Periodic starvation (Fasting)

Periodic starvation

Periodic starvation

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Periodic fasting, as a principle of nutrition, has been known since ancient times. The mention of curative starvation occurs in the Bible more than 70 times. Many famous philosophers and scientists, such as Socrates, Plato, Pythagoras, practiced starvation in order to improve their health and lived a long enough life – about 90-100 years.

In the 70-80s of the 20th century, medical starvation again began to gain popularity. A lot of discussions were caused by Paul Bragg’s book The Miracle of Fasting, thanks to which many learned about the benefits of this method of nutrition for health.

Basic schemes of periodic fasting

The main schemes of periodic fasting are several of the most common options:

  • 16/8;
  • 20/4;
  • 24 hours of hunger;
  • 36/12;
  • casual meals.

Consider these schemes of eating within the framework of periodic fasting in more detail.

Scheme 16/8

Scheme 16/8 implies 16 hours of fasting and 8 hours of nutrition. This is a fairly common form of periodic starvation for massonabora, used in practice by many modern athletes.

According to this scheme, the most optimal time for hunger is a time interval from 21 pm to 13 hours of the day. After an hour of the day and until nine in the evening it is recommended to eat at least 2-3 times.

This principle of fasting includes mandatory morning exercise on an empty stomach (until 13.00 hours), during which it is allowed to consume 10 grams of amino acids BCAA.

The first meal after exercise should be the most abundant and rich in useful complex carbohydrates. Follow-up meals should decrease in volume and amount of carbohydrates and end exactly at 21 pm on the same day. Then the scheme is repeated daily.

periodic fasting
periodic fasting

Scheme 20/4 or the warrior’s diet

This scheme provides  20 hours of hunger and 4 hours of nutrition is a more advanced scheme of periodic fasting. It was called the “Warrior’s Diet”, thanks to the book by Ori Hofmekler, where the author describes in detail the principles and characteristics of the low-carb diet.

This principle of nutrition implies the exclusion of food for 20 hours on a daily basis. During this period, it is desirable to completely limit the consumption of food, except for light vegetables and certain protein products.

Evening training should be preceded by eating and passing on an empty stomach. It is recommended to eat for 4 hours, as a rule, it is one full-fledged evening meal or two medium meals. But in this case, there are no restrictions on the quantity and quality of food. The warrior’s diet implies a tight dinner of absolutely any kind of food of your choice.

periodic fasting
Periodic fasting

Scheme of 24-hour fasting

Driving 24-hour fast for 1-2 times a week is the most common among athletes who adhere to a low-carb and high-protein diet at the same time as the lack of food during the day 1-2 times per week must be compensated by the use of large amounts of protein foods during food.

To achieve optimal results, this scheme of nutrition imposes a restriction on the use of simple carbohydrates and processed foods.

Scheme 36/12

Scheme 36/12 includes 36 hours of hunger and 12 hours allocated for eating. According to this scheme, meals take place every other day. For example, on Monday, meals are distributed from 8 am to 20 pm. Further all night and all Tuesday food is absent. In the period from 8 o’clock in the morning to 20 o’clock in the evening of Wednesday again it is possible to eat.

During periods of the “food box”, the food entering the body should be as useful and balanced as possible on the basis of the ratio of proteins, fats, carbohydrates and calories. Nevertheless, several times a week you can afford to eat what you want. This power scheme is the most difficult to observe and rarely used by beginners.

Periodic fasting
Periodic fasting

Scheme of casual meals

The scheme of casual meals implies the skipping of meals during the day in an absolutely random order. Supporters of this scheme of periodic starvation suggest eating and training, regardless of any diet, based only on their own feelings and instincts.

Nevertheless, the daily diet in this diet should be based on the paleo diet, which, in turn, imposes certain restrictions on the use of certain products. Food is allowed for the consumption of protein products, vegetables, fruits, berries, nuts and seeds. Caloric content of the diet is not limited. Nevertheless, in accordance with this diet, several times a week to skip one of the meals.

