Many smokers are reluctant to kick the habit because they don’t want to gain additional weight, but a recent study of older women offers hope; it found that even a little bit of exercise after quitting smoking can help keep the pounds off. 
Dr. JoAnn Pinkerton, executive director of the North American Menopause Society, said in a news release:
“Being active after quitting smoking was found to reduce weight gain, regardless of the amount of physical activity before quitting.”
In the study, which tracked more than 4,700 postmenopausal female smokers for 3 years, those who quit smoking during the study period gained 7.7 pounds more than those who continued to smoke. 
However, smokers who increased their levels of physical activity after quitting gained a bit less weight – about 5.6 lbs. And exercise was found to provide an even greater benefit to ex-smokers who had been obese compared with those who were of a normal weight.
Juhua Luo of Indiana University’s School of Public Health and her team of colleagues further discovered that when ex-smokers took up exercise and started eating healthier, they gained only slightly more weight than women who continued to smoke. 
It didn’t appear to matter how much or how little one exercised – any physical activity helped stave off weight gain.
“Although the best results in limiting weight gain after quitting smoking were found in women who engaged in 150 minutes of moderate-intensity activity per week, benefit was also found in less intense activity, such as walking 90 minutes per week at 3 miles per hour.”
So if you’ve been hanging onto your smoking habit because you’re afraid of packing on the pounds, a bit of walking each week and eating healthily could prevent you from having to go up a pants size.