“After I had given a birth to a second child I decided: I need to lose weight. I read a lot of different literature and decided to focus on the popular method of interval fasting for weight loss. The result was that I lost 3 kg in 5 days. But on the sixth day gastritis escalated, and I had to finish the experiments.”
– Irina, 36, from messages on the thematic forum
Day or even a few days long fasting is a kind of challenge, and a lot of people accept this one. Someone resorts to such an experiment because of the desire to quickly solve the problem of excess weight, someone – to test their willpower. Few people resort to starvation for medicinal purposes, assessing all the risks, consulting with a doctor and making sure that it will not pose a danger to the body.
Proponents of therapeutic fasting claim that it helps to control weight, feel levity, improve well-being, look better, and feel their body and its possibilities in a new way. 
But why doesn’t it work with everyone? Is it possible to lose weight by fasting?
In this article, we will consider all the pros and cons of the idea of fasting for weight loss.
Fasting means the existence of an organism without incoming food from the outside or in the conditions of its extreme deficit. There are partial, incomplete, complete and absolute fasting. The significance of each type and a summary of their effects on the body are presented in the table. 
|Type||Reason||How does it affect the body?|
|Partial (quality)||Eating poor quality foods low in nutrients and vitamins.||Prevents maintaining active life, causes disease, and reduces life expectancy.|
|Incomplete (quantitative)||Eating food with all the nutrients the body needs, but with shortage in calories.||Prevents maintaining active life, causes disease, and reduces life expectancy.|
|Full||Complete lack of a minimum amount of food needed to maintain life. It can take place without restriction or with a limit on the amount of water consumed.||Depending on the duration, condition of the body, environmental factors, and control capabilities, it can have both therapeutic and the opposite effect — up to the death.|
|Absolute (deficit)||Complete lack of food and water.||Danger for health and life.|
Two groups of causes, external and internal, can push for fasting.
Intentional fasting is used for medicinal purposes. Such fasting is possible only under the supervision of a doctor with a preliminary examination. There are many methods of therapeutic fasting, let’s list some of them:
1. Standard full (water) fasting.
Excluding any food intake without limiting water consumption. It is accompanied by daily cleaning enemas and water procedures. Depending on the experience and goals of the starving person, it can last from one to forty days.
2. Dry fasting
Complete refuse of food and water. Enemas and water procedures are excluded. The duration is no more than 3-4 days.
3. Combined fasting
The first 3-4 days – dry fasting, then – standard one. The method reduces the overall duration of fasting. 
4. Fractional fasting by G.A. Voytovich
Several cycles of full or combined fasting following each other (usually three). Each of them lasts from 17 to 20 days, with a recovering diet between them for the same period. 
5. Fasting by P.Bragg
You can drink any amount of water. The fasting takes place in the following mode: one-day fasting once a week, weekly — once a quarter, and three weeks — once a year. Excludes the use of enemas both at the start of the fasting and during the process. 
6. Interval fasting
A food scheme when eating is allowed only at a certain time. The most popular scheme is 8/16. This means that a person can eat for 8 hours, and fast for the remaining 16 hours.
As a rule, the duration of medical fasting does not exceed 21 days, since after that time the risk to the health of the starving person increases dramatically. 
“In search of a solution to losing weight after childbirth, I came across a site about therapeutic fasting. Then I saw a slimmed-down neighbor. When I asked how she managed it, I also heard about therapeutic fasting. Moreover, this happened with a difference of three days. I thought it was fate, it is time to close the question of whether it is possible to lose weight by fasting. So, I’ve made up my mind.
I lost 9 kg in nine days. But for a month of normal nutrition, they came back to me with the additional five. I left the diet according to the rules, without eating rolls and pies, only a healthy diet. My stomach began to hurt, the menstrual cycle was lost, my nails began to break, and hair began to fall out. I didn’t get any therapeutic effect.”
