title: Why is there gender disparity in the body mass index trends among adults in the 1997-2011 China health and nutrition surveys?
abstract: OBJECTIVE
  Over the past three decades, the prevalence of overweight and obesity in China has increased greatly. Chinese body mass index (BMI) dynamics have shown much greater rates of changes among men, aged 18-45 years, than among women. This study examined the gender difference in the BMI trends and related factors.
  
  
  METHODS
  We used longitudinal data from the China Health and Nutrition Survey collected in 1997, 2000, 2004, 2006, 2009 and 2011. A total of 10,982 participants (N=5339 men and 5643 women) aged 18-45 years were included in the final analysis. Lambda mu sigma method (LMS) was used to describe changes of BMI distribution. Separate sex-stratified multilevel random intercept-slope growth models were applied to examine effects of individual and community variables on BMI trends of Chinese adults.
  
  
  RESULTS
  Male BMI increased by 0.21 kg/m2 overtime, which was larger than female BMI at 0.16 kg/m2. Higher income, drinking and away-from-home food consumption were associated with higher BMI, and these variables were only significant among men. Physical activity (PA) had a negative association for both genders.
  
  
  CONCLUSIONS
  Since different variables resulted in gender disparity in BMI trends among Chinese adults, separate health policies should be developed for men and for women.
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Ouyang
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Su
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Du
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China. Email: zzhangb327@aliyun.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking; D015992:Body Mass Index; D002681:China; D004032:Diet; D015444:Exercise; D005260:Female; D006801:Humans; D007182:Income; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D011446:Prospective Studies; D012737:Sex Factors