[Trends in body mass index and waist circumference of children and adolescents aged 6-17 in China from 1982 to 2016].

To analyze the trends and demographic characteristics of body mass index and waist circumference changes in children and adolescents aged 6-17 in China. Using the survey data of 6-17 children and adolescents from five rounds of national nutrition surveys/surveillance from 1982 to 2016, excluding those with missing demographic information and key indicators such as body mass index and waist circumference. A total of 185 491 children and adolescents aged 6-17 were included. Complex weighting method were used to adjust body mass index, waist circumference, obesity rate, and high waist circumference rate. The distribution curves and percentile variation curves of body mass index and waist circumference for Chinese children and adolescents aged 6-17 in different years by gender were drawn. The trends of the prevalence of different types of obesity based on the occurrence of body mass index obesity and high waist circumference obesity were described. From 1982 to 2016, the overall distribution curves of body mass index and waist circumference for children and adolescents aged 6-17 in China showed a peak decrease, a trend of rightward shift, and an accelerating increase over time. The average body mass index of boys and girls increased by 1.80 and 1.23 respectively over the decades, and the average waist circumference increased by 1.40 cm and 1.05 cm respectively from 2012 to 2016. The body mass index and waist circumference levels of boys in all age groups were generally higher than those of girls. The higher increase of body mass index and waist circumference were both observed among boys and girls with higher values than those with lower values. The main type of obesity among children and adolescents in China was high waist circumference obesity, and there were population differences in the ratios of different types of obesity. The main type of obesity in boys and children aged 7-11 was a mixture of body mass index obesity and high waist circumference obesity. The main type of obesity among girls and adolescents aged 12-17 was high waist circumference obesity alone, but the proportion of mixed obesity increased year by year. Body mass index obesity alone had the lowest proportion among all populations. From 1982 to 2016, the body mass index and waist circumference of children and adolescents aged 6-17 in China showed a significant increase trend, with gender and age differences.