Network analysis of lifestyle behaviors and anxiety in children and adolescents: gender and school-stage heterogeneity

Background Anxiety disorders are a growing public health concern among children and adolescents, and lifestyle behaviors are recognized as modifiable factors. However, how lifestyle behaviors and anxiety symptoms interrelate, and whether these associations differ by gender and developmental stage remains unclear. Objective This study examined the network structure of lifestyle behaviors (physical activity, sleep, diet) and anxiety symptoms in children and adolescents, examining gender- and school-stage-specific differences. Methods A total of 1,971 children and adolescents from China (50.8% male, 49.2% female; 69.8% primary school, 30.2% middle school) participated in this cross-sectional study. Lifestyle behaviors were assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and self-developed composite indices for sleep (4-item) and diet (3-item) behaviors, while anxiety symptoms were measured using the Generalized Anxiety Disorder-7 scale (GAD-7). Network models were estimated using regularized partial correlations. Expected influence (EI) and bridge EI were used to identify central and bridge nodes. Results Moderate-intensity physical activity (MPA) emerged as the most central node (EI = 1.10), followed by anxiety symptoms GAD06 (EI = 0.96) and GAD03 (EI = 0.89). Sleep was identified as the strongest bridge node (bridge EI = −0.230), showing the strongest cross-domain partial correlation between lifestyle behaviors and anxiety symptoms. Gender-specific analyses showed significantly stronger sleep bridge effects in females (bridge EI = −0.270) than in males (bridge EI = −0.190, p = 0.033), despite comparable overall network structures ( p = 0.263). Developmental comparisons indicated that primary school students exhibited stronger behavior-symptom associations, whereas middle school students showed more consolidated symptom-symptom connectivity. All networks demonstrated good stability (CS-coefficients: 0.67–0.75). Conclusion Sleep was the most prominent bridge node linking lifestyle behaviors and anxiety symptoms, with gender-specific and developmental differences observed. These findings are descriptive and hypothesis-generating; claims regarding mechanisms or intervention targets require longitudinal and experimental evidence.