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Article |Smoking Cessation and Subsequent Weight Change

Smokers wanting to kick the habit needn’t be too worried about gaining a lot of weight after quitting, according to new University of Otago research published online in Nicotine and Tobacco Research.

ASPIRE2025 researcher Lindsay Robertson, who led the study, says some earlier research had suggested that people might gain large amounts of weight after quitting, but many of these studies were not very reliable.

“We hope that our findings will encourage people who are thinking about quitting. They should not be put off by the fear of putting on large amounts of weight. It is important to be aware that a small weight gain is unlikely to offset the health benefits of quitting,” says Miss Robertson.

The researchers also found that being a smoker did not prevent long-term weight gain. All groups in the Dunedin Study tended to put on weight over time, regardless of their smoking status, she says.



People who quit smoking tend to gain more weight over time than those who continue to smoke. Previous research using clinical samples of smokers suggests that quitters typically experience a weight gain of approximately 5 kg in the year following smoking cessation, but these studies may overestimate the extent of weight gain in the general population. The existing population-based research in this area has some methodological limitations.


We assessed a cohort of individuals born in Dunedin, New Zealand, in 1972–1973, at regular intervals from age 15 to 38. We used multiple linear regression analysis to investigate the association between  smoking cessation between 21 and 38 years and subsequent change in body mass index (BMI) and weight, controlling for baseline BMI, socioeconomic status, physical activity, alcohol use, and parity (women).


Smoking status and outcome data were available at baseline and follow-up for N = 914 Study members. People who smoked at age 21 and who had quit by age 38 had a BMI on average 1.5 kg/m2 greater than  those who continued to smoke at age 38. This equated to a weight gain of approximately 5.7 kg in men and 5.1 kg in women above that of continuing smokers. However, the weight gain between age 21 and 38  among quitters was not significantly different to that of never-smokers.


The amount of long-term weight gained after quitting smoking is likely to be lower than previous estimates based on research with clinical samples. On average, quitters do not experience greater weight gain than never-smokers.


Robertson L., McGee R., Hancox R. (2014) Smoking Cessation and Subsequent Weight Change. Nicotine & Tobacco Research doi: 10.1093/ntr/ntt284 First published online: January 24, 2014

For more information please contact:

Lindsay Robertson
University of Otago

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