– From anonymous messages on the thematic forum
In official medicine, there is such a thing as a calorie restriction diet (CRD). It means fasting under the supervision of a doctor and is a method of effective treatment of many diseases. With a small number of contraindications, fasting helps to normalize metabolic processes, improves circulation, normalizes the immune system, helps prevent viral infections, etc. The therapeutic effect is because when fasting, protective functions and natural processes of the body recovery are activated.
Sometimes these processes are triggered from within: a person loses appetite during illness and severe stress. In the case of therapeutic fasting, processes are triggered from the outside, which in itself can be stressful for the body. Therefore, you should carefully and gradually accept the idea of fasting, and also gradually cease it. Therapeutic fasting is carried out according to a certain method in in-patient mode and includes not only fasting itself, but also many accompanying procedures.
The list of diseases treated by CRD is given in the table below. 
|Group of diseases||Diseases in which CRD can be used|
|Cardiovascular disease||Hypertensive and mixed type neurocirculatory dystonia, hypertension in overweight individuals, atherosclerosis|
|Diseases of the genitourinary system; and||Prostate adenoma|
|Diseases of the musculoskeletal system||Osteochondrosis of the spine, rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis|
|Respiratory diseases||Bronchial asthma, sarcoidosis of the lungs stage I – II|
|Digestive system diseases||Functional diseases of the digestive system (functional dyspepsia, biliary dyskinesia, intestines), chronic pancreatitis, chronic cholecystitis|
|Skin diseases||Eczema, psoriasis, neurodermatitis|
|Allergic diseases||Food and drug allergies, Quincke edema, urticarial fever|
|Eye diseases||Glaucoma, cataracts, conjunctivitis, keratitis|
|Mental illness||Neurosis, depression, sluggish schizophrenia|
|Metabolic diseases||Alimentary-constitutional and hypothalamic obesity|
Please note that the data in the table are for reference only and cannot be the basis for making a decision to start fasting.
When fasting, internal metabolic processes are rebuilt — the body uses its energy reserves, which contributes to the increased control against cellulite and excess weight.
Starvation has a beneficial effect on the appearance of the skin. Since the condition of the skin is directly related to the work of the intestines, when it is cleaned, inflammation and rashes on the skin are reduced.
Cleaning the body starts at the cellular and molecular levels, which contributes to the rejuvenation of cells and tissues of the body. Researchers have found that fasting can assist in the fight against cancer cells. 
This is a serious method, that is used in several stages and does not tolerate neglect to any of them. Even one day of incorrect fasting can cause serious harm to the body. Therapeutic fasting should be prescribed by a qualified doctor and carried out in specialized wards of the hospital or sanatoriums. It is worth noting that the body of each person is different, and even with compliance with all the doctor’s recommendations, complications may arise, and the general condition of the body may worsen.
As mentioned above, there are many methods of therapeutic fasting, differing in variety and timing. Despite some differences, in the practice of any method of fasting, general principles are distinguished:
Before fasting for 24-36 hours, to prepare the body for fasting it is necessary to observe a moderate gentle diet of dairy products and plant food, vegetables and fruits.
If you didn’t undergo any preparation of your body, it is better to start the practice of the refusal of food with short-term water fasting.
It is recommended to cleanse the intestines with enemas. The stomach shall be cleaned in case of heartburn and belching through the artificially caused vomiting after taking half a liter of water.
From time to time it is necessary to drink pure water (if the selected method is not dry fasting). The total volume of water drunk per day is at least 2 liters.
It is recommended to take a shower twice a day, regularly remove plaque from the tongue using a soft brush.
It is recommended to walk outdoors more often, to wear clothes made of natural fabrics. It is useful to take sunbaths, since the sunlight promotes calcium metabolism, plays an important role in the absorption of phosphorus and maintenance of physical endurance.
During fasting, hypothermia should be avoided. In a cold environment, the body spends additional energy to maintain normal body temperature. This can lead to a deterioration in overall well-being. In the cold season, it is not necessary to practice long-term fasting.
