New research shows those who are more nicotine dependent are more likely to gain weight. Exercise and diet are an important part of kicking the habit.

Weight gain is a common concern for people who are thinking about quitting smoking. And new research shows that a person’s dependency on nicotine determines how much weight he or she is likely to gain after quitting.

Researchers at the Kyoto Medical Center in Japan examined the factors that lead to weight gain in people who stop smoking. They found that the more heavily addicted a person is to nicotine, the more weight he or she is likely to gain.

They studied 186 patients at a smoking cessation clinic with an average age of about 60 who smoked more than one pack a day, on average. In the three months after quitting, those with a greater dependence on nicotine experienced the most weight gain—about 2.5 pounds.

Since most of the study participants were using some form of nicotine replacement, such as a patch or varenicline (Chantix), the weight gain was less significant than it would have been had they gone cold turkey, like two of the participants in the study.

“Body weight gain itself is considered a factor that hinders the desire to quit smoking. From these considerations, for effective smoking-cessation treatment, at the initial outpatient examination for smoking cessation, one must determine the patients expected to gain weight after ceasing smoking, and perform weight control accordingly,” researchers concluded. Their study published this week in the journal PLOS One.

Weight gain after quitting smoking is attributed to numerous factors, including increased appetite, a decreased rate of metabolism, decreased physical activity, and increased lipoprotein lipase activity, which affects fat transportation in the body.

The Kyoto team dug through prior research and found that, on average, men only gain about six pounds after quitting smoking, while women only gain about eight pounds. About 10 percent of quitters of both genders gain 28 pounds or more.

However, post-quitting weight gain typically only lasts for about three years, while quitting smoking remains a good long-term health decision.

While tobacco use affects a person’s weight by increasing their rate of metabolism, its negative health impacts are considerably worse than those of a few extra pounds. Besides the array of cancers linked to tobacco usage, smokers are also more likely to develop blindness or degenerative disc disease, have a limb amputated, or suffer from impotence.

Adding exercise and a healthy diet to your post-smoking routine can help mitigate weight gain, which is exactly what the Kyoto researchers recommend for people with severe nicotine addiction.

Not only can exercise and diet prevent weight gain, it will also help lower the risk of heart problems and glucose intolerance (a pre-diabetic condition) associated with excess weight gain.

So, if you’re concerned about the weight gain that usually follows quitting smoking, it’s best to quit now before you become more dependent and gain more weight as a result.