NEW YORK, May 12 (Reuters Health) -- Physical activity and moderate alcohol consumption can help former smokers limit weight gain associated with quitting, Israeli researchers report.
The study results also suggest that while the increased rate of weight gain after smoking cessation may last for up to 4 years, the excess weight gained may be retained for 6 years or more. The report is published in the May issue of the American Journal of Public Health, the journal of the American Public Health Association.
Researchers led by Dr. Paul Froom of the Sackler School of Medicine in Tel Aviv, Israel, followed 1,209 male factory workers for 2 to 4 years to estimate the risk of weight gain after quitting smoking, and to identify factors that could influence this risk.
The team used body mass index (BMI) -- a formula that estimates weight in kilograms in relation to height in meters squared -- to measure obesity.
Smoking habits were classified into four groups: current smokers, never smokers, those who quit smoking before entry into the study, and those who quit smoking after entry into the study.
The investigators report that average BMI was highest among those who had stopped smoking before the study began, and lowest among current smokers.
They also found that the rate of weight gain was highest during the first 2 to 4 years after smoking cessation. Analysis of data from the workers who stopped smoking before the study began suggested that this weight gain was retained for at least 6 years.
"Cessation of smoking after entry (into the study) predicted an increased gain in BMI," write Froom and colleagues. But factors such as older age, a higher BMI at entry, sports activity, and moderate alcohol consumption helped to slow this gain.
The research team notes that attempts to combine smoking cessation with weight reduction were "disappointing." Their findings suggest that a smoker of normal weight had a 5.9% chance of becoming obese if he continued smoking, but a 9.6% chance if he stopped smoking. In contrast, for an obese smoker, the chance of losing weight was 16.4% if he continued smoking, "but none if he stopped smoking."
SOURCE: American Journal of Public Health 1999;89:718-722.
