Fasting – you hear this tip over and over again. It not only melts fat deposits, but also works against high blood pressure, diabetes and other common diseases. Why fasting can do a lot for one day, how it rejuvenates every cell and how to fast properly, for example when taking medication: you can find out here.
Fasting is not a diet developed by nutritionists that excludes certain nutrients, such as carbohydrates or fat. “Nobody invented fasting and it is firmly anchored in our genes,” explains Eva Lischka, chairwoman of the medical association for therapeutic fasting and nutrition and chief physician at the Buchinger-Wilhemi-Klinik on Lake Constance.
Fasting has ensured survival for thousands of years by the body switching to a different metabolic mode during times of starvation.
What is fasting?
Today, fasting is defined in the guidelines of the ÄGHE as the voluntary renunciation of solid food and luxury foods for a limited time. Classic fasting programs are primarily therapeutic fasting in variations according to Otto Buchinger or periodic fasting, whereby individual days are fasted for up to 16 hours.
The rules for therapeutic fasting:
- A total of at least 2.5 liters of calorie-free liquid per day, such as herbal tea with a little honey, as well
- Vegetable broth
- Fruit juices
- Vegetable juices
250 to 300 kcal per day are useful.
“Promotion of all elimination routes, moderate exercise, such as going for a walk in the fresh air, and relaxation exercises round off the program”, adds Eva Lischka. If you are fasting for the first time, it is best to fast in a group when off work or according to a good fasting book.
Fasting is not starving
Ultimately, fasting must be differentiated from starvation. Only drinking tea and water and avoiding the other components, i.e. not consuming any calories at all, is definitely not recommended.
“Starvation is a forced foregoing of food and therefore triggers much stronger stress reactions in the body than voluntary fasting,” the expert explains the difference.
Take vitamins while fasting?
“Additional vitamins are usually not necessary because there is no digestive work,” says the expert. For patients who take medication, vitamin level monitoring and appropriate supplements may be indicated, for example vitamin B12 when taking acid blockers.
Fasting effect after 24 hours
Anyone who deals with fasting for the first time is happy to try it for a day, of course with the right drinks in the right amount. Even 24-hour fasting has measurable, positive effects. The usual metabolism changes because there is no food.
“The body first uses up the stored carbohydrates, ie glycogen, these reserves last for one to one and a half days,” explains the chief doctor. Autophagy also comes into play. This is a sophisticated recycling system in the body that removes defects from the cells.
Eva Lischka: “You can imagine that cell waste (aged, functionless or incorrectly assembled cell components) is surrounded by a shell. In it, enzymes break up these parts. ”The individual components are returned to the cell and help to rebuild healthy cell components.
The body starts this autophagy program after a break from eating for 14 to 18 hours, which is definitely after a day of fasting. Incidentally, there was a Nobel Prize for work on autophagy in 2016 for the Japanese researcher Yoshinori Ohsumi.
… after two weeks
Periodic fasting such as therapeutic fasting for one to three weeks not only sets these processes in motion over a longer period of time – a corrective for the entire body, comparable and simplified to a “major cleaning”. In addition, the entire metabolism changes.
What this means: If the food break lasts longer, glycogen, i.e. sugar, which is urgently needed by the brain, has been used up. Now the body can produce sugar from certain protein. He succeeds above all from the support protein (connective tissue) in overweight people and to a lesser extent from muscle protein.
However, the sources are limited and not all protein may be used up. Therefore, the organism falls back on fat reserves. “Fat consists of glycerine, which can also be converted into sugar, as well as fatty acids,” explains the expert, explaining the underlying mechanism. The fatty acids are broken down into ketones, with which the brain can operate its energy metabolism – instead of sugar.
“First, the inner belly fat is broken down,” says Eva Lischka. This is particularly beneficial because this fat depot produces, among other things, more than 600 messenger substances that can be linked to metabolic disorders such as diabetes, inflammation and cardiovascular diseases.
… after 40 days
The body’s fat reserves last for many weeks in most people. “A healthy man who weighs 70 kilograms and is 1.70 meters tall can fast for 40 days without any problems, that is scientifically proven,” reports the therapeutic fasting expert. If the man weighed 90 kilograms, he would even have reserves for 100 days. During this time, the whole body is fundamentally cleaned, so to speak.
