The 13th World Conference on Tobacco OR Health

Objective: Tobacco use is considered to be inversely associated to weight gain. However, several studies have shown that heavy smokers weighted significantly more than light smokers. Some authors stated that the amount of cigarette smoked could be intimately related to unhealthy behavioral factors such as high alcohol consumption, unhealthy diet, and lack of physical activity. The main objective of the present study was to investigate the gender-specific association between amount of cigarette smoked and body mass index (BMI) increase taking into consideration socio-demographic and lifestyle variables.

Methods: Cross-sectional data from a population-based survey conducted in 16 Brazilian cities, between 2002-2003, was analyzed. A total of 18,830 individuals aged 15 years or older were sampled. A linear regression model was used in the analysis taking into consideration complex design sample (two stage cluster random sampling).

Results: Information on BMI was available for 1,206 light and 153 heavy male smokers, and 1,120 light and 87 heavy female smokers. Crude association between increase of BMI and changing in smoking category was 0.69 (95% CI, -0.81; 2.19) in men and 1.80 (95% CI, 0.53; 3.07) in women. Adjusting for physical activity status, binge drinking, age and educational level, results remained virtually unchanged: 0.17 (95% CI, -1.37; 1.71) for males and 1.97 ( 95% CI, 0.66; 3.28) for female. Notwithstanding the possibility of cross-sectional bias, amount of cigarettes smoked may be related to weight gain in women (but not in men; interaction term P=0.087) due to unhealthy behaviors not considered in this study.