Smokers' physical activity and weight gain one year after a successful versus unsuccessful quit attempt

Abstract

Objective: To examine whether smokers' physical activity is related to weight change following a quit attempt.

Method: Data were analyzed for participants (n=683) of a randomized controlled trial comparing the efficacy of different smoking cessation pharmacotherapies (Wisconsin, 2005-2008). Activity (assessed via pedometry) and body weight were measured in the days surrounding the quit day and again one year later, at which time 7-day point-prevalence abstinence from smoking was assessed. We examined the effects of quitting, physical activity, and their interaction, on a one-year weight change with relevant covariate adjustment.

Results: Participants were predominantly female (57%), 46 ± 11 years of age (mean ± SD), and took 7544 ± 3606 steps/day at baseline. Of those who quit, 87% gained weight. A main effect was found for quitting (p<0.001), but not physical activity (p=0.06). When pattern of activity was examined across the 1-year study period, quitters who decreased their physical activity had significantly greater weight gain than quitters who increased their physical activity (p<0.01) or maintained a high level of activity (p=0.02).

Conclusion: Physical activity is associated with an attenuation of the weight gain that often occurs after quitting smoking.

Keywords: Obesity; Physical activity; Smoking cessation; Walking; Weight gain.

Figure 1

Weight gain (mean ± SE) from baseline (Y0) to year 1 (Y1) by Y1 quit status (point-prevalence abstinence) and quartile of “averaged” mean steps/day (the mean of the Y0 and Y1 scores). Data analyzed for participants from a randomized controlled trial comparing the efficacy of different smoking cessation pharmacotherapies (Wisconsin, 2005-2008). Adjusted for age, sex, Y0 weight, education, income, cigarettes/day, and caloric intake. Steps/day for quartiles 1 through 4 respectively are: < 5341, 5341-7137, 7138-9721, and >9721 steps/day. p_interaction=0.63, p_quit≤0.001, p_steps=0.06

Figure 2

Weight gain (mean ± SE) from baseline (Y0) to Year 1 (Y1) by Y1 quit status (point-prevalence abstinence) and steps/day status (low or high) at Y0 and again at Y1. Data analyzed for participants from a randomized controlled trial comparing the efficacy of different smoking cessation pharmacotherapies (Wisconsin, 2005-2008). Adjusted for age, sex, Y0 weight, education, income, cigarettes/day, and caloric intake. Steps/day were split at the median value at Y0 (7161 steps/day) and at Y1 (7250 steps/day), and participants were classified as low or high at each time point. p_interaction=0.33, p_quit≤0.0001, p_steps=0.002.