[Analysis on the trend of overweight and obesity of children and adolescents in 9 provinces of China from 1991 to 2015].

Objective: To analyze the trends of overweight and obesity of children and adolescents in 9 provinces of China from 1991 to 2015. Methods: A total of 14 888 children and adolescents aged 6-17 years with complete data were selected from the China Health and Nutrition Survey from 1991 to 2015. The definitions of overweight and obesity were defined using the international body mass index (BMI) cut-offs for child overweight and obesity established by the International Obesity Task Force in 2000 (hereinafter referred to as 'IOTF Standard'), the growth reference for school-aged children and adolescents established by the World Health Organization in 2007 (hereinafter referred to as 'WHO Standard'), the BMI cut-offs for screening overweight and obesity in Chinese children established by Li Hui et al. in 2009 (hereinafter referred to as 'Expert Standard'), and the screening thresholds for overweight and obesity in Chinese school-age children and adolescents released by the National Health and Family Planning Commission in 2018 (hereinafter referred to as 'Industry Standard'). Multivariable linear regression model was used to examine the trends in BMI values from 1991 to 2015, and multivariable logistic regression model was used to examine the trends in the prevalence of overweight and obesity from 1991 to 2015. Results: After adjusting for the age, sex and region, BMI values increased from 17.26 kg/m(2) in 1991 to 18.72 kg/m(2) in 2015 (P value for trend <0.001). The prevalence of overweight defined by the IOTF Standard, WHO Standard, Expert Standard, and Industry Standard increased from 4.06%, 5.37%, 5.16%, and 4.27% in 1991 to 13.58%, 16.23%, 13.30%, and 11.70% in 2015, respectively (all P values for trend <0.001), and the prevalence of obesity increased from 1.02%, 1.86%, 2.24%, and 2.41% in 1991 to 7.45%, 10.75%, 12.08%, and 12.74% in 2015, respectively (all P values for trend <0.001). Conclusion: The BMI values and prevalence of overweight and obesity increased significantly in Chinese children and adolescents from nine provinces from1991 to 2015.目的： 分析1991—2015年中国9个省份儿童青少年超重和肥胖率的变化趋势。 方法： 采用1991—2015年9次"中国健康与营养调查"数据，选取资料完整的14 888名6~17岁儿童青少年为研究对象。超重和肥胖分别采用2000年国际肥胖工作组（IOTF）制定的全球儿童超重和肥胖标准（IOTF标准）、2007年世界卫生组织（WHO）制定的学龄儿童青少年生长参照标准（WHO标准）、2009年李辉等制定的儿童超重肥胖筛查体重指数界值（专家标准）及2018年原国家卫生和计划生育委员会发布的学龄儿童青少年超重与肥胖筛查界值（行业标准）进行判定。采用多元线性回归模型分析1991—2015年儿童青少年体重指数变化趋势，采用logistics回归模型分析1991—2015年超重和肥胖率的变化趋势。 结果： 调整年龄、性别和地区后，体重指数由1991年（2 363名）的17.26 kg/m(2)上升至2015年（1 060名）的18.72 kg/m(2)（P(趋势)<0.001）。根据IOTF标准、WHO标准、专家标准和行业标准，超重率分别由1991年的4.06%、5.37%、5.16%、4.27%增长至2015年的13.58%、16.23%、13.30%、11.70% （P(趋势)<0.001），肥胖率分别由1991年的1.02%、1.86%、2.24%、2.41%增长至2015年的7.45%、10.75%、12.08%、12.74%（P(趋势)<0.001）。 结论： 1991—2015年，我国9个省份儿童青少年体重指数水平、超重和肥胖率均呈逐年增加趋势。.