How Fasting Works to Reset the Digestive System. Intermittent fasting provides periods of rest for the digestive system, reducing the constant workload of digesting and absorbing nutrients. This rest period can reduce inflammation in the gut and improve issues such as bloating and irregular bowel movements.
There are trillions of microorganisms living in your intestines, helping to break down your food and make nutrients like B vitamins and vitamin K. 12 Fasting can be one of the many ways to improve overall gut health by helping these microorganisms thrive.
Fasting can be a cause of increased stomach acid production due to an empty stomach and not getting food. The function of food is to neutralize an acidic stomach condition due to excessive stomach acid production.
A 48-hour fast can serve as a reset for the body, allowing it to take a break from digestion to focus on other tasks. This break may allow it to focus energy elsewhere, such as on repairing the body.
After four weeks of consistent fasting, research shows that you should have measurable improvements in blood-glucose levels, insulin levels, insulin sensitivity, and blood pressure to accompany favorable changes in your body weight (assuming you had some excess weight to lose).
Eat plenty of fiber-rich foods.
When you think about your diet, consider the number of plant-based foods, grains, legumes and beans you're eating. Foods high in fiber, especially prebiotic fiber, balance your gut increasing good bacteria and starving bad bacteria.
The researchers also found that every-other-day-fasting – where no food was consumed on alternate days – changed the metabolism of fatty acids in the liver, knowledge that could be applied to improvements in glucose tolerance and the regulation of diabetes.
If you're eating a produce-rich, high-fiber diet, you will likely have healthy, regular bowel movements. Most people who try intermittent fasting don't see much of a change in their poop, Julie Upton, RD, Health's registered dietician and writer, told Health. However, some people say they poop less frequently.
Many medical experts agree that a one-day fast can feel great. But extending beyond three days can begin to cause harm, especially if you have other medical conditions, such as diabetes or heart disease. “A fast longer than a day or two can deplete vitamins, minerals and electrolytes,” Dr. Hopkins says.
These results indicate that intermittent fasting may have modulatory effects on the immune system and reduce intestinal inflammation [14].
Another study from the Journal of Clinical Investigation [Reference 2] found that fasting periods can trigger cellular autophagy, contributing to metabolic rejuvenation. These findings underscore the potential benefits of extended fasting in achieving metabolic balance and health.
When the digestive tract is put temporarily at rest during periodic fasting, it remodels its structure leading to a reversible atrophy as shown for rat intestinal villi(10). In addition, changes in gut motility, total intestinal mass(11) and microbiota composition have been described in the gut of fasting animals(12).
Essentially, fasting cleanses our body of toxins and forces cells into processes that are not usually stimulated when a steady stream of fuel from food is always present. When we fast, the body does not have its usual access to glucose, forcing the cells to resort to other means and materials to produce energy.
The findings also suggest that regular fasting over a long period could help reduce chronic inflammation associated with certain diseases, they said. The findings may also help explain some of the beneficial effects of non-steroidal anti-inflammatory drugs such as aspirin, they said.
Effects in humans
In a pilot study in 13 patients with chronic kidney disease, cycles of the fasting-mimicking diet were kidney-protective, including reducing proteinuria and improving endothelial function compared with patients who did not receive dietary intervention.
A 7 day gut reset may involve eliminating processed foods, sugar, and other potential food triggers, and consuming a diet that is rich in whole foods, fiber, probiotics, and prebiotics.
As part of a balanced diet, eggs contribute to a healthy digestive tract and can be helpful during acute digestive problems. In addition to being packed with nutrients, eggs are usually easy to digest compared to some other high-protein foods, such as meat and legumes.
Expect your results to slow down after a year. During my first year of intermittent fasting, I lost a lot of weight, shed a good chunk of fat and leaned into the best shape of my life. But after my first year, my weight and fat loss reduced significantly, and the results slowed down over the years.
You may need a longer or shorter eating window, or you may want to try out a new protocol entirely. Decrease (or increase) your calorie intake within your fasting window. Aim for 7–9 hours of sleep. Cut back on processed foods.
With intermittent fasting, breakfast is not only optional, it's discouraged. The most common method is a 16-hour overnight fast, followed by an 8-hour eating window. Yet, nutrition professionals have long suggested that breakfast is critical.