摘要:With the development of social economy, people’s living standard has been improved. Malnutrition among Chinese adolescents is gradually decreasing, but is still widespread in some rural areas, especially among left-behind adolescents. We compared the nutritional status of rural left-behind and urban migrant middle school students and analysed its influencing factors to provide a scientific basis for the formulation of government policies for health promotion. Stratified cluster random sampling was employed. Participants were 513 urban migrants and 440 rural left-behind middle school students aged 12-15 years. The underweight detection rates of the rural left-behind group (boys: 18.6%, girls: 15.4%) were substantially higher than that of the urban migrant group (boys: 9.2%, girls: 3.7%), and the overweight/obesity detection rates of the urban migrant group (boys: 40.1%, girls: 21.2%) were substantially higher than that of the rural left-behind group (boys: 10.2%, girls: 6.6%). The prevalence of underweight among rural left-behind middle school students in Shangrao was correlated with parents’ education level and monthly household income, and the prevalence of overweight/obesity among urban migrant middle school students in Shanghai was correlated with physical activity.