1.8

180

179

C

D

45.5 38.1

1.6

183

2.0

182

90
T a b l e 15 (C o n tin u e d )

Week
. 4 .

5

6

7

Diet

Diet

Diet

Diet

A

C

D

64.6

56.9

45.4

1.4

1.6

1.6

171

--

. 167

182

• A

C

D

72.0

55.5

59.1

1.4

1.2

1.4

184

190

170

A

C

103.9 63.8

1.5

193

1.7

199

D

A

C

D

69.9

90.0

58.6

62.1

1.6

1.1

1.6

1.6

200

195

173

192

A

91
T a b l e 16.

A n a l y s i s of v a r i a n c e of b l o o d c o n s t i t u e n t s o f r a t s d u r i n g
th e p e r i o d of w e i g h t l o s s .

Diet
A

•
Choles­
te ro l
(mg/100
ml)

Diet
D

P red icted
Value
of F
5%

'1 %

(av.)

(av.)

(av.)

74.80

53.80

51.41

41

9 •5**

3.25

5.21

1.6

1.60

40

1.4

3.25

5.21

41

5.97**

3.25

5.21

P yruvic
1.5
acid (m g/
100 ml)
P o ta s­
sium
(ppm)

Diet
C

No.
of
Sample
ObValue
serof F
vations

178.70 186.60 182.20

** Highly significant.

L.S.D.
5%

1%

12.00

16.00

2.49

3.33

92
to 69.8 during the gaining period.

The same ra te of in c re a s e was found

to be tru e for the r a ts that.w ere fed the two r e s tr ic te d diets (Figure 23).
The average concentration of cholesterol in the blood of the r a t s fed the
r e s tr ic te d low -carbohydrate jdiet w a s ,53.8 m illig ra m s and 51.36 m illig ram s fo r the r e s t r i c t e d high^carb'ohydrate diet.

The difference in con­

centration of cho lestero l between the n o rm al fed r a t s and the r e ­
stric te d ones was found to be highly significant (Table

16).

The difference between the two r e s tr ic te d diets was found to be not
significant.

This indicated that the percentage of fa t in the diet did

not have any effect on the cholesterol concentration in the blood.
However, re s tr ic tin g the caloric intake low ered the cholesterol concentation in the blood.

This ag rees with the work of Bose (14),

who attrib uted this to be the effect of hunger.

The data obtained

showed that during the reducing period, the concentration of blood
cho lestero l was lowered.

This is in conflict with the work of P o in ­

dexter and Brunger (83), who rep o rted that the cho lesterol content of
the p la sm a was not a lte re d by reduction in weight.
There was a tendency fo r the amount of pyruvic acid in' the
blood to d ecrea se during the p erio d that the rats were on the lowcalo rie diets (Figure 24).

However, no significant c o rre la tio n was

found to exist between age and pyruvic acid concentration in the

R e g r e s s i o n of p y r u v i c a c i d on t i m e d u r i n g p e r i o d of w e i g h t l o s s .

X

2.4

•—

Low Carbohydrate Diet

195.99 - 2.92X
S.E. = 21.40

Wheat

157.14 + 5.41X
S.E.
11.69

Hi gh Carbohydrate Diet

190.89 + 2.99X
S.E. a 22.2

2.2
2. 0

Acid

per

100 Ml. of Blood

F i g u r e 24.

Mg. Pyruvic

x

T im e in W eeks

vO
w

94
blood (Table 17).

Rats fed the control wheat diet ad libitum had an

average of 1.45 m illig ra m s pyruvic acid p er 100 m illilite r s in the
blood (Table 15).

No significant difference was found between the

blood pyruvic acid of r a ts fed ad libitum and that of r a ts given the
low -calo rie diets.

There was an average of 1.60 m illig ra m s p er

cent of pyruvic acid in the blood of r a ts in both the high- and lowc a r b o h y d r a te - r e s itr ic te d diets (Table 16).

It appeared that the con­

centration of pyruvic acid in the blood of r a ts was not affected by age,
fat content of the diet, n o r by the num ber of calo ries consumed (Table
17), and that burning body fat during weight loss did not have an e f­
fect on the pyruvic acid concentration.
The concentration cf potassium in the blood of the r a t s was
179, 187, and 182 p a rts p e r million, respectively, for the control
wheat, low -carbohydrate and high-carbohydrate diets (Table 16).

There

was an indication that the potassium concentration in the blood of the
high-carbohydrate fed r a t s and the wheat-fed ra ts in c re a s e d with the
length of tim e on the diet (Figure 25).

However, none of these c o r ­

relatio n s was found to be significant (Table 17).

The ra ts fed the

control wheat diet m aintained a blood concentration of potassium
(178.7 ppm), which was significantly lower than the average blood
potassium of r a ts on the r e s tr ic te d diets (Table 16).

No significant

95
Table 17.

C o rrelatio n coefficient of c ertain blood constituents and
time of experim ent for r a ts on low calorie diets.

Variable sk
1

No. of
O b se r­
vations

D egrees
of
F reedom

Sample
Value
of r

-Predicted
Value
of r
5%

1%

0.532
0.553
0.532

0.661
0.684
0.661

Time on diet and blood
cholesterol
Wheat diet
Low carbohydrate diet
High carbohydrate diet

14
13
14

12
11
12

Time on diet and blood
pyruvic acid
Wheat diet
Low carbohydrate diet
High carbohydrate diet

14
14
13

12
12
11

-0,463
-0.558*
-0.409

0.532
0.532
0.553

0,661
0.661
0.684

Time on diet and blood
potassium
Wheat diet
Low carbohydrate diet
High carbohydrate diet

14
13
13

12
11
11

0.744**
-0,283
0.247

0.532
0.553
0.553

0.661
0.684
0.684

* Significant.
** Highly significant.

0.55 0*
0.895**
0.764**

25 .

