The idea that intermittent fasting can help fight unwanted inflammation isn’t new, but leading research shows that intermittent energy restriction boosts brain function while making positive changes to the gut microbiome.d.
Fasting can rewire the brain, new research suggests
Basic research in China, held in 2023, has since been backed by a promise of follow-up work, including 2024 A project that showed how fasting and protein fasting not only helps with weight loss, but also improves the presence of positive gut bacteria. The theory is that fasting not only burns fat, but also improves your body’s ability to fight cravings, even as it rewires the brain.
“The gut microbiome is thought to communicate with the brain in a complex, two-way manner” explained Dr. Xiaoning Wang from the Institute of Geriatrics of the PLA General Hospitalwho served as a co-author on the 2023 study. “The microbiome produces neurotransmitters and neurotoxins that enter the brain through the nerves and bloodstream. In turn, the brain controls eating behavior, while nutrients from our diet alter the composition of the gut microbiome.”
This is important because some of the changes in eating behavior that occur as a result of intermittent fasting include appetite suppression and greater self-control regarding excessive caloric intake. Of course, with more than a billion people with obesity worldwide, a better understanding of how intermittent fasting can help in the fight against tumors is of great concern.
How intermittent fasting changes the gut microbiome
In the original study, a small sample of participants was put on a 32-day fasting phase, gradually restricting their calorie intake until they reached 25% of their energy needs. After that, the 30-day phase was 500 calories a day for women and 600 calories for men. By the end of the trial, subjects had lost about 7.8% of their original weight and experienced a reduction in body fat and waist measurements. But that was not all. Blood pressure levels improved, as well as cholesterol and liver enzymes. Using magnetic resonance imaging, the scientists also showed that brain regions associated with appetite, emotion and reward were rewired.
“A healthy and balanced gut microbiome is essential for energy homeostasis and maintaining a normal weight,” said co-author Dr. Yongli Lee. “In contrast, an abnormal gut microbiome can alter our eating behavior by affecting a specific brain region associated with addiction.”
The link between brain function and fat loss
Changes in brain activity show that intermittent fasting doesn’t just burn fat when you’re in a calorie deficit. It can also help us better control our decisions about the food choices we make. 2023 follow-up studies and reviews have shown that the presence or absence of certain bacteria in the gut can be directly related to brain function. For example, the presence of Flavonifractor plautii was associated with greater levels of attention, emotional regulation and learning ability.
Since one of the biggest obstacles to fat loss is a matter of willpower, the idea is that intermittent fasting can put us in a better position to make positive choices without the need for medication. “The next question to be answered is the exact mechanism by which the gut microbiome and the brain communicate in obese individuals, including during weight loss,” said Dr. Liming Wang. “Which specific gut microbiome and brain regions are important for successful weight loss and healthy weight maintenance?” Important work continues to determine the best type of fasting, protein and calorie intake to achieve the best results in this exciting area of study.
