We've never really bought the whole "But it makes me skinny!" line as a justification for smoking. While anyone who's been on both sides knows that it does influence your weight and your appetite, we always assumed that whatever benefits may be reaped by having a lower weight would be negated several times over by the danger of lung cancer and other side effects of a long-term smoking habit.
According to recent research from the Indiana University School of Public Health, however, that may not be entirely true. While there are obvious benefits for your heart and lungs if you quit, the resulting weight gain can be significant enough to increase rates of diabetes. Overall, researchers found that levels of coronary heart disease were lower in post-menopausal women after quitting smoking, with and without diabetes. However, for women who gained 11 pounds or more after quitting, that correlation was weaker.
At this point, the results are still very preliminary and need to be tested more thoroughly — so please, don't take this as a reason not to quit. But, it's worth noting that even after you've tossed your last pack in the trash, it's important to remain conscious of your health in other, and sometimes new, ways. (Psych Central)