14 DAY TRIAL // Contrary to popular opinion, people who quit smoking do not put on weight because they start overeating. On the contrary, their getting a tad plumper is due to the fact that their intestinal flora changes, researchers at the Swiss National Science Foundation say.
By the looks of it, about 13% of those who kick the habit manage to keep their figure. However, the remainder 87% soon find that they are in dire need of a new wardrobe.
Investigations have shown that, shortly after they give up smoking, your average Joe and Jane puts on some 7 kilograms (15.4 pounds).
Oddly enough, this happens regardless of whether or not their daily caloric intake increases.
What's more, researchers claim that even people who start eating less than they did in their smoking days still put on weight.
In a paper published in the journal PLOS ONE, scientists argue that this weight gain is brought about by changes on the former smokers' intestinal flora.
They say that, after studying the make-up of several stool samples collected from twenty volunteers over the course of nine weeks, they found that those who had quit smoking about a week prior to the debut of this study started housing more Proteobacteria and Bacteroidetes in their intestines.
Such changes were not reported in the case of volunteers who either had never smoked, or simply did not quit throughout the duration of this research.
Interestingly enough, these bacterial strains can also be found in larger numbers in the guts of people suffering from obesity, Science Daily explains.
According to the same source, this increase in the number of Proteobacteria and Bacteroidetes inhabiting the former smokers' guts was accompanied by an average weight gain of about 2.2 kilograms (4.8 pounds).
Scientists suspect said bacteria foster an increase in one's body size due to the fact that they boost the body's ability to absorb nutrients from food.