Who is this diet suitable for?

Best of all, periodic starvation works for people and athletes who are in good physical shape and want to bring muscle to dryness.

In other words, the schemes of periodic starvation can well be used by athletes “on drying” in combination with training.

Most men well tolerate the scheme of periodic fasting – 16/8, for women the most acceptable is the scheme – 14/10.

Contraindications to starvation

Periodic fasting categorically does not fit several categories of people, namely:

  • pregnant women;
  • nursing mothers;
  • people with digestive disorders.

Periodic starvation for weight loss is difficult to tolerate men with a percentage of subcutaneous fat – more than 15, and women with a percentage of subcutaneous fat – more than 22. For these people, other ways of eating with the goal of losing weight will be more acceptable.

This variant of the organization of meals can not be considered a complete alternative to a healthy diet, since it can negatively affect the health status. This type of food is suitable for reducing excess body weight only if the individual scheme of periodic fasting is carefully selected.

Men suffer from periodic fasting easier than women. The hormonal background of a woman’s periodic fasting can cause serious harm. Women should choose more sparing schemes of periodic fasting for weight loss, or completely abandon this diet in favor of a normal healthy diet with physical exertion.

Principles of periodic fasting

This diet, which all the others, has its own principles of organizing a diet and diet. Let’s consider the most important of them.

Orientation to personal needs

Numerous studies confirm the use of periodic fasting. However, depending on the individual needs of a particular person (fat burning, muscle corset maintenance, prevention and treatment of diseases), the number of hours of hunger and nutrition can vary.

At the moment, scientists are conducting research in this area, and it is possible that in 10 years we will get the optimal scheme of starvation, which in the shortest time will bring us closer to the desired result. But today it will be much more correct to use the approach to periodic starvation from the point of view of own needs, set goals and sensations.

Individual approach to the choice of scheme

Even if the technique provides for fasting through the day for 36 hours, it is absolutely not necessary to strictly follow these recommendations. It is possible that in your case it will be enough for one 36-hour hunger period per week. Especially if you are actively training or are in a stressful situation (for example, get sick).

periodic fasting schedule
Periodic fasting schedule

Distribution of periods of fasting and eating

Many supporters of periodic fasting assure that a prolonged fasting of about 36-40 hours affects the body more positively than short intervals without food.

But not everything is as straightforward as it seems at first glance.

Too prolonged interruptions in nutrition can have a very negative impact on the quality and health of muscle mass, as well as on human performance, leading to a deficiency of vitamins and trace elements in the body.

Therefore, athletes interested in good physical fitness choose not very long intervals (16-20 hours) of hunger followed by training and meals within 4-8 hours after it. This approach offers the following advantages:

  • First, strength training on an empty stomach can lead to an artificial creation in the body of a condition characteristic of a long period of fasting.
  • Secondly, the intake of food immediately after exercise promotes the most complete assimilation of nutrients, vitamins and trace elements, which, in turn, leads to a better muscular recovery.

Do not get hung up on one starving scheme, if it does not suit you at all. Try another option or take a small timeout. The main thing is to keep a sensible approach.

Autophagy as a result of fasting

Talking about periodic starvation as a process extremely useful for a person, one can not help saying that the main reason why hunger is so important and necessary for the human body is about cellular autophagy.

In 2016, a molecular biologist from Japan, Yoshinori Osumi, received the Nobel Prize in Medicine and Physiology for discovering the mechanism of cell autophagy. This phenomenon has been known in scientific circles since the 1960s, but it has been studied extremely superficially.

Dr. Osumi’s research allowed us to look at the processes of autophagy in more detail and comprehensively, fully confirming the need for fasting in order to strengthen and improve the body at the cellular level. This event stirred the unprecedented public interest in the issue of periodic and curative fasting.

Asylum Seeker
Asylum Seeker

Autophagy in Greek means “self-eating”. This is a process aimed at destroying the protein and internal components (organelles) of the cell in conditions of nutrient deficiency with a view to their reuse for energy.