R e g r e s s i o n »of p o t a s s i u m o n t i m e d u r i n g p e r i o d o f w e ig h t l o s s .

o Low Carbohydrate Diet

220

y = 196.00 - 2.92X
S.E. = 21.40

- ) X Wheat. Diet

y a 157.14 + 5.41X
S.E. = 11.68

■j 4 High Carbohydrate Diet

y * 170.90 + 2.99X
S.E. = 22.20

0

200

X

APA

o

XX

Parts

Per

Million

Potassium

in Blood

F ig u re

180

><

X

160
150

4
Time in Weeks

I
5
vO

O'

97
difference was found between the concentrations of potassium in the blood
of r a t s on the high- o r low -carbohydrate diet (Table 16).

Ju st as the

data obtained during the weight-gain period showed that th e re was a
relation between the blood p otassium and body content of fat, the data
obtained during the w eight-loss p erio d indicated a relation-betw een
the amount of potassium in the blood and the amount of fat burned
in the body.

This suggests that p otassium had a ro le during the

p ro c e s s of f a t deposit and fat burning in the body.

This also sug­

gests that p otassium has a role in f a t metabolism as well as in c a r ­
bohydrate m etab o lism as rep o rte d by many investigators (33, 85,
63, 39).
Since, at the end of the eight-week period, the weight of the
r a ts on the r e s tr ic te d diej:s was 3 6 p e r cent below the weight of the
control r a ts and below what is considered the n o rm al f o r th e ir age
(60), and since the c a r c a s s content of fat reached an average concen­
tratio n of 3.4 p e r cent, which was fa r below that of the control rats
(16.4 p e r cent) and that re p o rte d in the lite r a tu r e as the norm al fat
content of ra ts (24, 28, 47), it would appear that the r e s tr ic te d diets
used resu lted in starvation.

This severe deprivation may have masked

the differences effected by the two r e s tr ic te d diets which might have
been apparent if l e s s sev ere calorie deprivation had been imposed on

the anim als.

Starvation is also indicated by the fact that the blood

cholesterol values were found to be low er in the reduced animals
than in those of the control and low er than those re p o rte d as the
norm al f o r the blood of r a ts ,

Man and Gildea (66) found that s t a r v ­

ation caused a d ecrea se in the concentration of blood cholesterol.
P oindexter (83) and oth ers (111) rep o rte d that th e re was a slight
in c re a s e of blood cholesterol values during the initial period of weight
reduction.

This was followed by a re tu r n to no rm al values.

In this

study, the blood cholestero l values d ec re a se d during the initial period
of weight reduction and rem ained lower throughout the entire e x p e r i­
ment than those of the control ra ts on the wheat diet.

The blood

p otassium values of the ra ts on the r e s tr ic te d diets also were found
to be lower than those of the control r a t s - - a phenomenon which Mellinghoff (68) had observed during starvation.

SUMMARY AND CONCLUSION

The influence of diets of different composition on c ertain body
and blood components and on the ra te of weight gain and weight loss
of r a ts was studied.

One hundred and fo rty -fo u r m ature female r a ts ,

approxim ately 120 days of age, were used in the experiment.

In the

f i r s t period, o n e-th ird of the rats were fed a wheat diet ad libitum;
the remaining rats were fed a corn diet, ad libitum, in an attempt
to produce obese anim als.

Both groups of r a ts gained weight through­

out a p erio d of approxim ately 140 days.

No significant differences

were found between the final weight of the r a ts on the two diets,
indicating that obesity, in te rp re te d as e x c e s s body weight, did not
o ccu r as had been expected in the ra ts fed the corn diet.
The protein, fat, m o istu re, and ash contents of the r a t c a r ­
c a sse s were determ ined at periodic interv als.

Of these components,

the only f a c to r that v a rie d g reatly during weight-gain period was the
fat.

The average fa t content of the r a ts fed the control wheat diet

was 12.8 p e r cent, and that of the ra ts fed on the c o m diet was 17.2
p e r cent.

The protein, m o istu re, and ash contents of the body were

found to be relatively stable when calculated on a fa t-fre e basis.

100
However, when the components were calculated on a f r e s h basis, an
in c re ase in fa t content was asso ciated with a decrease in the m o is ­
tu re content.
Body analyses indicated that the weight in crease of r a ts b e ­
tween the ages of 120 and 2 60 days rep resen te d adult growth and
was not a deposition of adipose tissue as believed by Spray (101),
since no co rre latio n .between age or body weight and body composition
was found.
The blqod cholesterol of r a ts fed ad libitum was affected by
diet, age, and body fat content.

Rats fed the corn diet had lower

blood cholesterol values than the r a ts fed the wheat diet.

O lder

ra ts also had higher cholesterol concentrations than younger r a ts ,
and r a ts that had high body fat content had lower blood cholesterol
values than the ra ts th at had low fat content.
Blood p otassium was affected by the type of diet and the
amount of fat in the body.

Corn-fed rats had higher blood potassium

values than the rats fe d the wheat diet, and the blood potassium v alues tended to in c re a se with an in crease in body fat.
N either age nor diet was found to have any effect on the
blood pyruvic acid concentration.

Body fa t content was the only

fa c to r that was found to have a relation to the blood pyruvic acid

101
concentration.

The blood pyruvic acid content in c re a se d with the

increase in the fat content of the body.
At the end of the weight-gaining p erio d the rats fed the corn
diet w ere p a ire d according to weight.

One group was fed a high-

carbohydrate diet and the other a low -carbohydrate diet.
were fed 12 c alo ries p e r day.

Both groups

The control rats were continued on

the wheat diet fed ad libitum.
No difference was noticed between the effect of the highcarbohydrate and the low -carbohydrate r e s tr ic te d diet on the rate of
weight lo ss of the ra ts , and the total lo ss in weight was approxim ately
the same f o r rats on the two diets.

The two r e s tr ic te d diets had

n early the same effect on the body composition of the rats.

Great

loss of body fat was accompanied by little change in the w ater and
protein content calculated on a f a t- f r e e ba sis, and no change in the
ash content was observed.
The r a ts fed the two r e s tr ic te d diets had lower blood ch o les­
te ro l values than the ra ts fed the control wheat diet.

No signifi­

cant difference between the effect of the two r e s tr ic te d diets was
noticed.
Rats fed the r e s tr ic te d diets and the control wheat diets had
n e a rly the same, blood pyruvic acid values.