Dangerous side effects usually do not occur even during this “biblically” long fasting period. To be on the safe side, however, in patients who have been fasting for several weeks in the clinic, sodium and potassium are checked by blood test after three weeks so that no mineral deficiency stresses the organ functions. An EKG is also written to check the heart rhythm.
The fear that muscles (protein) will be broken down through therapeutic fasting is usually unfounded. The organism has, so to speak, a natural brake that protects muscle protein resources. Speaking of muscles. Many fasters report that their physical performance increases and muscles even continue to build. Studies at the beginning of the millennium have already proven this effect.
Fasting has many effects – weight loss is not a priority
With a week of therapeutic fasting, an average of two kilograms can be lost. The expert emphasizes, however, that the waist size is more decisive for health, because it provides information about the risky inner belly fat. A single day of fasting can produce one to two centimeters here. The limit for unhealthy waist circumference is 80 centimeters for women and 94 centimeters for men. It is ideal to lie underneath.
Fasting is anti-aging for the body
Further effects on the organism:
- Blood pressure that is too high drops because table salt is excreted and only supplied in very small quantities (e.g. through vegetable juice). Sodium chloride plays an important role in hypertensive patients. In addition, relaxation and rest, as recommended for therapeutic fasting, also regulate blood pressure.
- Blood sugar and blood lipids (triglycerides) decrease due to the lack of food, which benefits blood vessels
- Liver recovers , gamma GT values have been shown to decrease.
“A very special effect, however, is that new stem cells are formed during fasting ,” reports Eva Lischka. In addition, new mitochondria, i.e. cells’ power centers, are created. This biochemical process is called mitohormesis. When fasting, old mitochondria are discarded and this deficiency triggers mitohormesis.
Therefore, fasting and reducing calories prolong life, which numerous studies have already proven.
Fasting brightens the psyche – but not always the euphoria of fasting
In the beginning, fasting means a certain stress for the body, the sympathetic system is activated because it is about survival. But after two or three days the parasympathetic nerve comes into play. That means mental calm, relaxation, balance. In addition, dopamine and serotonin are now more effective, which makes us happy and slows our appetite. This is also the reason why hunger is usually only a problem on the first day during the fast – but this can be remedied with a lot of drinking and a spoonful of honey.
Last but not least, the body’s own endocannabinoids are strengthened, which also balances and improves mood.
The often cited fasting euphoria is supposed to be triggered by all these factors – but it does not have to be clearly pronounced in every fasting person.
Fasting as a therapy with an amazing effect
So foregoing food means much more for mental and physical health than expected. Fasting is therefore recognized as a therapy or supplement to a treatment for many different diseases. A recent study has only recently shown how well therapeutic fasting works: “Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjectsim” was published in the specialist journal “ Plos One ” .
Diabetes improves permanently – sometimes without medication
Accordingly, diabetes improves significantly during fasting. “Fasting makes receptors important in diabetes sensitive again,” explains the expert. In diabetics, the insulin receptors are often blocked by fatty acids (insulin resistance), and the sugar can no longer get into the cells. The pancreas therefore produces even more insulin, the insulin level rises, and diabetes develops.
“Many diabetics do not need medication during fasting and even less after fasting because the receptors work better again – and because after the cure the patients are more open to a lifestyle change with exercise and a more conscious diet,” explains Eva Lischka.
High blood pressure decreases
It has also been proven that hypertensive sufferers benefit from therapeutic fasting. Fasting affects certain substances called natriuretic peptides. They ensure that water is excreted and fat is burned. “Here researchers were able to show that fasting improves these activities,” explains Eva Lischka. Especially at the beginning of the fast, a lot of water and table salt are excreted, which lowers blood pressure.
Incidentally, this effect has been shown to persist somewhat even after the fast. It also plays a role here that the patients do not weigh as much after the treatment as they did at the beginning. Every kilogram less can lower the blood pressure in overweight hypertensive patients.
