Difference of body mass index stratified by the period of smoking cessation from a cross-sectional study

Background. Smoking cessation is associated with subsequent obesity. This study was designed to clarify the duration of weight gain lasted after cessation of smoking. Methods. A total of 2,511 male subjects aged 25-62 years participated in an annual health examination at their workplace. The relationship between body mass index (BMI) and the period since cessation of smoking was evaluated by multiple logistic regression analysis using age, drinking status, and physical activity as covariates. Results. Percentages of current and nonsmokers with BMI not <25 kg/m(2) were 23.3 and 27.5%, respectively. Percentage of ex-smokers with BMI not <25 and with periods of 0-1 year, 2-4 years, 5-7 years, 8-10 years, and >10 years since giving up smoking were 37.5, 27.9, 43.2, 29.4, and 29.8%, respectively. Among ex-smokers with the previously mentioned periods after giving up smoking, odds ratios (ORs) and 95% confidence intervals (95% CIs) of BMI not <25 kg/m(2) were 1.58 (0.90-2.76), 1.01 (0.57-1.81), 2.01 (1.08-3.71), 1.10 (0.59-2.05), and 1.11 (0.75-1.65), respectively. ORs and 95% CIs of BMI with not <25 kg/m(2) on current smokers were 0.80 (0.66-0.97). Conclusions. Obesity due to smoking cessation was observed in subjects within the period from 5 to 7 years after stopping smoking; obesity due to smoking cessation is not a permanent phenomenon. (C) 2004 IMSS. Published by Elsevier Inc.