Binge eating is a significantly heritable phenotype, but efforts to identify specific risk genes have fallen short. Identification of animal strain differences in risk for binge eating could highlight genetic differences across animals that can be exploited in future animal and molecular genetic research. The current study aimed to explore strain differences in risk for binge eating in Sprague-Dawley versus Wistar female rats using the Binge Eating Resistant/Binge Eating Prone model. A sample of male Sprague Dawley rats, a known low-risk group for binge eating, was included as a comparison group. A total of 83 rats (23 Wistar female, 30 Sprague-Dawley female, 30 Sprague-Dawley male) completed a protocol of intermittently administered, palatable food. Binge eating prone (BEP) and binge eating resistant (BER) rats were identified using a tertile approach. Sprague-Dawley female rats consumed the highest amount of palatable food and were more likely to be classified as BEP compared to Wistar female and Sprague-Dawley male rats. Wistar female rats were not significantly different from Sprague-Dawley male rats in their palatable food intake and tendency to be classified as BER rather than BEP. Sprague-Dawley female rats appear to be a particularly vulnerable strain for binge eating. Comparisons between this strain and others could help identify specific genetic/biological factors that differentiate this strain from lower risk strains. The opioid and dopaminergic systems, linked to binge eating in humans, are possible candidates to explore. Strain differences in these reward processes and their genetic/biological underpinnings could help increase understanding of individual differences in risk for binge eating in humans.
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