Putting down that cigarette may cost you your shapely figure, but only if you were a heavy or obese smoker to begin with, a recent study suggests.

Published in the International Journal of Obesity this past July, the authors of the study sought to better understand one of the most commonly reported side-effects of quitting smoking — weight gain.

"Many smokers are concerned about gaining weight after quitting smoking and this can be a barrier for them when they are considering whether or not to make a quit attempt," said lead author Dr. Susan Veldheer, a dietitian at the Penn State College of Medicine, in a statement released by the college. "Being able to easily identify smokers who may gain more weight when they quit is important so that we can work with patients to tailor their treatment plan."

To that end, they analyzed a decade’s worth of data (2003 to 2012) from 12,204 people over the age of 36 who participated in the National Health and Nutrition Examination Survey, an annual tally of Americans’ health and nutritional status. They specifically keyed on the participants’ reported smoking habits and weight. "People tend to put on some weight over time and everyone in the study gained weight. The non-smokers gained about a pound a year for 10 years," said Veldheer.

After controlling for various factors, they found that those who had quit smoking one to ten years prior to the survey reported around the same amount of weight gain in the past decade as those who continued to smoke — unless they had smoked 25 or more cigarettes a day or were already obese at the time they first quit.

"This is good news for light to moderate smokers who are concerned about weight gain. It means that in the long term, quitting smoking will not make that big of an impact on their weight," Veldheer said.

Not so good news was the finding that formerly heavy smokers gained around 23 pounds that could be directly attributed to the loss of their habit, and those obese gained around 16 pounds.

"Although this may seem like a lot of weight, it is important for all smokers to remember that quitting smoking is the single most important thing they can do for their health," said Veldheer. "That being said, for heavy smokers and obese smokers, it may be a good idea to work on quitting smoking while also making other healthy lifestyle changes to control their weight."

While a paunch belly might be more likely for those heavily dependant on a nicotine fix, that likely also means that the benefits of quitting, including a lowered risk of developing certain cancers and heart disease, will be that much greater.

Source: Veldheer S, Yingst J, Zhu J, et al. Ten-year weight gain in smokers who quit, smokers who continued smoking and never smokers in the United States, NHANES 2003–2012. International Journal of Obesity. 2015.