Tween Mental Health Linked with Body Composition

Higher lean mass and cardiorespiratory fitness is associated with fewer anxiety and depression symptoms in tweens, research suggests, while excess adiposity is conversely associated with their poorer mental health.

The findings, in JAMA Network Open, highlight the importance of assessing these factors to target interventions that can improve preadolescent development and well-being.

“Our findings suggest that fitness and lean mass may serve as protective factors, while adiposity may confer risk,” reported the team led by Lauren Raine, PhD, from Northeastern University in Boston, Massachusetts.

“These distinctions, detectable even in preadolescence, could support early identification of children at greater risk for mental health symptoms.

“Integrating modifiable factors like fitness and body composition into routine pediatric assessments may help guide preventative care and early intervention to improve children’s mental health outcomes.”

Nearly one in five children and adolescents experience mental health challenges, the authors pointed out. The most common of these in children are anxiety and depression, with rates rising by nearly 30% between 2016 and 2020.

Observing that two international studies have identified increased body mass index (BMI) and obesity as critical risk factors for anxiety and depression in youth, the team decided to investigation the association further.

The study assessed how adiposity, lean tissue, and fitness were associated with symptoms of anxiety and depression in 207 volunteer children, aged eight to 11 years, without a prior mental health diagnosis.

The researchers believe theirs is the first study of its kind to use dual-energy X-ray absorptiometry (DXA) body composition measures and a VO₂peak test, the criterion standard for cardiorespiratory fitness assessment.

Body fat percentage, visceral adipose tissue (VAT), and lean mass together with and fitness were significantly but distinctly associated with anxiety and depression.

Lean mass and VO₂peak were negatively associated with both outcomes, so that children with greater lean mass and higher fitness levels reported fewer symptoms of anxiety and depression.

By contrast, higher body fat percentage and VAT were associated with greater anxiety symptoms, with VAT also linked with increased depressive symptoms.

Of note, body fat percentage was not associated with depression, and BMI was unrelated to either outcome, although both trended in the expected direction and aligned with prior research.

“By using sensitive measures of body composition rather than conventional anthropometric methods, these findings underscore the importance of distinguishing between tissue types when examining mental health concerns in children,” Raine and co-workers reported.

They added: “The present study suggests that the association between body composition and mental health is complex and highlights the potential significance of adipose tissue location, such as VAT.”

“One possible mechanism is the abnormal secretion of proinflammatory adipokines and lipokines, which increase with VAT, and have been implicated in heightened neuroinflammatory and dysregulation of mood-related brain regions, including the hippocampus and amygdala. These processes may underpin the bidirectional link between obesity and depression.”

They further noted: “In contrast, lean mass and cardiorespiratory fitness may act as protective factors. Fitness, enhanced through regular physical activity, has been linked to reduced stress reactivity and more adaptive neuroendocrine and physiological responses to physical and psychosocial stressors.

“Physical activity may promote an anti-inflammatory state, improve immune function, and enhance neuroplasticity and growth factor expression.”