OBJECTIVETo determine the current prevalence of overweight and obesity among children and adolescents (2-18 years) in Beijing and its distribution by age, gender and urban-rural residence.

METHODSAs part of the Beijing Child and Adolescent Metabolic Syndrome Study, a stratified cluster representative sample of 23,422 children aged 0-18 years was selected. Anthropometric measures including weight and height were collected from 21,198 subjects aged 2-18 years from April to October in 2004. Overweight and obesity were defined according to body mass index [BMI, weight(kg)/height(m2)] cutpoints. For national and international comparisons, three sex-age-specific BMI criteria were used:1) The BMI cutoffs recommended by the Chinese Working Group on Obesity for Children (WGOC) aged 7-18 years; 2) The US 2000 CDC Growth Charts (CDC 2000) frac 34, the 85th and 95th percentiles; 3) The International Obesity Task Force (IOTF) reference.

RESULTSThe overall combined prevalence of overweight and obesity was 18.6% with obesity as 8.1% based on the CDC 2000 criteria, The figures were 17.4% and 5.1% based on the IOTF criteria. According to the WGOC criteria, the combined prevalence of obesity was 20.9% and 8.9% in children aged 7-18 years. The combined prevalence was higher in school-age children (6-18 years) than in preschool-age children (19.8% vs. 14.8%, based on the CDC 2000 criteria). Among school-age children, the prevalence was higher in boys than in girls (26.7% vs. 16.5%), in urban than in rural areas (27.0% vs. 15.9%). However, these differences were not observed in preschool-age children. It was estimated that approximately 450 000 children from 2 through 18 years of age,were overweight or obesity in Beijing.

CONCLUSIONData from our study indicated that one fifth of the children and adolescents in Beijing were under overweight or obesity situation which was the highest in the nation. Obesity among children and adolescents in Beijing had already become a serious public health problem which deserved greater attention.