title: Age plays an important role in the relationship between smoking status and obesity risk: a large scale cross-sectional study of Chinese adults.
abstract: OBJECTIVE
  To study the role of age plays in the relationship between smoking status and obesity in both Chinese men and women.
  
  
  METHODS
  From Chinese Physical and Psychological Database, participants were divided into non-smokers, current smokers, and former smokers. Body mass index (BMI), waist circumference (WC), fat percentage, fat mass, and fat free mass were measured. The mean, standard deviation and frequency of these indicators were calculated for each age bracket. One-way ANOVA and post-hoc test analyses were used to detect the difference among these three groups.
  
  
  RESULTS
  In men, from 19 to 24 years old, BMI, WC and fat free mass of current smokers were higher than that of non-smokers (P<0.01). However, fat mass and fat percentage of current smokers were lower than that of non-smokers but higher than that of former smokers (P<0.01). From 25 to 34 years old, BMI and fat mass of former smokers were higher than non-smokers and current smokers (P<0.01). In addition, WC and fat free mass of non-smokers were lower than that of current smokers and former smokers (P<0.01). From 45 to older, BMI, WC, fat mass, fat free mass and fat percentage of former smokers were higher than that of current smokers (P<0.01). From 55 to older, BMI, WC, fat mass, fat free mass and fat percentage of current smokers were lower than that of non-smokers (P<0.01). In women, smoking status might not be significantly related to obesity (P>0.05).
  
  
  CONCLUSIONS
  For young men, smoking might have an effect on increasing fat free mass, BMI and WC, and decreasing fat mass and fat percentage. For middle and older men, smoking might have an effect on decreasing fat free mass, fat mass, BMI, WC, and fat percentage. Obesity risk should be paid more attention in smoking cessation programs for those former smokers.
authors.affiliation: Research Center for Translational Medicine, East Hospital, Tongji University Shanghai, China.
authors.forename: Pu
authors.initials: P
authors.lastname: Su
authors.affiliation: Department of Finance, Sam M. Walton College of Business, University of Arkansas Fayetteville, United States of America.
authors.forename: Liu
authors.initials: L
authors.lastname: Hong
authors.affiliation: Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University Shanghai, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University Shanghai, China.
authors.forename: Yi Fan
authors.initials: YF
authors.lastname: Zhao
authors.affiliation: Department of Hematology, Tongji Hospital, Tongji University Shanghai, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
keywords: Smoking; fat percentage; obesity