Given that more and more people are now accepting fasting therapy as the first choice for weight loss, with outstanding results and an easy process. So once again, a question and a concern for many people: what kind of impact does fasting therapy, or the various methods of weight loss with calorie restriction at its core, have on the digestive system? Will it starve the stomach? This question is clouded for many people. Therefore, although I am not completely thorough, I feel the need to do my best to fasting therapy as an example, here to make a proper explanation. The digestive system is one of the eight major systems of the human body. It includes the digestive tract and the digestive glands. The digestive tract is divided into upper and lower, no nonsense, basically “stomach up and intestines down”. The digestive glands include the three major salivary glands (parotid, submandibular, and sublingual), the liver, and the pancreas. So when we talk about the effects of fasting therapy (FT) on the digestive system, we will divide it into two parts, the first is the digestive tract and the second is the digestive glands. First, let’s talk about the digestive glands. Let’s start with the liver. In fact, one of the effects of fasting on the liver has already been explained in the article “Staying up late for health” (reply to “Staying up late for health” in the public interface to see how to protect the skin after staying up late). That is to scavenge free radicals and anti-oxidative stress. The other effect of fasting on the liver is to reduce fatty liver, mainly non-alcoholic fatty liver. In my own animal experiments, fasting in rats on a chronic high-fat diet significantly improved fat infiltration in the liver, resulting in a significant reduction in the severity of fatty liver in rats on a high-fat diet, approaching that of rats on a normal diet. Fasting also improved coagulation function (one of the main functions of the liver). In our long-term clinical practice, we have observed that women with previously pushed-back menstruation and low menstrual flow gradually have earlier periods and more frequent periods after fasting. In patients with polycystic ovary syndrome (PCOS), after a course of fasting, distant relatives who used to come once every six months and a year became familiar with each other and visited every month. Of course, we forbid fasting during or before menstruation for those who originally have heavy periods. At the same time, during fasting, a large number of biochemical reactions related to energy metabolism take place in the liver. Therefore, while the gastrointestinal tract is resting, the liver is working under a heavy load. As a research group full of humanism and loving care, we will protect and comfort appropriately. We don’t want the horse to run and we don’t want the horse to eat grass, we are not a “light driver”. Moving on to the salivary glands. During fasting, saliva production decreases, while bacteria in the mouth multiply and degrade. At this time, problems can occur, including: thickening of the tongue, bad breath (bacterial protein degradation), etc.. This is a normal physiological reaction, and increased oral cleaning or the use of breath fresheners can be used. Also, fasting has a significant effect on reducing the inflammatory response throughout the body, thus facilitating the improvement of mouth ulcers. The effect of fasting on the digestive tract is mainly reflected in the mechanical movement and bacterial regulation. First of all, during fasting, the entire upper and lower digestive tract will be in a light “hibernation” state, “let your gastrointestinal tract wash and sleep”. Moderate rest is conducive to the two-way benign regulation of the mechanical movement of the gastrointestinal tract. Especially for patients with irritable bowel syndrome, this benign regulation of mechanical movement can reduce their pain. In fact, irritable bowel syndrome is divided into diarrheal, constipated and mixed types. The regulation of mechanical movements can improve diarrheal IBS, while the regulation of intestinal flora disorders can help improve constipated IBS, and as for the mixed type, it works both ways! In addition, the possible mechanisms of irritable bowel therapy include: reduced secretion of intestinal fluid and reduced stimulation of intestinal nerves leading to slower intestinal motility. As for the adjustment of enteropancreatic axis function by fasting, it belongs to the topic of endocrine, which will be mentioned later. By the way, Chinese people like to say that “the brain is full of intestinal fat”. The effect of fasting therapy or caloric restriction on the nervous system is currently thought to be beneficial to the prevention and treatment of neurodegenerative pathologies, including Alzheimer’s disease and Parkinson’s disease, etc. I’ll give you another round when I’ve clarified my thinking. Secondly, what has to be said about the regulation of intestinal flora: regardless of the presence of constipation, the type and number of intestinal flora in obese people are significantly different from those with normal or lean body size. The findings of Jeroen Raes of the VIB Institute of KU Leuven, published in Nature, who studied nearly 300 Danes, concluded that the abundance of intestinal flora correlates with obesity susceptibility. After Archimedes published his great “prying earth” theory, the professor’s study basically says: Give me a piece of poop and I’ll know if you’re fat or thin. The happy result, of course, was the publication in the same issue of Nature of a study by the French National Institute of Health and Medical Research that concluded that a six-week low-fat diet could improve the growth of intestinal flora to some extent, both in terms of overall numbers and diversity. Once again, the effects of fasting therapy on the stomach include mechanical movement and acid secretion. First, fasting causes a person’s gastric cavity to shrink slightly and slows down the mechanical peristalsis of the stomach, making a person prone to a feeling of fullness at the end of the fast. Second, in terms of gastric acid secretion, fasting is harder to affect the secretion of gastric acid in the first phase, but it can inhibit the subsequent overproduction of gastric acid. In layman’s terms, this means that 10 parts of gastric acid are secreted during a normal diet, but only about 1 part is secreted during a fast. Therefore, if you are worried about the damage to your stomach caused by excessive acid secretion during fasting, you can basically rest assured. Finally, it is important to mention the side effects of the above effects. The decrease in mechanical peristalsis and secretion of gastric acid and intestinal fluids during fasting may lead to slower emptying of the gastrointestinal tract, resulting in bloating, easy satiety, and even constipation. Therefore, my personal advice is: 1, during the fasting period and after the resumption of diet, can be combined with the “abdominal kneading” in the Tui Na rubbing method of Chinese medicine. 2, during the fasting period, appropriate with the use of low-calorie meal replacement package, can be appropriate to stimulate gastrointestinal motility at the same time, but do not worry about excessive calories affect the weight loss effect. 3, after resuming the diet, the appropriate use of traditional Chinese medicine treatment, can also help the body conditioning at the same time, the gastrointestinal function has a very good regulatory effect.