Quitting smoking is useful for a day of health: life becomes longer, the risk of chronic diseases decreases, the quality of life increases. However, weight gain is often associated with quitting tobacco. The scientific evidence for how dangerous these extra pounds is for health is still conflicting.
Differences in how much weight people gain after quitting smoking can be significant. Accordingly, the potential health effects may also differ. However, the effect of the degree of weight gain on human health in real life has been little studied.
In a new study, 17,000 Australians (median age 43) were followed from 2006 to 2014. The information on smoking and body weight of the participants was updated annually according to their words.
On average, participants who quit smoking gained 3.14 kilograms more during the study than those who continued to smoke. Their body mass index also increased more strongly – by about 0.8 units.
Despite the weight gain, the risk of heart disease and type 2 diabetes did not increase in people who quit smoking. At the same time, their risk of dying from any cause was, on average, half that of those who continued to smoke. Scientists found that the risk of death was reduced for all groups of quitters: those who lost, gained and retained their previous body weight.
“The benefits of quitting smoking outweighed the risk when it came to mortality, as the risk of underlying chronic diseases did not increase despite weight gain and an increase in body mass index in those who quit smoking,” the study authors wrote in the findings.
This Australian study contradicts several other scientific studies, including a 2018 study by American scientists, which found that people who quit smoking were more likely to develop diabetes mellitus. However, the risk of death from heart disease and any cause was still lower for them than for those who continued the habit.