With fasting for joint pain and migraines
Diseases that are kept going by silent inflammation, such as rheumatism, arthritis, irritable bowel syndrome, but also migraines, respond well to fasting. “Fasting is anti-inflammatory,” says the expert. Because every meal is foreign contact for the body, it triggers inflammatory reactions (postprandial leukocytosis and start of the Nuclear Factor kappa B ( NF-kB ) inflammation signaling pathway. This in turn can support existing inflammation. If the foreign contact with food disappears, the body is spared and additionally relieved of digestive work.
The question remains whether therapeutic fasting could also reduce the risk of cancer or improve the prognosis in the event of illness. “The studies are still ongoing here,” says the expert, curbing expectations that are too high. However, it is now considered certain that it is beneficial not to feed the tumor with sugar during chemo. Then the tumor is more sensitive to chemotherapy and the patient can also tolerate the treatment better.
Fasting works – and has hardly any yo-yo effects
This therapeutic effect of fasting lasts for months for many patients. This also applies to weight maintenance. On the subject of the yo-yo effect, the nutritionist Françoise Wilhelmi de Toledo carried out a study at the clinic with 400 patients who performed around ten fasts over a period of ten years. The result:
- a third had held the weight
- a third had lost even more
- a third had increased slightly
So two thirds were quite successful. “At our clinic, we have found that these effects persist for around six months in our severely overweight patients, then it makes sense to fast again for at least ten days – this includes days off and slowly returning to normal food,” reports the Chief physician.
For some people, however, it has also proven useful to fast one day a week afterwards or to do 16: 8 intermittent fasting, i.e. either without breakfast or without dinner. In this way obesity and metabolic changes can be prevented and obesity can be prevented.
Who is allowed to fast and who is not, or only with the doctor
In principle, almost anyone can practice fasting as a prevention and therapy, but there are exceptions. The following are contraindications for fasting:
- Breastfeeding and pregnancy
- eating disorder
- mental illnesses such as psychosis
- (advanced liver or kidney failure)
Women who use birth control pills should use additional contraception during and after fasting, for example with condoms, depending on the type of pill. The effect of the pill is not certain during fasting because the absorption, as with diarrhea, may not be complete
“Anyone who takes medication is only allowed to fast under medical supervision,” adds Eva Lischka. There are trained fasting doctors and fasting leaders at:
- Medical Association Fasting and Diet
- German fasting academy
- Association for independent health advice
Problem toxins in adipose tissue
So almost everyone can fast and everyone can benefit from it. However, there may be a downside to fasting. Many toxins from our environment are stored in adipose tissue. When you lose weight, they are dissolved and get into the blood and could put strain on the liver and kidneys. “It’s true, studies show that toxins from adipose tissue get into the blood during fasting, but you don’t know whether this will finally dispose of them and rid the body of these substances,” reports Eva Lischka. This has not been adequately investigated.
On the other hand, we know for sure that losing weight frees you from dangerous visceral fat. Three quarters of men and more than half of women have too much of it. This belly fat is so risky because it sets off silent inflammation. These silent inflammations are significantly involved in the main causes of death, heart attacks, strokes and, in some cases, cancer. Without belly fat, the risk of these causes of death also decreases. This is another reason why fasting can be life-extending.
“As long as studies have not proven otherwise, we should therefore rely on our experience,” emphasizes the chief doctor. She treats many patients who have been fasting for decades and have been able to improve their chronic illnesses, and who often appear biologically much younger. If the toxin exposure from fasting were really pronounced, it would definitely have been noticed.
And what must not be forgotten: “Eating and drinking unhealthily puts a lot more strain on the liver and kidneys than fasting.” Every ingestion of food is contact with foreign substances and triggers a slight inflammatory reaction, not to mention the harmful substances and toxins in our diet – Pesticides, pollutants, microplastics and more.
Fasting is undisputedly a tried and tested and simple method not only to get rid of dangerous belly fat, but also to regenerate and, so to speak, rejuvenate the organism as a whole. It is not only recommended for healthy people, but can also complement or perhaps even replace a therapy for many diseases, such as type 2 diabetes, but in any case relieve and prevent the common diseases of obesity, high blood pressure, arteriosclerosis and joint inflammation.