New evidence on the effect of smoking on the obesity risk among adults, Findings from the China Health and Nutrition Survey (CHNS, 1991-2015)

Background: To estimate the approximately causal effects of smoking on the obesity risk among Chinese adults. Methods: Using China Health and Nutrition Survey (CHNS) datasets from 1991 to 2015, this study consisted of 35,907 males and 39,441females aged 18-65 years. Using ordinary-least squares and probit models to investigate the effects of smoking on risk of obesity among Chinese adults. Results: Male current smokers had a higher dietary energy intake (23.28 unit), percentage of dietary energy intake from fat (0.47 unit), physical activity (9.96 unit), drinking (0.61 unit) but less likely to be general obesity (0.17 unit) and abdominal obesity (0.12 unit) than nonsmokers. Female current smokers less likely to be general obesity (0.03 unit) and abdominal obesity (0.12 unit) than nonsmokers. Male heavy smokers (>25 cigarettes/d) had higher dietary energy intake (89.65 unit), physical activity (15.31 unit), drinking (0.08 unit) and more likely to be general obesity (0.18 unit) and abdominal obesity (0.10 unit) than other smokers. Conclusions: Compared with nonsmokers, current smokers had lower probability of being general obesity and abdominal obesity among Chinese adults regardless of gender. Male heavy smokers increased the risk of obesity than other smokers. These findings may improve the understanding on how cigarette smoking affects fat distribution and provide scientific evidence regarding intervention in smoking and obesity, especially for male heavy smokers