To explore the impact mechanism of peer relationship networks in children and adolescents on overweight and obesity, and to provide some empirical basis for the health management and intervention of overweight and obesity in children and adolescents.

Based on a sampling survey data on overweight and obesity among children and adolescents aged 7-17 in Nanchong City of Sichuan Province, social network analysis, regression analysis, and Bayesian network models were used to analyze the specific impact mechanism of peer relationship networks on overweight and obesity.

Logistic regression showed that high personal popularity(OR=0.001, 95% CI=0-0.026) and high personal activity(OR=0.084, 95% CI=0.009-0.790) were associated with reduced detection of overweight and obesity in children and adolescents, with a relatively stronger correlation between personal activity and obesity. In addition, high household income(OR=19.237, 95% CI=3.799-97.403), high-energy dietary patterns(OR=21.660, 95% CI=1.600-292.904), sitting still for more than 8 hours(OR=10.395, 95% CI=2.013-53.687) increased the risk of overweight and obesity. Long exercise time(OR=0.085, 95% CI=0.019-0.378), both parents have attended college(OR=0.023, 95% CI=0.003-0.169), and mental health(OR=0.030, 95% CI=0.006-0.147) Children and adolescents with high sleep quality(OR=0.006, 95% CI=0.001-0.045) had a lower risk of developing overweight and obesity. The BIC score of the Bayesian network model was -3 954.8. When both individual activity and popularity were set at the 0:1:0 level, the detection probability of overweight and obesity in children and adolescents was 0.126, which was at the lowest level. Adjusting for other intervention variables under the recommended appropriate social network level(i.e. moderate popularity and moderate activity), with the best effect on controlling exercise duration, the likelihood of overweight and obesity in children and adolescents will decrease to 0.044. If social network indicators, dietary habits, exercise duration, psychological and sleep conditions were controlled simultaneously, the detection probability of overweight and obesity was 0, which will achieve the best expected prevention of overweight and obesity detection.

Strengthening social networks, changing lifestyle habits, and improving dietary quality may be important links in the prevention and treatment of obesity in children and adolescents. Therefore, it is necessary to strengthen the responsibility of government departments to accelerate the construction of a comprehensive overweight and obesity prevention and control system.