Body dissatisfaction may drive development of eating disorder, depressive symptoms

Body dissatisfaction in adolescence may directly contribute to an increase in symptoms of eating disorder and depression, according to a study.

Researchers used data from the Twins Early Development Study, which involved twins born in England and Wales between 1994 and 1996. They identified participants with complete data on body dissatisfaction at age 16 years, which was evaluated using the Eating Disorder Diagnostic Scale capturing weight and shape concerns.

Outcomes included eating disorder symptoms at age 21 years (12-item modified version of the Eating Disorder Inventory—2), depressive symptoms (8-item Short Mood and Feelings Questionnaire), and BMI at ages 21 years and 26 years.

The analysis included 2,183 twins (60.2 percent female, 93.5 percent White, 61.7 percent dizygotic). Each one-point increase in body dissatisfaction was associated with a 1.99-point (95 percent confidence interval [CI], 1.73–2.26) higher eating disorder symptom score, a 0.59-point (95 percent CI, 0.46–0.73) higher depressive symptom score, and a 0.27-kg/m² (95 percent CI, 0.16–0.38) higher BMI.

In monozygotic and dizygotic twin difference analyses, higher body dissatisfaction was also linked to more severe eating disorder and depressive symptoms. The association with BMI, on the other hand, was smaller and less precisely estimated in monozygotic twins.

Twin modelling showed that the association between body dissatisfaction and the outcomes was predominantly genetic. Shared genetic factors explained most of the covariance between body dissatisfaction and eating disorder symptoms in particular, with a smaller contribution from nonshared environmental influences.

These findings suggest a causal relationship between body dissatisfaction and eating disorder and depressive symptoms. Therefore, reducing the emergence of body dissatisfaction among adolescents could help improve mental health outcomes.