Social determinants of childhood obesity in Shanghai, China: a cross-sectional child cohort survey

Abstract Background In the past 20 years, cities in China have undergone unprecedented economic and social development, and chronic health conditions have increased correspondingly. Until now, research in China addressing the notable rise in childhood overweight and obesity has mainly relied on public health data with basic descriptions of these trends. This study took advantage of a new dataset focused on the wellbeing of children in Shanghai to examine the relation between childhood overweight and obesity at school entry and family sociodemographic factors. Methods We used the 2014 Child Well-Being Study of Shanghai, China, a study modelled on other international child cohort studies. The sample is of roughly 2000 children aged 7 years at the time of the survey. We used logistic regression to estimate odds ratios of overweight and obesity by income tertile, parental education, and hukou status. We used the overweight and obesity cutoff points of the US Centers for Disease Control and Prevention to compare our results with US data, but we also compared our data with established international and Chinese standards for overweight and obesity. All results were stratified by sex, and we also included sociodemographic factors, health insurance status, and health behaviours in the models. Findings High rates of childhood overweight (36%) and obesity (21%) in Shanghai, China, were reported—rates that are higher than those in the USA. Multivariate analysis showed that our sample has a reverse income and education gradient in childhood overweight and obesity—but only for boys. High household income and high parental education are associated with increased rates of childhood overweight and obesity for boys, but no pattern by socioeconomic status exists for girls. Girls from urban families are also more likely to be overweight or obese than those from rural families. Interpretation Our results highlight the importance to address social determinants in shaping health policies targeted at improving children's health and wellbeing in China. Funding None.