Mild weight gain after quitting smoking outweighed by cessation's benefits

Weight Gain After Quitting Smoking Usually Mild, Harmless
Nicotine is an anorexigen, or appetite suppressant. This "benefit" of cigarette smoking is no secret, certainly not to teenage girls, who in surveys report smoking to stay thin. Even among women smokers over age 40, more than half said they would not quit smoking if it meant they would gain more than one pound.
Unfortunately for us in the business of encouraging smoking cessation, most people who quit smoking do gain weight, especially in the first year after quitting. The average weight gain one year after quitting smoking is about 10 pounds, but results vary: as many as 20% lose weight, while about one in seven quitters gain more than 20 pounds. (What happens to that weight later? Read on.)
If these surveys reflect reality, many people considering quitting smoking are more concerned with how they look in a bathing suit or at the gym than their heart health. But a new study in JAMA could provide weight-leery smokers with extra motivation to quit. Carole Clair et al analyzed data from more than 3,000 children of the Framingham heart study participants, and found that those who quit smoking only gained a few pounds on average. Better yet, any extra weight they carried did not increase their overall risk for heart attacks and strokes.
As long as the net weight gain was less than 10 pounds, the benefits of quitting smoking far outweighed any health impact from weight gained while quitting. Former smokers cut their risk of cardiovascular events in half, and this appeared to hold true even for people who gained a little weight and also developed diabetes.
After 4+ years out from their last cigarette, in this study:
About 39% lost weight from their initial smoking weight;
About 45% gained less than 11 pounds (5 kg);
Only ~16% had gained more than 11 pounds (5 kg).
However, people who gained more than 10 pounds had significantly increased risk of heart disease, with obesity reducing the benefits of smoking cessation.
Both smoking and obesity are bad for the heart, and the combination of the two is even worse for cardiovascular health. But this study further confirms smoking's place as the greater of two evils. A few extra pounds are a small price to pay for the health victory gained by getting free of cigarettes.
Carole Clair et al. Association of Smoking Cessation and Weight Change With Cardiovascular Disease Among Adults With and Without Diabetes. JAMA 2013; 309(10):1014-1021.