Body mass index percentile curves and cut off points for assessment of overweight and obesity in Shanghai children

Background: Body mass index as a measure for overweight and obesity is widely accepted. There are no references of BMI for Shanghai adolescents and children. This study was undertaken to construct percentile curves of body mass index (BMI) and cut off points for overweight and obesity of children in Shanghai. Methods: The data on birthday, height and weight of the 96 104 children from Shanghai (48 790 boys and 47 314 girls) were measured during 1999 to 2002. The BMI percentile curves for Shanghai children aged 0-18 years were constructed by the LMS method. Based on the recommendations of the International Obesity Task Force (IOTF) and the Working Group on Obesity in China (WGOC), the percentile curves passing through 25 and 30 kg/m 2 or 24 and 28 kg/m 2 at age of 18 were established as overweight and obesity cut off points for Shanghai children. Results: The age and sex specific BMI percentile curves of Shanghai children were constructed. The BMI in childhood changes substantially with age. The medians at birth are 13.7 and 13.4 kg/m 2 for boys and girls, respectively, and increase to 18.3 and 17.8 kg/m 2 at age of