Objective: The current study explores the extent to which genetic and environmental factors influence liability to binge eating in the absence of compensatory behaviors (BE) in a population-based sample of twins.
Method: Questionnaire data on 8,045 same-sex and opposite-sex twins, aged 18-31 years, from a Norwegian twin registry were used to assess BE during the last 6 months.
Results: The best-fitting biometrical model suggested that the heritability of BE was 41% (95% confidence interval [CI]: 0.31-0.50). Individual environmental factors accounted for the rest of the variance (59%; 95% CI: 0.50-0.69). No significant sex differences were found, but the statistical power to detect such effects was low. Shared environmental influences on the liability to BE in males could not be ruled out.
Discussion: The findings indicate significant additive genetic influences on BE, supporting the validity of the core features of binge eating disorder as a diagnostic category.