Regional, socioeconomic and urban-rural disparities in child and adolescent obesity in China: a multilevel analysis

Aim: To study socio-demographic patterns of obesity in Chinese children and adolescents. Methods: Data came from the 2005 cycle of the Chinese National Survey on Student's Constitution and Health. In all, 231 326 subjects aged 7-18 years, distributed across 622 schools and 30 provinces, were analysed. Multilevel modelling was used to estimate variations at individual, school area and province levels. Results: The prevalence of obesity varied enormously across different areas. Young people living in high socioeconomic and urban areas had higher body mass index (BMI) and higher odds of overweight and obesity than those living in lower socioeconomic and rural areas. Subjects living in provinces with a higher standard of living, as indicated by less perinatal mortality, lower Engel coefficient, and higher personal expenditure on health had higher BMI and higher odds of overweight and obesity than those living in less affluent provinces. An interaction between gender and urbanicity revealed that boys in urban areas were especially prone to obesity. Conclusion: In contrast to most present-day high income countries, obesity among young people in China is associated with affluence and urban residence. Intervention and strategy for obesity prevention should be targeting high socioeconomic families in urban areas, perhaps with particular focus on boys.