Smokers who manage to quit gain an average of 4-5kg (9-11lb)– much more weight than the amount usually quoted in health advice leaflets – research has revealed.
While such leaflets often say quitters typically put on 2.9kg in weight as a result, the reality is they have often added an extra 4-5kg after a year.
The 2.9kg figure is an “inaccurate” underestimate and doctors should give patients who want to quit a more realistic picture, says the study.
“Smoking cessation is associated with a mean increase of 4-5kg in bodyweight after 12 months of abstinence, and most weight gain occurs within three months of quitting,” says the research published on the British Medical Journal’s website.
A year after giving up, 16% of people had actually lost weight compared with when they smoked, the team of UK and French medical academics found.
However, 37% had gained up to 5kg, 34% had gained 5kg-10kg and 13% – almost one in seven – were at least 10kg heavier.
About half of quitters gained 1kg-8kg, the researchers found.
Quitters who gave up using nicotine replacement therapy, such as patches, had gained slightly less weight after a year (4.5kg) than those who did so using just willpower (4.7kg) or either the drug Zyban (4.8kg) or its rival Champix (5.3kg), according to the review of 62 previously published studies of weight gain after giving up smoking.
But Dr Paul Aveyard, a GP and professor of behavioural medicine at Birmingham University, who co-wrote the paper, said those differences were not significant.
“It would be wrong to assume that one drug helps ensure less weight gain than another and equally there’s no evidence that either Zyban or Champix causes, prevents or limits weight gain”, he said.
About 20% of adult Britons, 9.6 million people, smoke. Every year, 40% of them (3.8 million) try to quit.
But only 5-6% of those who try, or 2-3% of all smokers – about 192,000 people – succeed.
Weight gain is common because nicotine in cigarettes is an appetite suppressant. A bigger appetite is one of the widest-spread and longest-lasting side effects of giving up.
“The finding of a mean weight gain of 4.7kg in untreated quitters at one year after cessation is substantially higher than the 2.9kg often quoted in smoking cessation advice leaflets,” the study says.
Its findings may deter women in particular from trying to quit because, it suggests, studies show women are prepared to accept gaining no more than 2.3kg as a result of quitting.
“We don’t want smokers to panic as a result of this research and think they are all going to put on huge amounts of weight, as that’s not the case,” said Glyn McIntosh, chief executive of the smoking cessation charity Quit. “It’s different for everybody. Some people don’t put on any weight at all.”
Exercising while trying to give up and afterwards, and eating healthily, can help stop weight gain, she added.
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