At the moment, there are three types of autophagy:

  • microautophagy;
  • macroautophagia;
  • chaperone autophagy.


Microautophagy is directed to the capture of macromolecules and fragments of cellular structures by lysosomes (organoids of cells with acidic medium, responsible for the process of digestion in the cell). This process is activated by digesting the protein in conditions of energy deficiency or building material in the cell. Nevertheless, the process of cellular microautophagy is very indiscriminate and can occur under normal conditions – beyond nutrient deficiencies. For example, there are cases of partial microautophagy of the cell nucleus in yeast without loss of cell viability.


The process of macroautophagy is as follows. Part of the cytoplasm containing some cell organelles is separated by a double cell membrane and forms an autophagosome. Further autophagosomes are combined with lysosomes and digested inside the cell. Thanks to this process, the cell gets rid of obsolete or damaged organoids.

Shaperon’s autophagy

Chaperone’s autophagy occurs due to stress, for example, with prolonged fasting or increased physical exertion. In this type of autophagy, the partially destroyed protein enters the lysosome cavity and is digested there. This type of autophagy is characteristic only of mammals.

Thus, autophagy is a natural way of getting rid of cells from unnecessary and “obsolete” organoids, as well as a means of renewing the body as a whole.

Results of practical experiments

In order to better represent and familiarize readers with the system of periodic starvation, we present the data of practical experiments conducted by Dr. John M. Berardi, doctors Christie Scott-Dickson and Nate Green, involving a real participant in the experiment – men aged 37, 173 cm tall and weighing 86 kg, with a fat percentage in the body – 10%.

His sports results: bench press – 160 kg, deadlift – 205 kg, vertical jump – 81 cm, running at 36.6 meters – 4.9 seconds.

The objectives of the subject were:

  • improving their speed and strength;
  • getting rid of 6-9 kg of body weight (mainly due to fat deposits);
  • preservation of muscle mass;
  • improvement of health status in general.

It should be noted that the subject is a healthy man, a fitness trainer with 20 years of experience in proper nutrition and training.

Diet of periodic fasting
Diet of periodic fasting

Experiment number 1: 36-hour hunger once a week

At this stage of the experiment, fasting was carried out once a week – on Sunday.

On weekdays from Monday to Friday, the caloric intake decreased by 500 kcal from the usual diet and amounted to 2500 kcal per day. On Saturday, the calorie content of the diet increased sharply and was not practically limited (about 5000-6000 kcal for 5 meals). But before each meal, the subject performed 100 push-ups, because he believed that the pectoral muscles lagged behind in development from the rest of the muscle groups.

During the week (from Monday to Friday), the diet consisted only of protein and low-carbohydrate foods: meat, fish, vegetables, legumes, nuts. Every day, the subject took 1 tablet of multivitamins, 4000 IU of vitamin D, 1 tablespoon of fish oil and 10 grams of BCAA amino acids before training.

On Saturday, the subject consumed food rich in carbohydrates without special restrictions and stopped eating at 22 hours until 10 am Monday (36 hours of hunger).

The subject conducted training five times a week according to the following scheme:

Day of the week Type of load Duration of training
Monday strength training on the upper body 45 minutes
Tuesday running (sprints) 10 minutes
Wednesday circular training on the upper body 45 minutes
Thursday running (sprints) 10 minutes
Friday strength training on the lower part of the body 45 minutes

For 8 weeks the participant of the experiment lost 5.5 kg in weight. The first 2 kg were gone in the first week, then the body lost mostly liquid. Further weight loss stabilized at a level of 500-900 grams per week.

About 60% of the lost body weight was fat, 40% – dry weight, but the subject of his own state and strength indicators tends to the version that 40% of the mass is water, since a large amount of protein consumed for 6 days a week, was sufficient to maintain muscle mass. Force indicators have not changed. The weight of the subject was 81 kg.


