Emerging Disparities in Overweight by Educational Attainment in Chinese Adults (1989–2006)

OBJECTIVE: We test whether a disparity by socioeconomic status (SES) (represented by educational attainment) in overweight has emerged among men or women during a recent 17 year period in China. METHODS: Data from the China Health and Nutrition Survey (CHNS), a panel study including 7,314 women and 6,492 men, are used to longitudinally track the BMI and odds of overweight by educational attainment among Chinese adults (baseline age 18–50) from 1989 to 2006 to determine whether individuals of low (<primary school) versus high (>secondary school) educational attainment experienced a disproportionately faster increase in BMI or odds of overweight (BMI≥25) over time. The unadjusted mean BMI and prevalence of overweight by education are presented. Sex-stratified, random-effects models are used to estimate the associations and interactions by birth cohort are included. FINDINGS: Overweight prevalence has doubled for women and tripled for men. Among women in 1989, the odds of overweight was not different for those of high versus low educational attainment; however, by 2006, odds of overweight were significantly lower for those with the highest education in both the younger (OR= 0.22; CI 0.11, 0.42) and older (OR=0.27; CI 0.10, 0.72) birth cohorts. The reverse trend is seen for men, who also begin with no difference in odds of overweight by SES, but by 2006, the odds ratio for the highest versus lowest education group was OR 3.4 (CI 1.82, 6.18). CONCLUSIONS: Over 17 years, low SES has become associated with higher BMI and odds of overweight among Chinese women, while high SES remains a risk factor for overweight among Chinese men.