Abstract: By comparing the dietary habits and nutrition intake of China’s school-age children in urban areas, migrant children living in urban areas and left-behind-at-home children in rural areas, and their correlations with IBM, the present paper analyzed the reasons for the obesity and malnutrition of different school-age children. Results: Children in urban areas have better dietary habits and nutrition intake than migrant children living in urban areas and left-behind-at-home children in rural areas. Children in urban areas take in too much meat and eggs, which is the primary reason why their BMI is higher than that of migrant children and left-behind-at -home children in rural areas. Children of migrant workers, especially migrant children are becoming more close to children in urban areas in dietary structure, it is possible that they will face new obesity problem.

Key words: School-age Children, Dietary Habit, Nutrition Intake, BMI, Correlational Study