Prevalence and Trends in Obesity among China's Children and Adolescents, 1985-2010

Objectives: We examined the prevalence of and trends in obesity among children and adolescents in China (1985-2010). Methods: We used data from the 1985, 1991, 1995, 2000, 2005, and 2010 Chinese National Surveys on Students' Constitution and Health (CNSSCH). The CNSSCH is a national survey of physical fitness and health status in Chinese students that uses multistage stratified sampling of 31 provinces and municipalities. A subject was considered obese or overweight if weight-for-height exceeded the 20% or 10% of standard weight-for-height. The standard weight-for-height was the 80th percentile for sex-and age-specific growth charts. Results: The age-adjusted prevalence of obesity and of overweight and obesity combined was 8.1% (95% CI, 8.0-8.3%) and 19.2% (95% CI, 19.1-19.4%) among children and adolescents 7-18 years in age. Obesity was more likely to be present among children or adolescents who were male (RR, 1.93; 95% CI, 1.90-1.97), urban (RR, 1.99; 95% CI, 1.95-2.02), or 10-12 years (RR, 1.43; 95% CI, 1.40-1.46). Trend analyses of the 25-year period revealed a significant increasing trend in males (RR, 1.59; 95% CI, 1.58-1.60) and in females (RR, 1.49; 95% CI, 1.48-1.50). The rate of increase in obese or overweight prevalence was highest in boys from rural areas (9% annual increase). Conclusions: During 1985-2010, there was a significant and continuous increase in the prevalence of obesity in children and adolescents. Obesity is epidemic in China, but may be reduced with evidence-based interventions (e.g., school intervention programs).