Why Quitting Smoking Makes You Hungry: What Happens in Your Body
Berlin – October 29, 2026 -- Ex-smokers gain an average of 4 to 5 kilograms in the first year after quitting, and the cause is metabolic rather than a lack of willpower.
Two effects disappear when the last cigarette goes out
Nicotine stimulates the sympathetic nervous system, which raises energy use. While smoking, the daily basal metabolic rate is estimated to be about 7 to 15 percent higher, equal to roughly 100 to 250 extra kilocalories per day. After quitting, resting energy use drops back to normal.
Nicotine also acts as an appetite brake. It works on receptors in the hypothalamus that control hunger and satiety, so appetite rises noticeably after quitting.