Quitting smoking results in minimal weight gain

The declining rate of smoking is unlikely to be a major contributor to the recent increases in the incidence of obesity. While quitting smoking might cause some people to gain weight, the amount gained will probably be small, reports a new study in Health Services Research.

The amount of weight likely to be gained varies depending on whether you are young or old, male or female, and if you are already overweight, said Panagiotis Kasteridis, Ph.D., a post-doctoral research associate in the Department of Agriculture and Resource Economics at the University of Tennessee.

Kasteridis and colleague Steven T. Yen, Ph.D., evaluated data from the 2004-2005 and 2009-2010 Behavioral Risk Factor Surveillance Survey, from 349,000 current and former smokers who answered questions about smoking, health behaviors, and their body mass index (BMI).

The study found that quitting smoking was associated with a small increase in BMI and that this effect increased over time. Young women gained about 2.3 percent in BMI within a month after quitting smoking, up to a maximum of 5.2 percent between 3 and 6 months after quitting.

This pattern was similar in young men and older women and men, although the maximum increases took longer in those groups. The largest BMI increase occurred in older women, whose BMI increased by more than 8 percent, or about 13 pounds, over 10 years after quitting.

"The results are particularly encouraging for young individuals. The effects of quitting on BMI are considerably lower among young men and women," Kasteridis said. "The price that must be paid, in terms of weight gain, to enjoy the health benefits of smoking cessation is trivial."

"Our results also suggest that the effects of smoking cessation in the overweight and obese population – the groups that may be more concerned about gaining weight – are modest and similar to those in the normal weight population," Kasteridis reported.

This study is valuable because it looked at the effects of stopping smoking on several different categories of people, said Norman Edelman, M.D., chief medical officer at the American Lung Association. "The bottom-line finding is that the increase is quite small, especially in an obese person."

"Smoking cessation is clearly of great importance in health," Edelman said. "It improves health outcomes and does not seem to add enough weight to make a significant difference."