Mid-adolescent stress differentially affects binge-like intake of sucrose across estrous cycles in female rats✰.

Abstract Binge eating disorder (BED), characterized by excessive food consumption within a discrete period of time, is the most prevalent of all eating disorders, with higher rates in women than men. Chronic stress, particularly during adolescence, is a significant risk factor for BED in women, but the mechanism underlying this relationship remains elusive. We investigated the phenomenon by testing the impact of mid-adolescent intermittent physical stress (IPS) on binge-like intake of sucrose in adult female rats, assessing how the behavior changed across reproductive cycles. One hundred and nineteen Long-Evans rats were exposed to IPS (n=59) or no stress (NS; n=60) for 12 days during mid-adolescence (PD35-46). Binge-like eating was induced in adult animals using an intermittent access protocol: animals were provided with 12h or 24h access to sucrose, 12h access to saccharin, or 12h access to food over 28 days. After 1- or 28-day abstinence, compulsive responding for sucrose was measured using a conditioned suppression paradigm. Rats given 12h access to sucrose developed binge-like intake, measured as increased consumption during the first hour; the effect was magnified in IPS animals and most pronounced during proestrous. Solution intake in IPS rats was predicted by open arm entries in the elevated plus maze, suggesting that increased risk-taking behaviour is associated with greater binge-like eating. IPS blocked conditioned suppression after 28 days of abstinence, pointing to a role of mid-adolescent stress in compulsivity. Collectively, these findings emphasize the impact of stress on the emergence of binge eating in females and suggest that intervention programs for women with a history of adolescent adversity should be investigated as a means to reduce risk for BED.