With both r e s tr ic te d

102
diets an in c re a se in the blood potassium was observed.

The rats

fed the r e s tr ic te d diets showed higher potassium values than those
fed the control wheat diet.

LITERATURE CITED

(1952) Amen, H. C.
The blood seru m cho lestero l of over
weight college women on a controlled weight reduction
diet.
Unpublished Thesis. Michigan State College.
(1944) Anderson, A. B. Loss of "Weight in Obese Patients on
Sub maintenance Diets and the Effect of Variation in the
Ratio of Carbohydrate to F a t in the Diet. Quart. J.
Med. 13: 27.
(1950) Association of official ag ricu ltu re chem ists, official
methods of analysis, 7th edition.
(1938)

B'achmann, G., J. Haldi, W.
Wynn, C. E nsor. TheEffect
of High Glucose and a High F ru cto se Diet onthe Body
Weighty and on the F a t Glycogen and Nitrogen Content
..of the> L iv e r and Body of the Albino Rat. J. Nut. 16 :
229.

(1950) Bargoni, N. Acide Pyruvique et Reticulocytes dans les
Sang des Rats N ormaux et Cancereaux. E xcerpta Medica
vol. 3, no. 1, Sect. 2: 3223.
(1941)

Bauer, Julius. Obesity, its
Pathogenesis, Etiology and
T reatm ent. Arch. Int. Med. 67: 9 6 8 .

(1935) B a r te ls , E. C., B. Blum.
Lab. Clin. Med. 20: 401.

Water Study in Obesity.

J.

(1907) Benedict, F. G., R. D. Milner. Experim ents on the
M etabolism of M atter and Energy in Human Body.
USDA Office Exp. Sta. Bull. 175.

9.

(1939) Benetato, G., P . Cuirdarui. Influence of Age on Blood
P o tassiu m .
Compt. Rend. Soc. Biol. 132: 175. Chem.
A bstract.

104
10.

(1943) Best, C. H., N. B. Taylor.
The Physiological B asis of
Medical P r a c tic e .
The Williams and Wilkins Company.
B altim ore, Page 100 5.

11.

(1935) Blotner, H. Blood F a t Tolerance Tests in Malnutrition
and Obestity. Arch. Int. Med. 55: 121.

12.

(1932) Bloor, W. R. Diet and the Blood Lipids.
Chem. 95: 633.

13.

J. Biol.

(1922) Boothby, W. M., I. Sandlford. Summ ary of the basal
m etabolism data on 8614 subjects with especial reference
to the norm al standards f o r the estim ation of the basal
metabolic rate. J. Biol. Chem. 54: 783.

14.

(1946) Bose, J. P ., U. N. De, P . Mukerjee. A P r e lim in a r y
Study of the Biochemical Changes in Starvation, Indian
J. Med. R esearch 34: 143 (Biol. Abst. 21: 16854).

15.

(1934) B ru g er, M., C. A. Poindexter.
Relation of P la s m a
C holesterol to Obesity and to some of the Complicating
degenerative D iseases. Arch. Int. Med. 53: 423.

16.

(1932) B ru ger, M., I. Somach.
The Diurnal Variations of the
C holesterol content of the Blood. J. Biol. Chem. 97: 23.

17.

(1947) Carlson, A. J., F . Hoelzel. Growth and Longevity of
Rats Fed Omnivarous and Vegetarian Diets. J. Nut.
34: 81.

18.

(1952) Cederquist, D. C., W. D. Brew er, R. M. Beegle, A. N.
Wagoner, D. Dunsing, M. A. Ohlson. Weight Reduction
on L o w -F at and Low-Carbohydrate Diets.
1. Clinical
Results and Energy Metabolism. J. Am. Diet. Assoc.
28: 113.

19.

(1952) Cederquist, D. C., W. D. B rew er.

20.

(1938) C hristian, H. A. in O s ie r, W. The P rincip le and P r a c ­
tice of Medicine. Ed. 13. New York: D. AppletonCentury Co., Inc.

P e r s o n a l Communication.

A

105
21.

(1931) Chanutin. A.
The Influence of Growth on a Number of
Constituents of the White Rat. J. Biol. Chem. 93: 31.

22.

(1936) Cook, R. P.
Cholesterol Feeding and F a t Metabolism.
Biochem. J. 30: 1630.

23.

(1944) Deuel, H. J., J r . , E. Movitt, L. Hallman, J. Mattson.
Studies of the Comparative Nutritive Value of F a ts . I.
Growth Rate and Efficiency of Conversion of Various
Diets to Tissues.
J. Nut. 27: 107.

24.

(1944) Deuel, H. J., J r . , L. F. Hallman, E. Movitt, F . H. M att­
son, E. Wu. Studies of the Comparative Nutritive
Value of F ats.
J. Nut. 27: 335.

25.

(1952) De Michele, G., D. F ra n c is c is .
Lactic and P yruvic
Acid in the Blood of P atien ts with Pulm onary Tubercu­
lo sis, in Connection with R esp irato ry Deficiency. Exc e rp ta Medica Vol. 5, No. 2, Sect. 2: 922.

26.

(1917) Denis, W. Cholesterol in Human Blood under Pathological
Conditions. J. Biol. Chem. 29: 93.

27.

(1936) Dienst, C.
The Importance of the Sodium -Potassium
Antagonism fo r Water Metabolism. Arch. Expt. Path.
Pharm akol. 182: 5 67.

28.

(190 6) Donaldson, H. H. A Comparison of the White Rate
Man in Respect to the Growth of the
n tire Body.
A nniversary Vol. New York.

with
Boas

29.

(1936) Dublin, L. I., A. J. Lotka.
The Roland P re s s. Co.

Length of Life. New York:

30.

(1936) Elliott, A. H., F. R. Nuzum, Cholesterol Content of
Whole Blood in Patients With A r te ria l Hypertension.
Arch. Int. Med. 57: 63.

31.

(19 31) Evans,
. A., J. M. Strang.
The Treatm ent of Obesity
with Low Caloric Diets. J. Am. Med. Assoc. 97: 10 63.

