Smoking, statins and fish oils

Smoking and weight gain

BMJ 2012;345:e4439

On average, people who quit smoking gain almost 5 kg in weight during the next year, according to a meta-analysis of 62 studies. However, almost one-in-six lose weight after smoking cessation.

People who quit smoking without additional treatment (eg nicotine replacement therapy) gained, on average, 1.12 kg during the month after quitting, 2.85 kg after three months, 4.23 kg after six months and 4.67 kg after a year.

However, the changes in weight varied widely: 16 per cent of people lost weight after quitting, 37 per cent gained less than 5kg and 13 per cent gained more than 10kg. After a year, people who used nicotine replacement therapy gained, on average, 4.86 kg compared to 4.08kg and 4.17kg with bupropion (300 mg daily) and varenicline (2 mg a day) respectively.