To explore the current situation of sleep duration among primary and secondary school students and its relationship with overweight and obesity, providing a theoretical basis for the prevention and control of overweight and obesity among primary and secondary school students.

A stratified cluster sampling method was adopted to conduct a questionnaire survey and physical examination among 10 120 primary and secondary school students in Xuchang City, Henan Province from September to December 2024. Analysis of variance, χ² test, logistic regression analysis, restricted cubic spline(RCS) model and other statistical methods were applied to explore the association between sleep duration and overweight/obesity in primary and secondary school students.

There were 1 625 people who were overweight (accounting for 16.06%)and 1 580 people who were obese (accounting for 15.61%). The rates of overweight and obesity among males were higher than those among females (χ²=191.19, P<0.001). The obesity rate among primary school students was higher than that among junior high school and senior high school students (P<0.0167). The obesity rate of primary and secondary school students who consumed sugar-sweetened beverages at least once a day on average in the past 7 days was higher than that of those who never consumed them (P<0.0167). The rates of overweight and obesity among primary school students with severely insufficient sleep were higher than those among students with sufficient sleep (χ²=13.060, P=0.011). The results of logistic regression analysis showed that compared with students with sufficient sleep, severely insufficient sleep during the primary school stage was a high-risk factor for obesity (OR=1.40, 95% CI: 1.03-1.92). The results of RCS analysis indicated that there was a nonlinear dose-response relationship between sleep duration and obesity rate among primary school students (P_{total trend}<0.001, P_non-linear=0.039),and the optimal sleep duration was 9.50 hours.

The influence of sleep duration on overweight and obesity varies by educational stage. Controlling sleep time to 9.5 hours during the primary school stage is a key window for preventing overweight and obesity. During the secondary school stage, a comprehensive intervention strategy that emphasizes both academic pressure management and a healthy lifestyle should be adopted to reduce the occurrence of overweight and obesity.