Approximately one-third of adults in the United States are obese. Following a moderate increase in obesity during the 1970s, obesity prevalence in the U.S. has more than doubled since the 1980s. There are also large black and white disparities in obesity prevalence. Obesity is an important public health problem because it is related to many comorbidities, including heart disease and cancer that cause premature mortality. Since 2000, the Centers for Disease Control and Prevention (CDC) Division of Nutrition, Physical Activity, and Obesity (DNPAO) has funded 37 state health departments to reduce the rising obesity in populations within their states. Importantly to-date there have not been any national studies evaluating the impacts of these CDC-DNPAO funded programs on changing obesity prevalence within and across funded and non-funded states. This dissertation research therefore, investigated the impacts of CDC-DNPAO state-specific obesity intervention programs on the geography of adult obesity in the United States at the county level. The Behavioral Risk Factor Surveillance System (BRFSS) and census data comprised the data used for this research. Theoretical frameworks and techniques were applied from the fields of health geography, population geography and economics. This dissertation research included three independent and interrelated studies described below. The first study utilized a spatial microsimulation approach to indirectly estimate obesity prevalence at the county level. Obtaining a comprehensive obesity dataset across all counties is challenging because the BRFSS is designed to estimate obesity prevalence only at the national or state levels. There is a need therefore to apply spatial microsimulation modeling to virtually replicate the demographic characteristics of BRFSS survey respondents and allocate their BMI status at the county level. Obesity prevalence estimates—i.e., the number of obese cases/ population at risk from the spatial microsimulation modeling were mapped to visualize and explore the spatial patterns and detect obesity clusters. Counties in Southern states, especially along the Mississippi River and the Appalachian Mountains, and counties containing or in proximity to American Indian reservation sites had elevated obesity prevalence rates across time, 2000 to 2010. The output from the spatial microsimulation is also used in the subsequent two studies in this dissertation research. The second study evaluated the impact of the CDC-DNPAO programs on obesity prevalence in states with and without funding using an interrupt time series modeling technique to identify where state CDC-DNPAO programs were more or less protective of adult obesity and where to target future interventions. The third study partitioned the variance in obesity prevalence between blacks and whites into explainable and unexplainable portions of obesity using a reweighting decomposition technique to further understand these disparities.The findings from this research identified where programs have been successful in controlling obesity and where to target future interventions to reduce obesity, reduce racial disparities in obesity and improve population health. The translation of this knowledge will also be helpful to reduce obesity in other countries, particularly those countries experiencing a transition toward obesity in their populations.
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