106
32.

(1939) Fenn, W. O. Rate of P o tassiu m L ib erated from Muscles
During Activity. Am. J. Physiol. 127: 35 6.

33.

(1940) Fenn, W. O. Role of P o ta ssiu m in Physiological P r o c ­
e s s e s . Physiol. Rev. 20: 377.

34.

(1913) F e r r y , E. L.
The Rate of Growth of the Albino Rat.
Anat. Record 7: 433.

35.

(1945) Friedem ann, T. E., G. E. Haugen, T. C. Kmiaciak.
The
Level of Pyruvic and Lactic Acids and the L ac tic-P y ru v ic
Ratio in the Blood of Human Subjects.
The Effect of
Food, Light Muscular Activity and Anoxia at Hig"h A lti­
tude. Ji., Biol, Chem. 157: 67 3.
V

36.

37.

(1923) F isk , E.- L. Health Building and Life
York: 'The Macmillan Co.

extension.

New

(1950) Foldes, F. F ., B. C. Wilson. Determination of Chol­
e stero l. Adaptation of Schoenheimer and S p erry 's
Method to P hotoelectric Instrum ents. Anyl. Chem. 22:
1210.

38.

(1913) G ardner, J. A., P . E. Landen.
The Cholesterol Con­
tent of the Tissues of Cats Under Various Dietetic
Conditions and During Inanination. Biochem. J. 7: 576.

39.

(1950) Gardner, L., N. Talbot, C. Cook, H. Berman, C. Uribe.
Effect of P o tassiu m Deficiency on Carbohydrate Metab­
olism . J. Lab. and Clin. Med. 35: 592.

40.

(1948) Goldsmith, G. A.
The Blood Lactate Pyruvate Relation­
ship in Various Physiological and Pathological States.
Am. J. Med. Sci. 215: 182.

41.

(1943) Gough, N. Effect of Diet on the Concentration of Chol­
e s te ro l in Blood and Bile. Brit. Med. J. 2: 390.

42.

(1938) Haarmann, W., E. Schroeder.
Sugar. Biochem. Z. 296: 35.

Conversion of F a t into

107
43.

(1927) Hagedorn, H. C., C. Holten, H. Johansen.
The Pathology
of Metabolism in Obesity. Arch. Int. Med. 40: 30.

44.

(1936) Hanssen, P e r .
The T reatm en t of Obesity by Diet R e la ­
tively P o o r in Carbohydrates. Acta Med. Scand. 88: 97.

45.

(1948) H arte, R. A., J. J. T ra v e rs , P. Sarich.
oric Intake in Rats.
J. Nut. 36: 667.

46.

(1942) Hasting, A. B., J. M. Buchanan.
The Role of In trac ellu lar
Cations on L iv e r Glycogen F o rm atio n in Vitro. P ro c .
Nat. Acad. Sci. 28: 478.

47..

(1917) Hatai, S. Changes in the Composition of the Entire
Body of the Albino Rat During the Life Span. Am. J.
Anat. 21: 23.

48.

(1949) Hatz, F. Influence of the A dm inistration of Natural
Amino Acids on the Blood Content of F r e e Alanine and
P yruvic Acid in the Rabbit. E x cerp ta Medica, Vol. 2,
No. 2, Sect. 2: 3583.

49.

(1940) Hetherington, A. W. Obesity in the Rat Following the
Injection of Chrouic Acid into the Hypophysis. Endo­
crinology 26: 264.

50.

(1940) Howard, C. P . , E. S. Mills. Obesity. C hristian, H. A.
Oxford Medicine. New York. Oxford University P r e s s .
Vol. 4: 195.

51.

(1951) Hunter, F. R. O bservations on the Use of the Flam e
P hotom eter f o r Analysis of Blood. J. Biol. Chem. 192:
701.

52.

(1934) Hurxthal, L. M. Blood Cholesterol and Hypometabolism.
Obesity and Miscellaneous Conditions. Arch. Int.~ Med.
53: 825.

Voluntary C a l­

it

53.

(1944) Hutchinsob, J. C. D.
The Effect of Nutrition on the
C a rc a ss ‘Composition of the Rabbit. B rit. J. Nut. 1:
219.

,A

108
54.

(1949) Hutchinson, J. C. D., E. G. L. Baker. Nutrition of
Domestic R ab b its--T h ree Variations in C a rc a ss Com­
position of Rabbits R eared f o r Meat. B rit. J. Nut. 3:
12.

55.

(1952) Jolliffe, N. Reduce and Stay Reduce.
Inc., New York. Page 1.

Simon and Schuster

56.

(1952) Jubb, A. C.

57.

(1939) Keizo, Yosio. Influence of Nutrition on the Action of
Adrenaline. III. The P o ta ssiu m /C a lc iu m Quotient in
the Blood on Different Diets. J. Biochem. (Japan) 29:
167 (Chem. Abst. 33: 46447).

58.

(1950) Keys, A., O. Mickelsen, E. M iller, E. Hayes, R. Todd.
The Concentration of C holesterol in the Blood Serum of
Norm al Man and its Relation to Age. J. Clin. Invest.
29: 1347.

P e r s o n a l Communication.

59.

(1935) K irk, E., I. H. Page, W. H. Lewis, W. R. Thompson,
D. D. VanSlyke. P la s m a Lipids of N orm al Men at .
Different Ages.
J. Biol. Chem. I l l : 613.

60.

(1915) King, H. D.
The Growth and V ariability in Body Weight
of the Albino Rat. Anat. Record 9: 751.

61.

(1950) K om erup, V. Concentrations of Cholesterol, Total F at
and Phospholipid in Serum of Normal Man. Report of a
Study with Special Reference to Sex, Age and Constitu­
tional Type. Arch. Int. Med. 85: 398.

62.

(1939) L arson , P . S., G. B rew er. Mechanism of the D epression
of Serum P o tassiu m by Anesthetics. J. P harm acol. 67:
147.

63.

(1940) Lasnitzki, A. P o ta ssiu m and Carbohydrate Metabolism.
N ature 14 6: 99.

64.