Be sure to observe the correct way out of fasting, gradually increasing the number and variety of products. The preference should be given to plant food and juices. The duration of recovery from fasting should correspond to the number of days of abstinence.
In the process of fasting, there are three consecutive stages: food agitation, true hunger, and exhaustion. Consider the processes that occur in the body at each stage. 
The stomach is emptied, the nutrients in the intestines dissolve. The concentration of nutrients in the blood is reduced. “Hungry” blood sends a signal to change its composition in the center of hunger, located in the brain. The center of hunger becomes agitated and transmits the subsequent signal to the frontal cortex, responsible for nutrition. Gradually, agitation covers other parts of the brain, dominating other requests. A person feels a strong need for food, which he overcomes by willpower and certain techniques (distraction by vigorous activity, cleaning procedures, drinking water). Depending on the state of the organism and individual constitution, the stage of food agitation lasts from 1 to 4 days.
After the agitation period, the processes of the central nervous system slow down. Overcoming the onslaught of hungry signals, the cerebral cortex from the excited state goes into an inhibited one. The feeling of hunger becomes distant or completely disappears. Physiological mechanisms of consumption of energy forces from their tissues are launched: fat reserves are burned, painfully altered tissues are broken down.
After 8-10 days of fasting, the body’s metabolism goes into the economy mode: body temperature and pressure decrease, all processes slow down. It is somewhat reminiscent of the processes taking place in the organisms of animals when they fall into hibernation.
By the end of the true hunger stage, the body uses all the back-up tissue, and the brain regains a state of agitation, which is manifested by a feeling of wild hunger. At this stage, the body can lose up to 25% of its weight in up to 40-50 days, depending on the constitution and general condition.
If a person ignores the body’s signals about the need to get out of the state of hunger and continues it, the”recycling” of vital tissues and organs takes place. This leads to irreversible pathological changes in the body and death from exhaustion. Weight loss reaches 40-45%.
It follows from the above that only the first and partly the second stage of fasting are suitable for therapeutic fasting. Starvation for 21-25 days leads to loss of 12-15 % weight. These indicators are far from a critical trait on average. However, they can also pose a threat to human health and life.
“I began to fast for 16 hours a day. At first, it was difficult: I was dumb at work, I did not have enough strength for training, and I was constantly dizzy. But after two weeks everything was normal. To achieve the result faster, I gradually reduced the time I could eat, and reached 22 hours of hunger per day. Permanent things helped me not to run wild: checking school notebooks, taking a walk with my child, cleaning the apartment, and cooking.
I stayed on periodic fasting from July to mid-September. During this time, I managed to lose 6 kilograms that did not return. I also began to get sick less and solved the problem with hormones: before, the therapist could not feel for the thyroid gland, but now it is even visible. I go to the endocrinologist once a month and take tests. The doctor didn’t like my diet at first, but after looking at my tests, he said I could go on. Just in case, the endocrinologist advised me to drink vitamins. I don’t plan to stop. I live apart from my parents, so they don’t know what I’m eating. At home, my husband is okay with it. Only my colleagues wonder how is it possible not to go to the dining room?”
– Svetlana, 24, from the materials of the poster Afisha. Daily website 
Disputes in the medical community about the dangers and benefits of fasting are ongoing. The studies are regularly conducted proving and refuting the therapeutic effect of hunger and its positive effect in the fight against excess weight. According to statistics, 19% of those who lose weight on diets can keep the weight obtained, 34% get fatter after dietary restrictions, and 47% are not affected by diets in any way. But at the same time, the number of people willing to lose weight due to fasting does not decrease. 
