Berlin – October 28, 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.