Genetic and environmental influences on restrained eating behavior

Objective: We examined the relative contributions of genetic and environmental influences to restrained eating. Method: Restrained eating was assessed by the Restraint Scale in a survey mailed to all twins enrolled in the University of Washington Twin Registry. We used structural equation modeling to estimate genetic and nongenetic contributions to restrained eating. Results: 1,196 monozygotic (MZ), 456 same‐sex dizygotic (DZ) twins, and 447 opposite‐sex twins were included in analyses. Restraint Scale scores were more closely correlated in MZ twins ( r male = .55, r female = .55) than in same‐sex DZ twins ( r male = .31, r female = .19). Based on structural equation modeling, the estimated heritability for restrained eating, adjusted for body mass index (BMI) and sex, was 43% (95% confidence interval 35–50%). There was little evidence for common environmental effects. Discussion: These results indicate an inherited component to restrained eating. Genes could influence restrained eating directly or through inherited mediators such as personality factors or tendencies to gain weight. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2009