Genetic and environmental influences on eating behavior: the Swedish young male twins study

Background: Eating behavior may be implicated in the increasing prevalence of overweight and obesity, presumably in relation to easy access to energy-dense and highly palatable foods. Objective: The aim of the present study was to disentangle genetic and environmental influences on eating behavior in a population-based cohort of male twins. Design: The study included 326 dizygotic and 456 monozygotic male twin pairs aged 23-29 y from Sweden. The revised 21-item version of the Three-Factor Eating Questionnaire (TFEQ-R21) was used to assess eating behavior. This validated instrument consists of 3 dimensions: cognitive restraint, emotional eating, and uncontrolled eating. Structural equation modeling was used to estimate the heritability of eating behavior. Results: Cognitive restraint was the only TFEQ-R21 scale that significantly correlated with BMI (r = 0.39, P < 0.0001). The best-fitted models gave a heritability of 59% (95% CI: 52%,66%) for cognitive restraint, 60% (95% CI: 52%, 67%) for emotional eating, and 45% (95% CI: 36%, 53%) for uncontrolled eating. Conclusions: These results show the great importance of genetic factors in the eating behavior of a large, unselected population of young adult male twins. Nonshared environmental factors were also important, whereas shared environmental factors did not contribute to eating behavior.