In 2018, the Massachusetts Institute of Technology scientists proved that fasting for 24 hours accelerates metabolism and increases weight loss. According to them, this method turns the “metabolic switch” by causing faster burning of calories and excess fat. As a result of daily fasting, the regeneration of bowel stem cells is enhanced. These cells are responsible for updating the bowel epithelium. The more young cells, the more intensive the organ itself works, by digesting food and burning calories faster. The authors of the study argue that short-term fasting rejuvenates not only the intestines but the entire body in case of regular “nutritional strikes”.
If you want to lose weight and never return to the previous kilograms, 16-hour (or daily – taking into account 8-hour sleep) fasting for losing weight once every 2 weeks or a month can be effective.
The list of contraindications for therapeutic fasting is quite large. Please read it very carefully:
Keep in mind that your lack of a confirmed diagnosis, symptoms or conditions listed on this list is not a reason to make a self-decision about fasting. Fasting can be started only after consultation with a doctor.
When fasting for more than sixteen hours, manifestations of asthenic syndrome are possible: a feeling of physical weakness and superficial sleep. These side effects with their weak severity can be eliminated with the help of auto-training and meditation.
On 3rd and 4th days, with a sharp change in body position from horizontal to vertical (more often – after waking up, in the morning), dizziness may occur with darkening in the eyes. The occurrence of heartburn, belching, slight nausea, and a feeling of discomfort in the stomach are also possible. Sometimes convulsions can occur in the hands, feet, calves, and neck (more often in the morning and night hours). 
In specialized clinics, in order to mitigate these side effects, pharmacotherapy is used. That is why it is necessary to fast under supervision.
“I don’t advise you to fast. My friend and I decided to fast, too. We read the scheme somewhere: drinking only water during a day, and eating an apple and a small snack for breakfast. We both barely walked, propped up each other. It all failed: in a week, my friend began to faint. Of course, we both became nervous, quick-tempered, and tearful … Then I got used to food for a very long time and recovered. Now I understand and think, any doctor will say that it is harmful to the body. I read that people used to be treated with fasting for all diseases. Only this ended in death. “
– Anna, 23, from messages on the thematic forum
It is not surprising the fact that the experiments of Anna and her friend on their bodies were unsuccessful, it is rather natural. Here there was a wrong approach: none of the girls consulted with the doctor, and began to fast “for company.”
Fasting, even under the supervision of specialists, very rarely passes without any complications. If some of them are mild (dizziness, nausea, weakness and rapid fatigue), fasting can be continued. If it becomes difficult for a starving person to endure a long refusal of food, it is reasonable to stop fasting.
Fasting should be stopped immediately if one or more of the following symptoms occur:
In follows from the above that losing weight through fasting is not a way for everyone. If you choose periodic fasting for weight loss, be prepared for risks. Many select it, without assessing all the possible consequences. Not everyone is turning to specialized clinics with the proper level of inpatient conditions. Partly because they don’t realize the danger. But in many ways also because such treatment is quite expensive.
The risk of negative consequences of fasting increases if a person has eaten incorrectly for many years. People whose eating behavior is consistent with healthy eating and lifestyle can be more likely to benefit from therapeutic fasting.
The right way to weight loss and stabilization begins with the formation of healthy eating habits. The way you are used to eat depends on your internal psychological attitudes. Think, what is the problem with excess weight? Perhaps it is a habit of “stress-eating”, addiction to fast food, or irregular meals? You are more likely to come to the desired figure on the scales, realizing the root of the problem and understanding it, than if you start to fast without proper training and medical participation.
The 7Spsy behavior modification technique is one of the most effective methods of working with the mindset and improper eating behavior. This is a unique modern technique, the principles of which are based on behavioral theories of I.P. Pavlov, A.A. Ukhtomskiy, B.F. Skinner. The technology allows forming and strengthening positive attitudes on the diet schedule, choosing healthy food, giving up fast food, the ability to solve psychological problems directly, instead of becoming an emotional eater.
The program is designed for a period of 2 to 6 weeks – you can start training immediately after diagnostic testing. The course process is supervised by a behavioral psychologist. He/she will be in touch with you by phone, messenger or e-mail.