[Dose-response relationship of multidimensional lifestyle with anxiety and depression in children and adolescents: a moderated analysis on overweight/obesity effect].

Objective: To analyze the dose-response relationship of multidimensional lifestyle (diet, physical activity, screen watching, sleep) and anxiety/depression symptoms in children and adolescents, and evaluate whether overweight/obesity moderates this relationship. Methods: A cross-sectional survey was conducted in 1 133 students aged 7-17 years. Anxiety and depression symptoms were assessed with the Social Anxiety Scale for Children and the Children's Depression Inventory, respectively. Lifestyle variables were collected through questionnaire survey. Restricted cubic spline models were fitted to estimate dose-response curves, and the analyses were stratified by overweight/obesity status. Results: In the 1 133 children and adolescents surveyed, 329 were positive for anxiety symptoms (29.04%) and 130 were positive for depression symptoms(11.47%).A total of 409 children and adolescents were overweight/obese (36.10%). Higher composite healthy-lifestyle score was associated with lower odds of anxiety symptoms (OR=0.68, 95%CI:0.55-0.84, P<0.001) and depression symptoms (OR=0.69, 95%CI:0.50-0.94, P=0.019). At the individual level, daily vegetable intake (non-linear P=0.016), daily moderate-intensity exercise duration (non-linear P=0.004), and daily sleep duration (non-linear P=0.031) showed non-linear associations with anxiety symptom scores. Daily fruit intake (non-linear P<0.001), daily vegetable intake (non-linear P=0.003), daily moderate-intensity exercise duration (non-linear P=0.011), daily walking time (non-linear P<0.001), daily non-study screen time (non-linear P=0.033), and daily sleep duration (non-linear P<0.001) showed non-linear associations with depression symptom scores. Moderation analysis revealed that only the dose-response relationship between daily vegetable intake and depression symptoms was significantly moderated by obesity status (interaction P=0.039). Stratified analysis indicated that the non-linear protective effects of lifestyle factors were more pronounced in the non-overweight/obese group. In the overweight/obese participants, non-linear associations for most lifestyle factors were attenuated. Conclusions: Multidimensional lifestyle factors have dose-response relationship with anxiety and depression symptoms in children and adolescents, and overweight/obesity might attenuate the health effects of multidimensional lifestyles. Lifestyle interventions are recommended for non-overweight/obese children and adolescents, whereas integrated weight-management and targeted behavioral intervention strategies are needed for those with overweight/obesity.