Smoking cessation and obesity: What are the short-term effects and long-term gains?

Background: While public health interventions target smoking cessation, studies have shown that concerns about weight gain prevent quitting. Current research on the relationship between smoking cessation and obesity are restricted to smaller samples and lack generalizability.

Study Question: Our study examined the relationship between smoking status and obesity and the length of time since smoking cessation and current obesity.

Methodology: Data from the 2009 and 2010 national Behavioral Risk Factor Surveillance Surveys (BRFSS) was used (age≥30, n=785,475). The outcome variable was obesity (BMI≥ 30) and independent variables were smoking status (current, former, and never) and length of time since quitting (0-6 months, 6months-1 year, 1-5 years, 5-10 years, 10+ years). Multivariable regression analyses were performed, stratified by gender and adjusted for potential socio-demographic risk factors. Results: The prevalence of obesity was 29%, with significantly higher prevalence among males (30.3%) than females (28.0%). The likelihood of being obese among former smokers was 20% in males and 16% in females. Time since smoking cessation was significantly associated with current obesity and showed an inverse U-shaped association. The odds of being obese peaked within one year after smoking cessation in both genders, with higher odds among males (OR=1.31; 95% CI: 1.05-1.63) than among females (OR=1.21; 95% CI: 1.03-1.44), but declined afterwards with time. Conclusion: Our results indicate weight gain after smoking cessation is short-term, predominantly higher in males and dissipates with time among both genders. Successful long-term smoking cessation interventions should include weight maintenance programs to prevent relapse.