Body-mass index and obesity in urban and rural China: findings from consecutive nationally representative surveys during 2004-18.

backgroundIn China, mean body-mass index (BMI) and obesity in adults have increased steadily since the early 1980s. However, to our knowledge, there has been no reliable assessment of recent trends, nationally, regionally, or in certain population subgroups. To address this evidence gap, we present detailed analyses of relevant data from six consecutive nationally representative health surveys done between 2004 and 2018. We aimed to examine the long-term and recent trends in mean BMI and prevalence of obesity among Chinese adults, with specific emphasis on changes before and after 2010 (when various national non-communicable disease prevention programmes were initiated), assess how these trends might vary by sex, age, urban-rural locality, and socioeconomic status, and estimate the number of people who were obese in 2018 compared with 2004.

methodsWe used data from the China Chronic Disease and Risk Factors Surveillance programme, which was established in 2004 with the aim to provide periodic nationwide data on the prevalence of major chronic diseases and the associated behavioural and metabolic risk factors in the general population. Between 2004 and 2018 six nationally representative surveys were done. 776 571 individuals were invited and 746 020 (96·1%) participated, including 33 051 in 2004, 51 050 in 2007, 98 174 in 2010, 189 115 in 2013, 189 754 in 2015, and 184 876 in 2018. After exclusions, 645 223 participants aged 18-69 years remained for the present analyses. The mean BMI and prevalence of obesity (BMI ≥30 kg/m

findingsStandardised mean BMI levels rose from 22·7 kg/m

interpretationIn China, the rise in mean BMI among the adult population appears to have slowed down over the past decade. However, we found divergent trends by sex, geographical area, and socioeconomic status, highlighting the need for a more targeted approach to prevent further increases in obesity in the Chinese general population.

fundingChina National Key Research and Development Program, China National Key Project of Public Health Program, and Youth Scientific Research Foundation of the National Center for Chronic and Noncommunicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention.