Cigarette Smoke

Quitting smoking significantly lowers the risk of cancer and cardiovascular disease. In fact, the risk of lung cancer decreases from 18.83 at one to four years after quitting, to 7.73 at five to nine years, to below 5 at 10-19 years, to 2.1 at 20-plus years. The risk of lung cancer for nonsmokers is 1.

Weight gain is a common side effect of quitting, since smoking interferes with pancreatic function and carbohydrate metabolism, leading to a lower body weight in some people. However, not all people experience this lowered body weight from smoking, thus, not all people who quit gain weight. Taste buds and smell are reactivated in nonsmokers, which may lead to increased food intake.