(1917) Luden, G. Studies on Cholesterol. IV. Experiments
Concerning the Relation of Diet, the Blood Cholesterol
and the "Lyphoid D efense."
J. Lab. Clin. Med. 3: 141.

109
65.

(1932) Lyon, D. M., D. M. Dunlop.
The Treatm ent of Obesity.
A Comparison of the Effect of Diet and of Thyroid E x ­
tra c t.
Quart. J. Med. (New Series) 1: 331.

66.

(1936) Man, E., E. Gildea.
J. Chem. Invest. 15:

Serum Lipoids in Malnutrition.
20 3.

67.

(1937) Man, E. B., E. F. Gildea. Variations
Normal Subjects.
J. Biol. Chem. 119:

68.

(1949) Mellinghoff, K. P o tassiu m and Calcium Content of
Htlrnan Blood During Prolonged Fasting.
Deut. Arch.
Klin. Med. 194:277.

in Lipem ia of
769.

69 .

(1951) MoUge, ;C. C. Glucose, L actic Acid and Pyruvic Acid
at" S a Level and in Higher Altitude.
x cerp ta Medica
Vol. 4, No. 3, Sect. 2: 1368.

70.

(1950) Meyer, J. H., R. R. Grunert,
M. Zepplin, R. H. G rum m e r, G. Bohstedt, P. H. P hillips.
Effect of Dietary
Levels of Sodium and P o tassiu m on Growth and on
Concentrations in Blood P la s m a and Tissues of White
Rats. Am. J. Physiol. 162: 182.

71.

(1941) Monnier, M., A. F archadi, A. Manlbetsch. Blood
e s te ro l in the Rat. Arch. Sci., Phys. Nat. 23.

72.

(1923) Moulton, C. R. The Chemical Development of the Body.
J. Biol. Chem. 57: 79.

73.

(1919) M urray, J.

74.

(1922) M urray, J. A.
The Chemical Composition of
Bodies.
J. Agr. Sc. 12:103.

75.

(1930) Newburgh, L. H., M. W. Johnston.
J. Clin. Invest. 8: 197.

76.

(1933) Newburgh, L. H., F. H. Lashm et.
The Importance of
Dealing Quantitatively with Water in the Study of Disease.
Am. J. Med. Sci. 186: 461.

A.Meat Production.

Chol­

J. of Agr. Sc. 9: 174.
Animal

The Nature of Obesity.

110
77.

(1942) Newburgh, L. M.

Obesity.

Arch. Int. Med. 70: 1033.

78.

(1946) Nhavi, N. G., O. H. Patw ardham . Level of F a t Intake
and Composition of Serum Lipoids. Indian J. Med. Re­
s e a rc h 34: 257.

79.

(1947) Overmand, R. R., A. K. Davis.
The Application of Flame
P hoto m etry to Sodium and P o ta ssiu m Determinations in
Biological F luids. J. Biol. Chem. 168: 641.

80.

(1952) Palom ba, R., G. Budroni. P o sto p erativ e Variations in
Pyruvic Acid Content of the Blood. E xcerpta Medica
Vol. 5, No. 7, Sect. 2: 3684.

81.

(1949) Pennington, A. W. Obesity in Industry.
and its Solution. Ind. M. 18: 259.

82.

(1943) Pete.rs, J. P ., E. B. Man.
Lipids in N ormal P e rs o n s .

The P roblem

The In terrelatio n s of Serum
J. Clin. Invest. 22: 707.

83.

(1935) Poindexter, C. A., M. B ruger.
Effect of Low-Caloric
Diets and Resultant Loss in Weight on P la s m a C holes­
te ro l in the Obese. Arch. Int. Med. 56: 884.
■/

84.

(1946) Popjak, G. Effect of Feeding Cholesterol Without F a t
on P la s m a Lipids in Rabbits. Biochem. J. 40: 60 8.

85.

(1940) P ulv er, L., F. V e rz a r.
Connection Between Carbohydrate
and P o tassiu m Metabolism in the Y east Cell. Nature
145: 823.

86.

(1942) Rafsky, H. A., B. Newman.
Cholesterol Studies in the
Aged. J, Lab. Clin. Med. 27: 1563.

87.

(1938) Ranson, S. W., F is h e r, C., W. R. Ingram. Adiposity
and Diabetis Mellities in a Monkey with Hypothalamic
Lesions. Endocrinology 23: 175.

88.

(1929) Rony, H., A. J. Levy. Studies on F a t Metabolism.
I.
F a t Tolerance in Obesity. J. Lab. and Clin. Med. 15:
22i;

Ill
89.

(1947) Scheer, B. T., J. F. Codie, H. J. Deuel, J r .
The Effect
of Fat„Lev'^l of the Diet on General Nutrition. III. Weight
L o s s ,-M o rta lity and Recovery in Young Adult Rats,
Maintained On R estricted C alories. J. Nut.
33: 641.

90.

(1947) Scheer, B. T., E. Straub, M. F ields, E. R. M eserve,
C. Hendrick, H. J. Deuel, J r .
The Effect of F a t Level
of the Diet on General Nutrition. IV. The Comparative
Composition of Rats in Relation to Intake of F at and
C alories. J. Nut. 34: 581.

91.

(1934) Schoenheimer, R., W. M. S perry.
A micromethod for the
determ ination of fre e and combined cholesterol.
J.
Biol. Chem. 106 : 745.

92.

(1936) Schube, P. G. Variations in the Blood Cholesterol Over
a Time P eriod . J. Lab. Clin. Med. 22: 280.

93.

(1953) Sebrell, W. H. Nutrition P a s t and F u tu re.
Reviews 11: 65.

Nutrition

94.

(1924) Sherman, H. C., H. L. Cambell. Growth and Reproduc­
tion Upon Simplified Food Supply. IV. Improvement in
Nutrition Resulting F ro m an In creased Proportion of
Milk in Diet. J. Biol. Chem. 60: 5.

95.

(1927) Shope, R. E. Sugar and Cholesterol in the Blood Serum
as Related to
asting. J. Biol. Chem. 7 5: 101.

96.

