Childhood body composition and fitness influence anxiety and depression—higher visceral fat increases risk, while greater lean mass and cardiorespiratory fitness offer protection. Digest
Preadolescence is a critical stage for both physical growth and emotional well-being, and new findings highlight how body fat, lean mass, and fitness may connect with anxiety and depression.
The study included 207 children aged 8 to 11 from the Greater Boston area, each completing a single lab visit. During this visit, their body composition was measured with dual-energy X-ray absorptiometry (DXA), which provided detailed readings of overall body fat, lean mass, and visceral fat (fat stored around internal organs). To assess fitness, each child performed a treadmill test with respiratory monitoring to determine VO2peak, the maximum rate of oxygen consumption during peak exertion. Participants also filled out questionnaires assessing trait anxiety and depressive symptoms.
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The results suggest meaningful patterns linking physical traits and mental health:
- Higher body fat percentage was associated with greater anxiety but not with depression.
- Higher visceral fat was linked to higher levels of both anxiety and depression.
- Greater lean mass was connected to fewer symptoms of both anxiety and depression.
- Higher cardiorespiratory fitness was linked to lower anxiety as well as lower depression.
- Body mass index showed no significant associations, likely reflecting its limitations compared with more precise measurements.
What might explain these links? Visceral fat promotes chronic low-grade inflammation and releases immune signals that can alter brain circuits involved in mood regulation. By contrast, fitness and muscle mass may promote resilience by supporting healthier stress responses. They also release myokines, which are hormone-like proteins that lower inflammation and protect brain health. Together, these processes suggest a biological pathway through which body fat, lean mass, and fitness may shape emotional well-being in children.
Conclusion:
Children with more visceral fat and lower fitness tended to report greater anxiety and depression, while those with more muscle mass reported fewer symptoms. However, because this study provides only an observational snapshot in time, it cannot determine how much differences in body composition and fitness influence mood regulation and how much they are influenced by it. Long-term and intervention studies are needed to clarify this relationship and identify the best strategies for early prevention. Nevertheless, these findings underscore that fostering regular physical activity and balanced nutrition from early childhood may not only promote physical health but also mental well-being. Learn more about lifestyle factors that can improve depression in this clip featuring Dr. Charles Raison.