A Genetic Link Is Identified for Binge Eating in Adolescence

A positive association is found between a polymorphism in the FTO gene and binge eating.

Evidence from behavioral genetic studies is increasingly pointing to a genetic link to increased risk of binge eating. However, BED is a more recent addition to the group of recognized eating disorders, and thus few studies before this had traced a possible genetic link specifically for BED.

Dr. Nadia Micali and colleagues at University College and King’s College, London, Harvard Medical School, and the University of Queensland, Australia, hypothesized that higher body mass index (BMI, kg/m²) and binge eating might share a genetic etiology (Obesity. 2015. 23:1729). Dr. Micali and colleagues utilized data from the Avon Longitudinal Study of Parents and Children. During this population-based prospective study of women and their children living in Avon, UK, the teens were assessed at age 14 (n=5958) and again at age 16 (n=4948). During the longitudinal study, binge eating was assessed with a two-part question in which participants were asked about how often in the past year they had eaten a very large amount of food. Those who answered yes were then asked whether they felt “out of control” during the episodes; affirmative answers to both questions yielded a BED diagnosis. The researchers analyzed 32 BMI-associated single nucleotide polymorphisms, or SNPs previously linked to BMI.

The FTO gene and binge eating

The authors reported that the overall mean prevalence of binge eating during adolescence was 5.6% at age 14 and 11.2% at age 16, and binge eating was more common among girls than among boys at both ages (7.4% vs. 3.5% at age 14 and 16.1% vs. 4.4% at age 16).

The results of Dr. Micali and colleagues’ study suggest a link between a polymorphism in the FTO gene and binge eating in adolescents. This factor may influence food intake, food choices, and control over eating. Girls within or near the FTO locus are seemingly associated with a preference for energy-dense foods, greater intake of food, less sensitivity to cues of satiety, and loss of control eating episodes.

The authors note that this is the first study to investigate an association between binge eating in adolescence and 32 SNPs that have been associated with BMI, and suggest that as future studies further delineate genetic correlates of obesity, it will be possible to more thoroughly test the mechanisms underlying the relationship between obesity, binge eating, and the FTO gene.