(1927) Smith, P . E.
The Disabilities Caused by Hypophysectomy and Their R epair. J.A.M.A. 88: 158.

97.

(1950) Smith, E. Blood Pyruvate Levels Following Intravenous
Glucose Injections in Aged Males. Am. J. Med. Sci.
220: 78.

98.

(1945) Sobel, A. E., A. M. Meyer. Improvement in the Schoen­
h e im e r-S p e rry Method for the Determination of F re e
Cholesterol in Human Blood Serum. J. Biol. Chem. 157:
255.

4

112
99.

(1936) Sperry, W. M.
The Relation Between Total and F r e e
C holesterol in Human Blood Serum. J. Biol. Chem. 114:
125.

100.

(1943) Sperry, W. M., F. C. Brand.
The C alo rim etric D e te r ­
mination of Cholesterol.
J. Biol. Chem. 150: 315.

101.

(1949) Spray, C. M.
The Effect of Growth and Development on
the Composition of Mammals. B rit. J. Nut. 3-4: 332.

10 2 .

(1924) Strouse, S.,
of Obesity.
275.

103.

(1941) Starling, E. H. Human Physiology.
Philadelphia. Page 9 8 6 .

104.

(1941) S teiner, A., B. Domanski.
D ietary H ypercholesterolem ia.
A m ; J. Med. Sci. 201: 820.

105.

(1942) Stotz, E., O. A. Besey.
The Blood L actate-P y ru v ate
Relation and its Use in E xperim ental Thiamin Deficiency
in Pigeons.
J. Biol. Chem. 143: 625.

106.

(1949) Taylor, R. M., E. W. McHenry. Pyruvate Curves of
Normal and Obese Subjects Following Ingestion of C a r ­
bohydrates,
Canad. M. A. J. 61: 518.

107.

(1941) Treadwell, C. R., H. C. Eckstein. Sterol Metabolism in
Young Wjbite Rats. II. The Effect of High and Low F a t
Diets oh fthe Cholesterol Metabolism of F o u r Generations
of White R ats.
J. Biol. Chem. 140: 35.

108.

(1950) Tsao, M. U., S. Brown. Pyruvic Acid Determination:
A Micromethod.
J. Lab. and Clin. Med. .35: 320.

109.

(1939) T u rn er, K. B., A. Steiner. A Long Term Study of the
Variation of Serum Cholesterol in Man.
j . Clin. Invest.
18: 45.

110.

(1939) V e rz a r, F., J. C. Smogyi. Connection Between Carbohy­
drate and P o tassiu m Metabolism in Normal and Adrenalectomized Animals. Nature 144: 1014.

C. C. Wang, M. Dye. Studies on Metabolism
II. Basal Metabolism.
Arch. Int. Med. 34:

Lea and F ebig er.

d

113
111.

(1951) Walker, W. J., J. A. Wiel. P la s m a Cholesterol Levels
During Rapid Weight Reduction. Gorgas Hosp. Canal
Zone Circulation 3: 8 64.

112.

(1932) Wilder, R. M.
The Regulation of the Weight of the
Body. Internat. Clin. 1: 30.

113.

(1944) Wynn, W., J. Haldi. F u r th e r Observations on the Water
and F a t Content of Skin and Body of Albino Rat on High
F a t Diet. Am. J. Physiol. 142: 508.

114.

(1941) Wortis, H., R. Goodhart, E. Bueding.
Cocarboxylase,
P y ru v ic Acid and Bisulfite Binding Substances in Child­
ren. Am. J. Dis. Child. 61: 226.

APPENDIX

115
Table 18.

Rat
No.

Data for ra ts fed wheat diet during the period of weight
gain.

N o. of
Weeks
on Diet

O rig ­
inal
Weight

Wt. of
Rat When
Killed

Total
Gain
in
Weight

T otal
F ood
Con­
sumed

96

7

148

178

30

355

95

7

169

206

37

398

94

8

156

191

35

424

93

8

176

200

24

435

92

9

163

173

10

409

90

9

136

170

34

454

89

10

125

180

55

594

88

10

152

221

69

624

87

12

155

198

43

659

86

12

171

224

53

710

85

14'

151

197

46

723

84

14

167

202

35

672

83

16

147

200

53

758

82

16

164

218

54

747

81

18

131

204

73

868

80

18

150 .

222

72

939

79

20

144

197

53

1,271

78

20

164

214

5-

1,076

^ t'i

116
Table

18 ( C o n t i n u e d )

Body Constituents
M oisture
(%)

P ro te in
(%)

Blood Constituents

(%)

Ash
(%)

P o ta s­
sium
(ppm)

F at

Choles­
Pyruvic
Acid
te ro l
( m g /100ml)( m g/100m l

62.8

17.37

13.38

4.26

165.0

3.45

5.7.50

65.6

16.15

12.88

4.18

135.0

1.76

51.34

60.26

19.75

13.67

3.27

195.0

1.22

80.00

61.48

17.61

15.71

3.78

225.0

1.70

86.67

61.5

17.45

14.33

3.87

180.0

2.05

36.50

61.7

■ 17.60

12.72

3.94

192.5

1.84

45.00

61.4

18.01

13.08

3.85

160.0

2.57

39.50

62.85

17.85

11.21

4.00

152.0

2.18

116.67

61.41

18.00

12.55

3.72

172.5

76.25

61.9

18.26

11.73

4.00

142.5

--

63.31

17.92

11.01

4.05

62.81

18.34

11.45

3.95

202.5

62.0

17.99

12.03

4.11

185.0

'61.1

17.57

12.74

4.02

180.0

2.71

80.72

60.8

18.01

13.58

3.85

207.5

2.34

64.17

58.75

16.94

17.68

3.72

157.5

2.59

71.39

64.3

18.87

8.89

3.98

162.5

1.62

82.67

63.5

16.98

10.12

4.07

157.5

2.50

---

1.86

83.75

2.88

73.00
72.29

117
Tab

Rat
No.

19.

D a t a f o r r a t s f e d c o r n d i e t d u r i n g t h e p e r i o d of w e i g h t
gain.

