Fasting would have positive effects on weight loss, aging or even certain diseases. However, it is not without risks. What happens when you fast and how do you do it appropriately? Why Doctor takes stock.
A fast consists of stopping food, for a day or several weeks, and living on the body’s reserves. Originally, it was a religious ritual, associated with prayer and almsgiving. Muslims practice it during Ramadan, Jews during Yom Kippur and Catholics during Lent. During antiquity, philosophers like Socrates and Plato also chose to fast to improve their intellectual performance. Then, over the centuries, this practice began to be associated with hunger strikes carried out by peaceful demonstrators, the best known of course being Gandhi. But in recent years and the detox fashion, fasting has come back to the fore for its possible therapeutic virtues. More and more individuals practice it intermittently to “cleanse their body” and some doctors even recommend it to their cancer patients. What happens to our body when we fast? What are the advantages of such a method and what side effects can occur? Why Doctor takes stock.
What happens to our body when we stop eating?
When you stop eating, a metabolic process quickly takes place to mobilize the body’s fat stores. The brain, which needs glucose, uses fat stores from adipose tissue. It then converts the triglycerides into glycerol which in turn becomes glucose. If the fast lasts too long, the body will begin to draw on the muscles to produce it. In doing so, it will use proteins which it will transform into amino acids, then into glucose. This is the gluconeogenesis phase (synthesis of glucose from non-carbohydrate precursors).
What are the benefits of fasting for the body?
First of all, fasting cleanses the body. For hundreds of thousands of years, famines followed good times for humans and the body adapted to these changes. “When you eat too much, you store the excess in anticipation of these periods of scarcity and famine, explains Thierry de Lestrade, author of the documentary Fasting, a new therapy ? at France Inter. Today, in our industrialized societies, we live with a full fridge. We no longer need to store – but we still store fat. You have to destock, it’s a physiological need: fasting corresponds to this need.
According to many experts, due to its action of great cleaning of the intestine, fasting would allow digestive enzymes to better divide food into molecules. Ultimately, intermittent fasting (alternating between periods of eating and prolonged periods of not eating) would therefore have a beneficial effect on allergies.
Intermittent fasting is also known to lower chronic inflammatory diseases and cholesterol and to help with weight loss. Indeed, according to a study published this summer in the journal Cell Metabolism, people who alternated between 36 hours of zero-calorie intake and twelve hours of unlimited eating for a week achieved an average calorie restriction of about 35% and lost an average of 3.5 km. “Previous studies have suggested that low-calorie diets can lead to malnutrition and decreased immune function, whereas after 6 months of fasting every other day, immune function in participants appeared to be stable,” the researchers noted. . Additionally, all 60 study participants had reduced levels of slCAM-1, a marker linked to age-associated disease and inflammation, and had lower cholesterol levels than before the onset of the test. ‘experience.
Fasting would also have positive effects on aging, the risk of cancer and cardiovascular disease. In 2015, researchers at the University of North Carolina subjected their study participants to five days of half-fasting per month. Three months later, the majority of them had significantly reduced biomarkers linked to cancers, aging and cardiovascular disease, regardless of how they ate the rest of the time. This could be explained because fasting reduces the production of a hormone at the base of the development of cancer. But in general, intermittent fasting would be most effective in slowing down aging. “Strict fasting is very difficult for some people to follow, and sometimes it can be dangerous. This is why we have developed this diet which achieves the same performance as fasting”, explained the researcher behind the study. “I have personally tested both ways, and the latter is much simpler, and above all, safer,” he concluded.
Prepare well for your fast
Of course, fasting is not something to be done lightly. If you plan to fast for several consecutive days, prepare your body beforehand so as not to traumatize it. Start by banning foods that are difficult to digest, such as red meat for example. Forget sodas, alcoholic beverages, coffee, salt and sugary desserts that make you thirsty and lower blood sugar levels after a few hours. Choose well-cooked food and drink enough water to stay hydrated on the first day of fasting.
Once the big day has arrived, you can perform an intestinal purge (discuss this with your doctor beforehand). In pharmacies, you can buy a sachet of magnesium chloride or sodium sulphate to empty your digestive system. This will allow you to enter the fasting period more quickly.
What possible side effects and how to avoid them?
A fast of only a few days does not represent a big danger because it is a normal physiological process. However, it is contraindicated for pregnant women, people with kidney failure or a BMI of less than 18. In individuals with a stomach ulcer, type 1 diabetes or cancer, very strict medical monitoring is recommended.
But even if you are in good health, you are not immune to some small inconveniences, especially the first few days. At the beginning, you may feel a cold sensation. Indeed, who says fasting says absence of heat released by the digestive work and reduced production of thyroid hormones. Do not hesitate to cover yourself more and drink hot water in the form of herbal teas or infusions.
Moreover, fasting without compensating for the loss of mineral salts can lead to hypotension. This can lead to dizziness or even falls. What’s more, a potassium deficiency can pose a risk to the heart. To protect yourself, choose mineral salts. Thanks to their alkalizing properties, these will fight against acidosis (increase in blood pH) and thus limit the effects of the state induced by low carbohydrate diets such as nausea, migraines or even bad breath.
These inconveniences “are linked to significant metabolic acidosis (lower pH of blood plasma which becomes more acidic): indeed, from the 36th hour of fasting, ketone bodies are produced by the body from fat reserves. It is a compensation process that is triggered when the body can no longer draw on its glucose resources as a source of energy”, explains Dr. Coudron, specialist in fasting, to the Doctissimo website.
Finally, you can also supplement yourself with poly-vitamins and main trace elements to boost your body during fasting.
How long should you fast?
If intermittent fasting seems to have many positive effects, three consecutive days would allow the body to make a new skin and a whole week to deep cleanse. If you want to go even further, it is strongly recommended that you do so under the supervision of an experienced doctor.
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