  • 36-hour fasting once a week brings good results, but the weight decreases at the same rate as with a low-calorie diet.
  • The state of health and the general physical form were better than with an ordinary low-calorie diet.
  • The general composition of the body, power and speed indicators improved.

 Experiment number 2: fasting 2 days a week

The following experiment with fasting 2 days a week was carried out immediately after the first. Since weight loss decreased markedly, the fasting program required more radical measures.

Usually, when slowing down the process of losing weight, it is recommended to increase physical activity for 30 minutes a day, or to reduce the total calorie content of a daily diet by 200 kcal.

But in order to continue the study, a more radical path was chosen – two hungry days a week.

The regimens of nutrition and training remained the same, the only change was that the subject was now starving on Wednesday and Sunday.

This regime of hunger / nutrition led to the loss of another 3.5 kg of body weight, 2 kg of which fell on muscle mass. The participant of the experiment felt extremely exhausted and weakened. The body weight was 77.5 kg.

Then it was decided to revise the starvation scheme and add before calorie on Wednesday a high-calorie diet on Tuesday (5000 kcal per day) until 22 hours with 100 push-ups before each meal.

The body weight did not change, but stabilized at the level of 77.5 kg. Nevertheless, the state of health improved, but the tolerability of days without food became worse – the subject constantly waited for high-calorie days.


  • The scheme with 2 days of fasting subjectively did not fit our participant in the experiment.
  • If the scheme with 1 hungry day a week does not give results, do not change the fasting schedule dramatically and do not make radical changes. It is possible that an increase in low-intensity physical activity (for example, walking or slow running) for 30 minutes a day will give good results.

Experiment number 3: fasting according to the scheme 16/8

Every day the subject was starving from 21 pm to 13 hours the following day. At the same time the ascent was at 8 am, then at 9 and 11 o’clock he consumed green tea, at 12 o’clock in the afternoon training was conducted (during which 10 grams of BCAA amino acids were allowed). At 13:30, 16:30 and 20:30 – the subject used to eat. Before each meal is 100 push-ups. And from 21 pm – starving.

The scheme of training as a whole remained the same. The total daily calorific value on Monday and Friday was – 3,200 kcal. And on other days – 2200 kcal. In days with low physical activity it was supposed to adhere to low-carbohydrate nutrition.

For the first 4 weeks, the body weight of the subject increased by 2 kg and amounted to 79.5 kg. A general assessment of the physique made it possible to conclude that the main set fell on the muscles, because thanks to the increased intake of carbohydrates (in comparison with the previous scheme), the muscles were filled with glycogen and water.

However, in the first two weeks, all signs of deterioration were observed: persistent attacks of hunger, low mental concentration, mood changes in the first half of the day (up to 13 hours). Sometimes after awakening and until the training (from 8 am to 1 pm), the subject could not concentrate on his work, and sometimes his speech became very slow, there was excessive irritability over trifles and inadequate response to innocuous comments. That allowed to draw a conclusion about the loss of emotional stability during the first two weeks of periodic fasting.

Two weeks before the start of the first phase of this experiment, the emotional state and general well-being improved and stabilized. A new way of life and a diet has no longer created inconvenience to the subject. Moreover, the subject began to note a certain fullness of muscles (although the body weight increased no more than 2 kilograms), and his body began to look more athletic, in comparison with the previous two weeks after the start of the experiment.


  • The subject was approached by a scheme of periodic starvation – 16/8, but with small individual adjustments.
  • Especially difficult were the first adaptation 2 weeks of the experiment.
  • The state of health worsened with a body weight below 77.5 kg, and the body began to reduce the level of physical daily activity, there was a feeling of apathy for training and general fatigue.
  • In the future, it is desirable to stick to the daily calorie content of 2500 kcal. In days with intensive training, you can consume up to 3,200 kcal.

