Waist circumference and waist-to-height ratio in Han Chinese children living in Chongqing, south-west China.

OBJECTIVE To derive age- and sex-specific reference values for waist circumference (WC) and waist-to-height ratio (WHtR) for Han Chinese children and adolescents and to establish the prevalence of excess central adiposity in our study population. DESIGN Cross-sectional study of schoolchildren attending randomly selected primary and secondary schools in south-west China in October 2003 and April 2004. Anthropometry was measured using standard procedures. The LMS method was used to construct smoothed WC and WHtR percentile curves. Overweight and obesity were defined by the International Obesity Task Force (IOTF) criteria and the Working Group on Obesity in Children. Excess central adiposity fat was defined by previously published WC cut-points and a WHtR ≥ 0.5. SETTING Primary and secondary schools in Chongqing, south-west China. SUBJECTS A total of 7326 (49.2 % boys) Han Chinese students at 5-17 years old. RESULTS On the basis of the IOTF criteria, 26.4 % of boys were overweight or obese compared with 16.4 % of girls (P < 0.001). WC cut-points identified 31 % of boys and 28 % of girls as having excess central adiposity, whereas using the WHtR criterion, 14.8 % of boys and 5.6 % of girls were identified. Young boys (5-12 years) had a significantly (P < 0.001) higher WHtR than girls. CONCLUSIONS We have constructed WC and WHtR percentile curves for Han Chinese children and adolescents living in Chongqing. Our measurements were based on a student population with a relatively high rate of overweight and obesity. These data will provide a point of reference for future studies measuring the prevalence of overweight and obesity in China.