Why do people gain weight after quitting smoking?

The damage to the lungs and heart, the smell, the breath are all reasons to quit smoking. It's a hard habit to break, but it's crucial for long-term health. It's a tough road to get it completely out of the system. But why do people gain weight after quitting smoking? While people tend to label it as replacing one habit with another or as an expression of fear, a study provides some much-needed scientific explanations.

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The study, published in the journal Nature, suggests that the gut microbiome plays a role in the connection between smoking cessation and weight gain. Nevertheless, the mechanisms why this happens are not clear.

Scientists developed a series of tests using mice by exposing them to smoke and then observing the fluctuations in their gut bacteria. Initial results showed that mice exposed to cigarette smoke resisted weight gain when they consumed a high-fat diet. When smoking was stopped and the mice continued to eat the same diet, they gained weight.

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Subsequent studies proved the importance of gut bacteria in this situation; Scientists gave the mice antibiotics, which weakened their microbiome, and found that this could have an impact on their weight gain. Finally, the scientists transplanted stool samples from the smoke-exposed mice into normal mice and found that weight fluctuations also occurred in the normal mice.

The researchers then identified the elements in the microbiome responsible for this change, specifically mentioning dimethylglycine (DMG) and acetylglycine (ACG). By increasing and decreasing these elements in mice, they found that weight fluctuations occurred even in mice not exposed to smoke. Healthy mice with DMG supplements gained weight, while healthy mice with ACG supplements lost weight.

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This study also included 96 human participants, all of whom showed similar results to the mice. While this isn't a complete win when it comes to understanding how smoke affects our stomachs, it's an important first step that could help people understand the effects of cigarettes on gut health in the future might even provide some solutions that could encourage people to kick the habit without having to worry about possible side effects.