Smoking Habits and Body Weight Over the Adult Lifespan in Postmenopausal Women

Introduction The inter-relationships between smoking habits and weight gain are complex. However, few studies have examined the association of smoking habits with weight gain over the life course. Methods Major smoking parameters and weight gain over time were examined in a large cohort of postmenopausal women aged 50–79 years at enrollment between 1993 and 1998 (N=161,808) and followed through 2014 (analyses conducted in 2016). Cross-sectional analyses were used to assess the association of smoking and body weight at baseline. Retrospective data were used to correlate smoking status with body weight over a 45-year period prior to enrollment. In addition, the association of smoking with weight gain over 6 years of follow-up was examined. Results At baseline, women who had quit smoking prior to enrollment weighed 4.7 kg more than current smokers and 2.6 kg more than never smokers. Former, never, and current smokers all gained weight over the 45-year period from age 18 years to time of enrollment (average age, 63 years): 16.8, 16.4, and 14.6 kg, respectively. In prospective analyses, women who were current smokers at baseline but who quit smoking during follow-up gained more than 5 kg by Year 6 compared with current smokers at baseline who continued to smoke. Among long-term quitters, greater intensity of smoking and more recent quitting were associated with greater weight gain. Conclusions These results suggest that excess weight gain associated with smoking cessation occurs soon after quitting and is modest relative to weight gain in never smokers over the adult lifespan.