Genetic and environmental contributions to obesity and binge eating

Objective: Binge eating is present in a substantial proportion of obese individuals. A tendency toward obesity has been identified as a risk factor for eating disorders such as bulimia nervosa and binge eating disorder. The purpose of this article was to determine the extent of overlap between genetic and environmental factors that contribute to the liability to obesity and binge eating. Research Method: In a population-based sample of 2163 female twins, we conducted bivariate twin modeling to explore the relation between the genetic and environmental risk factors for obesity and binge eating. Results: Bivariate twin modeling revealed substantial heritability for obesity (0.86: 95% Cl, 0.77-0.94), moderate heritability for binge eating (0.49: 95% Cl, 0.38-0.61), and a modest genetic correlation of +.34 (95% Cl, 0.19-0.50) between the two traits. Conclusions: Both binge eating and obesity are heritable conditions, and there seems to be only modest overlap in the genetic risk factors that increase liability to each condition. (C) 2003 by Wiley Periodicals, Inc.