No. oft
W
1
Weeks
on Diet
•n t

•
O ng• a'1l
m
Weight

Wt. oft
O 4. When
iirr
Rat
Killed
.

Total
.
Gam
.

Total
Food

in
Weight

°n
sunned

w +

„

146

7

173

192

19

379

145

7

185'

215

29

376

144

8

169

210

41

406

143

8

174

200

26

417

133

9

163

191

28

459

141

9

160

212

52

479

140

10

170

205

35

536

138

10

164

205

41

509

137

12

158

222

64

612

136

12

171

209

38

597

135

14

166

217

51

724

134

14

175

211

36

625

132

16

161

227

66

736

131

16

178

250

72

856

130

18

163

214

51

788

129

18

186

255

69

993

128

20

175

213

38

1,012

20

178

238

60

1,056

118
T a b l e 19 ( C o n t i n u e d )

Body Constituents

Blood Constituents

(%)

P o ta s­
sium
(ppm)

Pyruvic
Acid
(mg/100
ml)

Choles­
te ro l
( m g /100
ml)

15.91

3.45

177.5

1.28

74.25

17.12

18.07

3.62

225.0

1.90

46.25

59.39

17.41

17.47

3.40

195.0

1.44

57.08

60.67

17.30

16.00

3.62

175.0

2.48

77.92

59.20

16.75

17.61

3.33

--

36.00

61.30

17.35

15.30

3.94

182.5

1.86

46.50

59.55

17.81

15.66

3.96

185.0

2.41

--

56.77

16.20

20.00

3.75

185.0

58.39

17.09

15.86

4.18

187.5

--

84.38

60.12

18.18

14.34

4.15

217.5

3.08

85.67

58.81

17.09

17.41

3.85

205.0

2.92

94.38

58.19

18.00

15.42

3.50

162.5

3.93

33.0

59.65

17.01

15.78

3.90

195.0

2.89

75.0

55.75

15.99

29.81

3.15

200.0

2.77

69.5

58.28

17.16

17.91

3.71

185.0

1.41

80.50

54.61

..,18.18

19.20

3.72

185.0

3.50

74.83

61.32

19.57

11.82

3.90

185.0

1.65

62.09

60.21

;7.85,t
V*S

14.62 '

4.14

182.5

1.44

53.33

Moisture

P ro tein

F at

Ash

( %)

(%)

(%)

60.00

17.57

58.52

--

69.83

Jk

119
T a b l e 20.

D a t a f o r r a t s f e d w h e a t d i e t d u r i n g t h e p e r i o d of w e i g h t
loss.
F ood
Con­
sumed
During
Reducing
Perio d

Rat
No.

No. of
, Weeks
on Diet

O rig ­
inal
Weight

Gain
in
Weight

F ood
Con­
sumed

Weight
at S tart
of R e­
ducing
P e rio d

76

1

168

52

1,250

220

220

25

75

1

136

88

1,614

224

228

44

74

2

141

66

1,631

207

214

144

73

2

148

63

1,478

211

217

153

71

3

123

71

1,272

194

197

153

69

3

178

49

1,391

227

222

158

68

4

158

36

1,111

194

200

193

67

4

160

29

1,211

189

193

220

66

5

138

84

1,336

222'*

232

289

65

5

162

76

1,566

238

246

438

64

6

170

55

1,371

225

230

380

63

6

156

42

1,308

198

202

344

60

7

168

48

1,425

216

221

471

59

7

157

46

1,426

203

201

418

55

8

151

89

1,404

240

240

519

54

8

143

56

1,287

199

200

442

50

8

161

83

1,377

244

230

389

'

Weight
When
Killed

120
T a b l e 20 ( C o n t i n u e d )

•

Blood Constituents
Body Constituents
p

Moisture

P ro te in

(%)

(%)

57.96

Pyruvic
Acid
,
/,
(mg/,1“°
ml)

Choleste ro l
,
,,
<mg/, °°
ml)

F a t (%)

Ash (%)

sium
(ppm)

17.36

17.97

3.36

167.0

58.49

17.58

17.70

•3.34

172.5

1.48

55.5

60.79

17.97

15.13

4.08

162.5

1.40

67.2

60.33

17.80

15.50

3.42

152.5

2.03

54.41

19.67

18.23

4.19

165.0

1.48

46.8

58.53

17.92

*

16.82

4.10

192.5

2.04

48.8

57.10

,.17.76 ‘ ;

17.34

3.87

162.5

1.38

67.3

60.51

16.80

15.70

3.95

180.0

1.40

61.9

57.70

15l2I

19.91

2.94

197.5

1.70

69.9

58.30

17.82

17.17

3.73

170.0

1.12

74.2

61.95

18.22

13.35

4.48

192.5

1.24

' 118.2

60.04

18.11

15.03

3.90

192.5

1.81

89.6

61.55

18.06

13.56

4.39

187.5

1.07

91.5

64.09

15.92

12.87

3.94

202.5

1.14

88.5

58.60

18.69

14.33

57.89

17.33

18.66

61.44

18.32

13.57

57.48

16.25

21.35

76.1

'

91.8

121
T a b l e 21 .

D ata fo r r a t s fed lo w -c a rb o h y d ra te d iet during the p e rio d
of w e i g h t l o s s .
F ood
Con­
sumed
During
Reducing
P e rio d

Rat
No.

No. of
Weeks
on Diet

O rig ­
inal
Weight

Gain
in
Weight

F ood
Con­
sumed

Weight
at S tart
of R e­
ducing
P e rio d

2

I

162

98

1,735

260

232

20.0

16

1

172

47

1,612

219

196

20.0

8

2

190

57

1,401

247

222

37.5

33

2

155

62

1,518

217

192

37.5

7

3

162

52

1,420

214

181

45.0

188

■57

1,668

245

2 02

45.0

12

3

Weight
When
Killed

4

173

89

1,653

262

210

62.5

31

4

166

53

1,350

219

190

62.5

4

5

175

66

1,520

241

202

80.0

5

5

172

78

1,643

250

212

80.0

6

6

171

51

1,479

222

163

97.5

10

6

168

74

1,585

242

178

97.5

11

7

172

50

1,507

222

156

115.0

29

7

162

98

1,655

260

172

115.0

14

8

170

62

1,515

232

157

132.5

17

8

172

60

1,449

232

148

132.5

19

8

182

40

1,325

222

162

132.5

24

8

208

1,,732 •

256

134

132.5

27

8

182 ' '

1,377

226

155

132.5

.» /
00

3

44 .

