Sex, Socioeconomic and Regional Disparities in BMI Trajectories across Childhood and Their Implications on Underweight and Overweight in Reform-Era China

Linda K. George, Duke University

Based on a longitudinal dataset of the China Health and Nutrition Survey (CHNS), we employ growth curve models to examine sex, socioeconomic and regional disparities in BMI trajectories across childhood and their implications on underweight and overweight in reform-era China. Sex, family income, rural-urban residency and geographical locations (but not for parental education) are found to be significantly associated with differential age trajectories in childhood underweight and overweight from age 6 and age 16. For a specific socio-demographic group, children who have lower prevalence of underweight in the transition from childhood to adolescence (such as boys, children from high-income families, children living in urban areas, northern China or non-western regions) also exhibit higher prevalence of overweight than their counterparts do. Moreover, the age interval during which children are more vulnerable to the increase in underweight is different from that of overweight (age 12 is the tipping point).