A large, genetically based UK study sheds some new light on a long-running concern in adolescent mental health. It appears that when teenagers are unhappy with their bodies, the ramifications of that can spill well into adulthood.
This new research, which appears in The Lancet Psychiatry, suggests that negative body image at age 16 serves as a bellwether for more severe eating disorder symptoms, greater depressive symptoms, and higher BMI in the years that follow. And these relationships, researchers argue, can’t be written off as a product of a shared family environment or even genetics.
The findings come from the Twins Early Development Study (TEDS), a long-running cohort of more than 13,000 twin pairs born in England and Wales in the mid-1990s. Researchers combed through the data from more than 2,100 adolescents that included extensive data on body dissatisfaction. The team then tracked participants into their early and mid-20s, measuring eating disorder symptoms at age 21 and depressive symptoms and BMI at ages 21 and 26.
One Things Leads to Another
The international group of researchers found that for every point increase on a seven-point scale of body dissatisfaction at age 16, participants showed nearly two additional points of eating disorder symptoms and a notable jump in depressive symptoms by the time they turned 21. Their BMI also crept up over time.
These associations lingered even after the team accounted for several external factors, such as childhood BMI, pubertal timing, socioeconomic status, parental BMI, maternal depression, peer victimization, among others.
Girls appeared to show a stronger link between early body dissatisfaction and later eating disorder symptoms than boys. The discovery lines up with broader research on adolescent body image. As for depressive symptoms and BMI, the relationships remained consistent across genders.
A Causal Connection?
The study’s big draw is its twin-difference approach. By comparing identical and fraternal twins from the same households, researchers could control for many confounders that normally cloud the waters of body-image research.
Among fraternal twins, the twin with higher body dissatisfaction at 16 consistently endured worse eating disorder and depressive symptoms later on, as well as a higher BMI.
Among identical twins, the effect sizes fell somewhat for eating disorder symptoms and BMI but remained significant for depressive symptoms. That pattern suggests that genetics explain part (but not all) of the relationship between early body dissatisfaction and later outcomes.
In other words, the findings point toward a causal pathway. Feeling unhappy with one’s body in adolescence can set the stage for poorer mental health in adulthood.
The Role of Genetic Overlap
A deeper dive into the data using ACE models revealed that body dissatisfaction itself is inherited –at least in part. Eating disorder symptoms, depressive symptoms, and BMI also showed substantial genetic influences.
But the strongest shared genetic signal appeared between body dissatisfaction and eating disorder symptoms. About three-quarters of their correlation stemmed from overlapping genetic factors. The genetic overlap with depressive symptoms and BMI was smaller but still meaningful.
Environmental influences unique to each twin also contributed modestly to the associations.
A Growing Public Health Challenge
This new research arrives when body dissatisfaction is ticking upward for young people. And its link to depression appears to be stronger than ever. Researchers note that weight- and appearance-related pressures (wherever they come from) have ramped up.
Although the authors of this study can’t rule out residual confounding completely, the results still offer some of the strongest evidence so far that addressing body dissatisfaction could help stave off mental-health problems later on. The authors add that effective prevention would probably demand coordinated efforts across families, schools, social-media environments, and public-health campaigns.
Body dissatisfaction, the researchers add, is widespread, but treatable. Interventions based on cognitive-behavioral and cognitive-dissonance approaches have certainly shown some potential. But more expansive, structural solutions – such as regulating harmful social-media content or redesigning obesity-prevention campaigns – might be critical to making a long-term difference.
Further Reading
Childhood Eating Habits May Shape Adolescent Mental Health
New Insights Into Eating Disorders
Eating Disorders May Be More Prevalent, Harder To Diagnose In Athletes
