Are obesity risk genes associated with binge eating in adolescence?

Nadia Micali, Alison E Field, Janet L Treasure, David M Evans

Cognitions and behaviors characteristic of binge eating are associated with a polymorphism in the FTO gene, robustly related to body mass index (BMI) and obesity risk. We investigated the association between binge eating and the individual and combined effect of 32 SNPs robustly associated with BMI in a population-based sample. We hypothesized that higher BMI and binge eating might share a common genetic etiology. Binge eating was assessed in adolescents from the Avon Longitudinal Study of Parents and Children at age 14 (n = 5,958) and 16 years (n = 4,948). We tested associations between 32 BMI-related SNPs and binge eating in crude and BMI-, age-, and gender-adjusted regression models. Crude analyses showed an association between binge eating and rs1558902 (FTO) that persisted after adjustment for BMI (OR = 1.20, P = 8 × 10(-3) ). A weighted allelic score consisting of all 32 BMI-related SNPs was associated with binge eating (P = 8 × 10(-4) ); this association attenuated (P = 0.08) when rs1558902 was removed from the weighted allelic score. BMI-related genes are associated with adolescent binge eating, in particular an FTO polymorphism. Although replication is needed, our findings have biological plausibility and are consistent with a postulated effect of FTO on appetite and food intake. Future studies should aim to understand the mechanisms underlying the relationship between FTO, binge eating, and obesity.