Differential heritability of eating attitudes and behaviors in prepubertal versus pubertal twins

Objective: Differential heritability of eating pathology in prepubertal, pubertal, and 17-year-old twins was examined using a population-based twin sample. Method: Participants included 530 11-year-old (452 prepubertal, 78 pubertal twins) and 602 17-year-old female twins from the Minnesota Twin Family Study. Puberty was assessed with the Pubertal Development Scale, and general eating pathology was assessed with the total score from the Minnesota Eating Disorders Inventory (M-EDI). Results: M-EDI total score intraclass correlations for the pubertal 11-year-old group were more similar to the 17-year-old twins' than the prepubertal 11-year-old twins, suggesting similar levels of genetic influence in the pubertal and older adolescent cohort. Model-fitting corroborated these impressions, indicating that genetic factors accounted for 0% of the variance in 11-year-old prepubertal twins but 54% of the variance in 11-year-old pubertal and 17-year-old twins. Discussion: Findings suggest that a portion of the genetic influence on eating pathology may become activated during puberty. (C) 2003 by Wiley Periodicals, Inc.