Economic development and the nutritional status of Chinese school-aged children and adolescents from 1995 to 2014: an analysis of five successive national surveys

Abstract

Socioeconomic development is widely regarded as contributing to improved nutrition in children. We aimed to assess the association between socioeconomic indicators and child and adolescent nutritional status, and the differences in this association between urban and rural areas. We extracted data from the 1995, 2000, 2005, 2010, and 2014 cycles of the Chinese National Survey on Students' Constitution and Health. We analysed these data for three nutritional outcomes-stunting, thinness, and overweight and obesity-in children and adolescents aged between 7 and 18 years, as defined by WHO standards and classifications. We included three socioeconomic indicators-gross domestic product (GDP) per capita, Engel coefficient (the proportion of household income spent on food), and urbanisation ratio-at both national and subnational levels for each survey year. We used logistic regression models to estimate the association between socioeconomic indicators and child nutritional status, and used prevalence odds ratios (ORs) to assess the urban-rural disparity for nutritional status over time. We also used generalised additive models to evaluate differences in associations between socioeconomic and nutritional status between urban and rural areas. We included 1 054 602 participants (204 932 in 1995; 209 167 in 2000; 225 213 in 2005; 208 136 in 2010; 207 154 in 2014) with complete records on age, sex, nationality, height, and weight in the final analyses, and the final dataset contained 29 provinces (Hong Kong, Macau, Taiwan, Chongqing, and Tibet were excluded) with complete socioeconomic indicator information and student nutritional status information. From 1995 to 2014, the mean stunting prevalence in Chinese children and adolescents decreased from 8·1% (95% CI 8·0-8·2) to 2·4% (2·4-2·5), and the mean thinness prevalence declined from 7·5% (7·4-7·6) to 4·1% (4·0-4·2). Overweight and obesity mean prevalence increased from 5·3% (5·2-5·4) to 20·5% (20·4-20·7). We observed an inverse association between socioeconomic indicators and mean stunting and thinness prevalence, and found a positive association between socioeconomic indicators and overweight and obesity prevalence. The urban-rural disparity in nutritional status gradually diminished, with the prevalence ORs approaching equivalence over time. More rapid improvement of socioeconomic indicators was associated with changed nutritional status in children and adolescents, but with differences across urban and rural settings. The association between socioeconomic status and overweight and obesity was stronger in rural than in urban areas. Improvements (reductions) in the Engel coefficient were accompanied by a greater reduction of stunting and thinness in rural than in urban areas. Although socioeconomic development has been accompanied by continued improvements in stunting and thinness, a marked increase has occurred in overweight and obesity in Chinese children and adolescents, particularly in rural areas. There is a pressing need for policy actions to extend beyond an emphasis on economic growth alone, and to focus on promotion of healthy diets and physical activity. National Natural Science Foundation, The Research Special Fund for Public Welfare Industry of Health of the Ministry of Health of China, and China Scholarship Council.