Increased Heritability of Disordered Eating Across Puberty: A Replication in a Developmentally Diverse Sample

Objective: Previous twin research has shown that genetic influences on disordered eating symptoms increase across puberty (Culbert, Burt, McGue, Iacono, & Klump, J Abnorm Psychol, 2009; Klump, McGue, & Iacono, Int J Eat... [ view full abstract ]

Objective: Previous twin research has shown that genetic influences on disordered eating symptoms increase across puberty (Culbert, Burt, McGue, Iacono, & Klump, J Abnorm Psychol, 2009; Klump, McGue, & Iacono, Int J Eat Disord, 2003; Klump, Perkins, Burt, McGue, & Iacono, Psychol Med, 2007). However, almost all studies were conducted in the same sample of twins, and this sample had limited variability in pubertal development (e.g., studying twins who were age 11 or age 14 only). The current study aimed to replicate past findings in a new twin sample that included the full range of variability in age (ages 8-25 years old) and pubertal development (pre-puberty through post-puberty). Methods: Participants included 1,568 same-sex female twins from the Michigan State University Twin Registry. Disordered eating symptoms were assessed with the total score (assessing body dissatisfaction, weight preoccupation, binge eating, and compensatory behaviors) from the Minnesota Eating Behavior Survey, while pubertal development was assessed with the Pubertal Development Scale. Results: Twin moderation models showed significant linear increases in genetic effects from pre-puberty (3%) to post-puberty (45%), even after controlling for the effects of age and body mass index (BMI). Discussion: Results replicated previous findings that genetic effects on disordered eating increase across pubertal development. Because analyses controlled for other relevant factors (i.e., age and BMI), these results indirectly suggest that ovarian hormones, a key element in pubertal development, may be responsible for this increase in heritability. Further research should directly determine the role of ovarian hormones in this heritability increase.