BACKGROUND: Children with rs9939609 FTO variant alleles (homozygous = AA and heterozygous = AT) are predisposed to greater adiposity than are those with 2 wild-type alleles (TT).<br /><br />OBJECTIVE: Because FTO is highly expressed in hypothalamic regions that are important for appetite, FTO genotype may affect energy balance by influencing eating behavior. Loss of control (LOC) eating, a behavior commonly reported by overweight youth, predicts excessive weight gain in children. However, the relation between FTO genotype and LOC eating has not been previously examined.<br /><br />DESIGN: Two-hundred eighty-nine youth aged 6-19 y were genotyped for rs9939609, underwent body-composition measurements, and were interviewed to determine the presence or absence of LOC eating. A subset (n = 190) participated in a lunch buffet test meal designed to model an LOC eating episode. Subjects with AA and AT genotypes were grouped together for comparison with wild-type TT subjects.<br /><br />RESULTS: Subjects with at least one A allele (67.7%) had significantly greater body mass indexes, body mass index z scores (P < 0.01), and fat mass (P < 0.05). Of the AA/AT subjects, 34.7% reported LOC compared with 18.2% of the TT subjects (P = 0.002). Although total energy intake at the test meal did not differ significantly by genotype (P = 0.61), AA/AT subjects consumed a greater percentage of energy from fat than did the TT subjects (P < 0.01).<br /><br />CONCLUSIONS: Children and adolescents with 1 or 2 FTO rs9939609 obesity-risk alleles report more frequent LOC eating episodes and select foods higher in fat at a buffet meal. Both LOC eating and more frequent selection of energy-dense, palatable foods may be mechanisms through which variant FTO alleles lead to excess body weight.
Tanofsky-Kraff, M., Han, J. C., Anandalingam, K., Shomaker, L. B., Columbo, K. M., Wolkoff, L. E., … Yanovski, J. A. (2009). The FTO gene rs9939609 obesity-risk allele and loss of control over eating. American Journal of Clinical Nutrition, 90(6), 1483–1488. https://doi.org/10.3945/ajcn.2009.28439