WEDNESDAY, Dec. 17, 2025 (HealthDay News) -- Body dissatisfaction may causally increase eating disorder and depressive symptoms, according to a study published in the January issue of The Lancet Psychiatry.Ilaria Costantini, Ph.D., from University College London, and colleagues used data from the Twins Early Development Study to examine the longitudinal associations between body dissatisfaction at age 16 years and later eating disorder and depressive symptoms, as well as body mass index (BMI), in young adulthood. A total of 2,183 twins (61.7 percent dizygotic) were included in the study.The researchers observed an association for a 1-point increase in body dissatisfaction with a 1.99-point higher eating disorder symptom score, a 0.59-point higher depressive symptom score, and a 0.27 kg/m2 higher BMI, on average. Higher body dissatisfaction was also associated with more severe eating disorder and depressive symptoms in monozygotic and dizygotic twin difference analyses. The association was smaller for BMI and was less precisely estimated in monozygotic twins. Most of the covariance between body dissatisfaction and these traits, especially eating disorder symptoms, was explained by shared genetic factors as indicated by twin modeling, with a smaller contribution from nonshared environmental influences."It is vital that body dissatisfaction is tackled head-on during the teenage years across multiple settings, including in the school system, government health care strategies, and in the wider culture," senior author Francesca Solmi, Ph.D., also from University College London, said in a statement.One author disclosed ties to the health care industry; two authors disclosed ties to the publishing industry.Abstract/Full Text.Sign up for our weekly HealthDay newsletter