Nutrition and physical activity related school environment/policy factors and child obesity in China: a nationally representative study of 8573 students in 110 middle schools.

BACKGROUND

Obesity is a serious threat to global health. School is a key setting for obesity intervention. Research on school risk factors for child obesity is limited in developing countries.

OBJECTIVES

To examine regional variations in obesity and school environments/policies and their associations among students in China.

METHODS

Analyses were based on the first nationally representative sample of 8573 9 graders in 110 middle schools from 28 regions across China. Multilevel models tested associations between school factors and child self-reported weight outcomes and by school urbanicity setting (urban, rural).

RESULTS

Overweight/obesity rate is higher among boys and in urban areas. Schools in rural areas, or less developed regions, promote longer on-campus life, as is indicated by the presence of school cafeterias, night study sessions and longer class hours. Multilevel models show that (i) school cafeterias (OR = 2.53, 95% CI = 1.35-4.75) and internet bars close to school (OR = 1.63, 95% CI = 1.15-2.30) are associated with increased overweight/obesity risk in rural areas, especially for boys; (ii) school night study sessions are associated with lower overweight/obesity risk (OR = 0.69, 95% CI = 0.50-0.96) in rural areas.

CONCLUSIONS

China has large regional disparities in school environment/policies related to nutrition and physical activity. Some school factors are associated with students' weight status, which vary across gender and areas. Future school-based interventions should attend to diverse regional contexts.