Understanding Why Smokers Gain Weight When they Quit
When smokers quit smoking, one of the first things they notice is weight gain. Even though giving up the habit results in numerous health benefits, some people are unwilling to pack on the extra pounds. In order to get smokers to quit without the fear of weight gain, researchers looked into the possible causes. They explained that ex-smokers gained weight not because they ate more calories, but because of changes in the intestine's bacterial diversity.
For this study, the researchers from the Swiss IBC cohort study worked with Gerhard Rogler of Zurich University Hospital. Together they looked at the genetic material of intestinal bacteria from stool samples. The samples were provided by 20 people over the course of nine weeks. Each participant gave a total of four samples. Of the 20 people, five were non-smokers, five were smokers and ten were ex-smokers who just quit a week after the beginning of the study.
The researchers discovered that the intestinal bacteria diversity between smokers and non-smokers did change over time but only a little. The researchers found that the biggest change in the diversity of the intestinal bacteria was seen in the feces of people who just quit smoking. The people who just quit smoking gained an average of 4.8 pounds even though they did not eat or drink more than they normally did.
This new study confirms previous findings from other studies done on mice models. Now, researchers from the Swiss IBD Cohort study are collecting more medical data of around 2,000 people. The study, "Smoking Cessation Induces Profound Changes in the Composition of the Intestinal Microbiota in Humans," was published in PLOS ONE.