Variations in maternal care influence vulnerability to stress-induced binge eating in female rats

Binge eating disorder (BED) is characterized by intermittent, discrete periods of uncontrollable consumption during which huge quantities of high-fat food are eaten. The onset of BED occurs most frequently in adolescent or young adult females and is often associated with a history of dieting and psychological stress. Animal research suggests the importance of two synergistic factors in the aetiology of binge eating: a history of restriction-refeeding cycles (i.e., "yo-yo" dieting) and exposure to acute stress. In the rat, natural variations in maternal licking and grooming (LG) of pups during the first week of life are associated with long-lasting individual differences in offspring sensitivity to stress. The current set of experiments examined the effects of restriction--refeeding--footshock cycles on intake of highly palatable (HP) food in adolescent and adult female offspring of Low, Mid, and High LG dams. Following cycles of food restriction or unlimited food access, sated rats were exposed to footshock and their intake of HP food and chow was measured at 2, 4, and 22 h post-shock. Adolescent offspring of Low LG mothers displayed shock-induced binge eating, regardless of food-restriction history. In contrast, adolescent female offspring of Mid and High LG mothers failed to exhibit shock-induced increases in food intake. We saw no evidence of binge eating when shock was introduced in adulthood. The data suggest that low levels of maternal care in early life are associated with greater vulnerability to the later development of stress-related binge eating and further that this heightened vulnerability manifests during the adolescent period.