Increased physical activity reduces weight gain associated with smoking cessation
Increasing physical activity levels to current recommendations helps attenuate weight gain in postmenopausal women after quitting smoking, with the effect more pronounced in combination with improved diet, a study reports.
Researchers followed 4,717 smokers from the Women's Health Initiative for 3 years. Weight and physical activity (summarized as metabolic equivalent task-hours per week) were assessed at baseline and at the year 3 visit.
During the follow-up, 1,282 women quit smoking. Compared with those who continued, quitters gained a mean of 3.5 kg in weight. Specifically, quitters with low physical activity levels showed the highest weight gain (3.88 kg; 95 percent CI, 3.22–4.54), while those with increased physical activity levels (≥15 metabolic equivalent task-hours /week) had the lowest gain (2.55 kg; 1.59–3.52).
The benefit of increased physical activity observed for postsmoking cessation weight gain was more pronounced in women with obesity vs normal weight.
Furthermore, quitters with low physical activity levels at baseline but high levels at year 3 and were also undergoing a dietary modification intervention had a nonsignificant increase in weight (1.88 kg; −0.21 to 3.96) compared with continuing smokers.
While the mechanisms by which smoking influences weight are not fully understood, smoking modulates weight by increasing metabolic rate and decreasing caloric absorption, which is believed to help suppress appetite. Therefore, weight is bound to increase after quitting smoking, with women more likely to gain more than do men. [Am J Public Health 2010;100:1442-1448]