Smoking and body weight: evidence from China health and nutrition survey

BACKGROUND: The effects of cigarette smoking on body weight remain inconclusive. This study evaluated this relationship using the latest data from China, the largest consumer market of tobacco in the world, which is also experiencing a steady increase in patients with obesity. METHODS: Using data obtained from China Health and Nutrition Survey (CHNS) 1991–2011, Logit Model and Two-Stage Residual Inclusion (2SRI) estimation were applied. Local tobacco yield was considered as instrument variable for smoking behavior and corrected for endogeneity. RESULTS: Smoking increased the likelihood of being underweight by 0.9 % and healthy weight by 5.3 %, while the likelihood of overweight and obesity decreased by 6.5 %, of which obesity reduced by 5.1 %. After correcting for endogeneity, the results were consistent and stronger. Cigarette smoking increased the likelihood of being underweight by 2.7 % and healthy weight by 12.7 %, while it decreased the likelihood of overweight and obesity by 13 %, of which obesity reduced by 10 %. CONCLUSION: Smoking induced heterogeneous effects on body weight. Smoking had a positive effect on underweight and healthy weight, while a negative effect on overweight and obesity. Tobacco control interventions may lead to weight loss among healthy subjects, while the effects on obese subjects were not obvious as expected.