Binge Eating in Rats Produced by Combining Dieting with Stress

Abstract

This unit describes a rodent model of binge eating based on cyclic restriction, refeeding, footshock, and intermittent access to palatable food. These conditions mimic dieting, stress, and "junk" food indulgence, respectively, all common etiological and maintenance factors in human binge eating. Four groups of rats are used: one subjected to cyclic food restriction, another to acute footshock stress, another to both of these (R + S), and a control. Neither cyclic restriction nor stress alone produces binge eating, but the R + S rats, despite satiety, double their intake of palatable food in a discrete period of time (i.e., binge) when stressed. This protocol recapitulates critical properties of human binge eating, namely preference for palatable food, dieting- and stress-induced vulnerability to binging, and eating for reward versus metabolic need. This protocol permits study of the psychobiological underpinnings of binge eating and possibly also of addiction, impulsivity, and depression, which are co-morbid with binge eating.