Background: Stress has been hypothesised to be involved in obesity development, also in children. More research is needed into the role of lifestyle factors in this association.
Purpose: This study investigates the cross-sectional relationship between stress and body composition and, more importantly, the possible moderating or mediating role of lifestyle factors.
Methods: A total of 355 Belgian children (5-10 years old) participating in the baseline 'Children's Body composition and Stress' survey were included in this study. The following variables were studied: psychosocial stress (i.e. stressful events, emotions and behavioural/emotional problems, salivary cortisol), stress-related lifestyle factors (high-caloric snack consumption frequency, screen exposure time and sleep duration) and body composition parameters [BMI z-score, waist to height ratio (WHtR)]. Using linear regression analyses (adjusted for sex, age and socio-economic status), the relation between stress and body composition and, more importantly, the possible moderating or mediating role of lifestyle factors was tested.
Results: No association was observed between body composition and negative emotions, conduct and emotional problems and salivary cortisol. However, negative life events were positively and happiness was negatively associated with BMI z-score and WHtR. Peer problems and WHtR were positively associated in girls only. These associations were not significantly reduced after correction for lifestyle factors. Nevertheless, all lifestyle parameters moderated one or more stress-body composition associations, resulting in even more significant relations after subgroup analysis.
Conclusion: Childhood stress was positively related to both overall and central adiposity measures with lifestyle factors acting as moderators but not as mediators. Thus, lifestyle could be a vulnerability factor in stress-induced adiposity, creating a perspective for multi-factorial obesity prevention, targeting stress and lifestyle factors in parallel.