Comprehensive school-based intervention to control overweight and obesity in China: a cluster randomized controlled trial

Abstract

Background and objectives: With prevalence of childhood obesity increasing rapidly, developing of effective and sustainable intervention strategies is becoming more and more important for the prevention of childhood obesity in China. A trial was developed to evaluate the effect of comprehensive school-based intervention on childhood obesity.

Methods and study design: A multi-center cluster randomized controlled trial was conducted among urban children (n=9,867) aged 6-13 years in 38 primary schools from six large cities. Comprehensive intervention, nutrition education and physical activity interventions were carried out among children. Nutrition education was also targeted towards teachers, parents and health workers in intervention schools. The program was implemented for 2 semesters from May 2009 to May 2010.

Results: The combined prevalence of overweight and obesity increased by 1.5 percent (22.7% vs 24.2%, p<0.001) in control group while 0.2 percent in comprehensive intervention group (23.6% vs 23.8%, p=0.954) after intervention (p=0.067). The effect was significantly stronger among girls than boys (-1.4% vs -0.9%, p=0.028). A significant intervention effect was found on BMI for -0.3 kg/m2 (95% confidence interval (CI): -0.4, -0.2; p<0.001), BMI z scores for -0.14 (95% CI: -0.18, -0.11; p<0.001)，body fat for -0.8 percent (95% CI: -0.9, -0.6; p<0.001), waist circumference for -0.5 cm (95% CI: -0.6, -0.3; p<0.001), blood serum glucose for -0.20 mmol/L (95% CI: -0.24, -0.16; p<0.001) and cholesterol for -0.32 mmol/L (95% CI: -0.34, -0.30; p<0.001).

Conclusions: We observed moderately significant effects on combined prevalence of overweight and obesity, BMI, BMI z scores, waist circumference, percentage body fat, glucose and lipid for a comprehensive school-based intervention of childhood obesity in China.