122
T a b l e 21 ( C o n t i n u e d )

Blood Constituents
Body Constituents
C holes­
te ro l
(mg/100
ml)
45.8

Ash (%)

13.90

25.57

3.16

232.5

2.08

63.08

19.38

11.03

4.50

195.0

2.28

59.15

18.16

12.68

4.45

172.0

1.74

51.9

62.20 '

19.30

11.79

4.01

--

1.63

41.5

62.28

19.66

10.74

4.55

205.0

1.46

51.0

62.66

19.35

10.45

4.39

160.0

1.68

40.1

60.11

20.28

13.45

4.13

182.5

1.87

55.9

61.22

20.91

10.48

4.10

152.5

1.23

57.9

61.03

20.55

11.03

3.69

200.0

1.02

62.7

57.40

21.71

13.98

4.45

180.0

1.25

48.3

66.34

22.88

1.62

6.04

200.0

1.54

46.6

65.64

20.57

5.36

5.07

197.5

80.9

66.01

22.93

3.78

5.25

172.5

1.66

68.5

66.85

21.96 -

3.51 •

5.50

172.5

1.45

48.8

68.32

• 21.51s f'J

3 32

67.58

21.39 •

3.34

67.46

20.39

5.36

71.10

21.19

0.77

69.10

21.90

1.64

(%)

(%)

54.59

i

1—

P ro te in

»

F a t (%)

o

Pyruvic
Acid
( m g /100
ml)

P o ta s ­
sium
(ppm)

Moisture

123
T a b l e 22.

D ata fo r r a t s fed the h ig h - c a r b o h y d r a te d iet during p e r ­
i o d of w e i g h t l o s s .

Gain
in
Weight

F ood
Con­
sumed

Weight
at S tart
of R e­
ducing
P e rio d

Weight
When
Killed

F ood
Con­
sumed
During
Reducing
P erio d

No. of
Weeks
on Diet

O r ig ­
inal
Weight

38

1

171

89

1,615

260

230

24

103

1

162

56

1,247

218

194

24

104

2

171

73

1,393

244

215

45

114

2

167

47

1,218

214

194

45

42

3

170

44

1,390

214

180

66

106

3

164

79

1,393

243

198

66

45

4

159

104

1,499

263

212

87

41

4

159

59

1,660

218

166

87

116

5

189

53

1,484

242

180

108

118

5

174

71

1,397

245

183

108

100

6

180 .

44

1,260

224

164

129

30

6

190

42

1,639

242

171

129

120

7

160

60

1,257

220

164

150

37

7

168

90

1,623

258

176

150

112

8

170 '

62

1,286

232

132

171

44

8

156

74

1,444

230

122

171

123

8

168

56

1,388

224

150

171

99

8

173

83

1,508

256

165

171

119

8

163

63

1,262

226

160

171

Rat
No.

124
T a b l e 22 ( C o n t i n u e d )

Blood Constituents
Body Constituents
Pyruvic
Acid
(mg/100
ml)

Choles­
te ro l
(mg/100
ml)

F a t (%)

Ash (%)

P otas sium
(ppm)

17.56

20.40

4.00

187.5

2.76

57.6

61.06

19.86

11.69

4.43

157.5

1.54

43,8

53.48

18.45

19.63

4.51

172.5

1.64

49.5

57.10

16.48

14.51

3.74

187.5

1.39

19.1

64.13

20.19

8.20

4.94

195.0

1.90

35.8

66.81

19.73

5.'6 5

5.12

170.0

2.00

40.4

55.5

20.84

15.00

4.15

170.0

1.90

35.8

67.11

21.46

4.03

4.25

195.0

1.20

55.0

66.82

22.15

3.12

5.36

180.0

1.48

59.4

62.60

20.75

9.08

4.81

160.0

1.30

58.8

63.43

19.86

9.84

\.l 8

240.0

1.49

78.5

80.48

12.55

2.39

2.96

160.0

1.72

61.2

59.39

24.73

8.84

4.10

--

64.88

21.45

7.63

4.26

192.0

71.46

21.75

0.58

68.52

24.05

0.72

69.08

22.08

2.53

66.28

21.69

4.31

62.81

19.35

11.96

M oisture

P ro te in

(%)

(%)

55.70

64.2
1.58

60.0

4k

125
T a b l e 23.

Rat
Number

R a t s t h a t d ie d o r w e r e k i l l e d a n d t h e a p p a r e n t c a u s e .
Time on
E x p e r i­
m ent

Original
Weight

F inal Weight

Cause of Death

Corn Diet
1

1

150

130

Unknown

1

16

168

210

Pneumonia

15

18

172

212

Bloody urine, abnorm al
kidneys

23

16

155

192

Pneumonia

39

3

• 141

154

Pneumonia

46

20

153

210

Bloody urine, abnorm al
kidneys

48

21

176

246

Pneumonia

101

21

191

200

Bloody urine, abnormal
kidneys

111

4

162

131

Pneumonia

142

8

170

180

Pneumonia

Wheat Diet
51

. 14

141

183

Pneumonia

56

20

154

216

Pneumonia

62

17

192

2.20

Pneumonia

70

21

155

160

Killed, abnormal growth
of teeth. Loss of
weight.

,r.

126
T a b l e 23 ( C o n t i n u e d )

Rat
Number

Time on
E x p e ri­
ment

F in al Weight

Weight

Cause of Death

72

21

160

170

Killed, abnormal
growth of teeth; loss
of weight.

77

'21

178

224

Killed. No upper
teeth; lower teeth are
white and b rittle , loss
of weight.

* •1

Rat
Number

Diet

Cause

Reducing Diet
)
13

High carbohydrate

Pneumonia

18

High fat

E a r infection

20

High fat ad libitum

E ar infection