General results of the study

Summarizing the overall result of the study using different schemes of periodic fasting, we get the following result:

  • The body weight of the subject at the end of the experiment was 78 kg (ie, decreased by 8 kg).
  • The percentage of subcutaneous fat – 6% (decreased by 4%).
  • Weight stayed for 4 months in the range of 77-78.5 kg.
  • The testosterone level was 23.8 mmol / l (decreased by 5 units).
  • The level of tirotropin is 1.21 mlU / l (decreased by 0.4 units).
  • The level of hemoglobin – 140 g / l (decreased by 14 units).
  • The number of erythrocytes, leukocytes and platelets in the blood decreased.
  • The total level of blood lipids (total cholesterol, triglycerides and low and high density lipids) increased. This is a negative consequence, which could well be caused by increased consumption of meat and fatty foods on days with a free diet and high-calorie nutrition along with a reduction in carbohydrate intake. To prevent this phenomenon in the diet should be added more fresh vegetables and fiber and reduce the amount of fatty foods.
  • The total level of thyrotropin and testosterone in the blood remained within normal limits, but decreased. This decrease is typical for men who adhere to a low-calorie diet with a deficiency of carbohydrates.

Advice to athletes

Do not exceed the level of general stress.

Any diet, let alone hunger – a serious physiological stress for the body. Try to take into account the general level of stress during fasting in diseases, domestic problems and in training – not exceeding the permissible limits. If you feel bad physically or mentally – just relax and skip the training.

Diet of periodic fasting
Diet of periodic fasting

If fasting produces good results, do not overdo it.

Try to make periods of fasting manageable, short and periodic. Do not practice periodic fasting for more than 4-5 months. Be sure to take breaks.

Make your workouts easier.

When observing the fasting scheme with the restriction of the total caloric content of the diet on days with meals, your body is experiencing an acute energy deficit, so training in this period should take place in a sparing regime.

  • Strength training – no more than 3-4 hours a week.
  • Interval (circular) training – no more than 2-3 short sessions per week.
  • Cardio training (only if necessary) – no more than 1-2 hours per week.

Find the best combination.

On the contrary, long-term low-intensity training is perfectly combined with many schemes of periodic starvation. If you want to qualitatively transform your body and reduce the amount of subcutaneous fat, you need to increase the amount of daily physical activity.

Do not be fooled!

Do not expect that you will lose weight if you just skip breakfast, and at other times eat as usual. Periodic fasting is full control over the consumption of nutrients (proteins, fats, carbohydrates), careful selection of products and mandatory training on an empty stomach.

Attention to crossfitters!  You should pay special attention to the use of periodic fasting for weight loss or weight gain. Since high-intensity training for the development of endurance and strength is completely incompatible with starvation and can harm the body!

Hormonal reactions to diet

As shown by practical experiment, periodic starvation affects not only fatty deposits, but also the whole organism as a whole. Accordingly, affects the hormonal background.

When switching to starvation according to the scheme two hungry days a week, there can be a decrease in the production of sex hormones: testosterone, DHEA (dehydroepiandrosterone), LH ( luteinizing hormone), FSH ( follicle stimulating hormone).

Influence on men

For a man, such a change in the hormonal background is fraught with sharp mood swings, constant fatigue, reduced levels of efficiency, muscle loss and a general loss of energy. But after restoring the former high-calorie diet with lots of protein and fat, the hormonal background quickly recovered.

Influence on women

For the female body, periodic fasting (for two or more days a week) in combination with physical activity can cause much more significant damage to the hormonal background.

In general, the female body responds more sensitively to changes in diet. Therefore, the approach to diet and training for women should be very literate. In one experiment, a 35-year-old woman fasting for two days a week, combined with intense training and a high level of general stress, the overall hormonal background deteriorated sharply. The levels of estrogen, progesterone, DHEA (dehydroepiandrosterone), LH / FSH (luteinizing / follicle-stimulating hormone) were almost equal to zero. Monthly stopped. Restoration of hormonal background in the participant of the experiment was very slow.

Diet of periodic fasting
Diet of periodic fasting

Therefore, in healthy people with a normal hormonal background, periodic fasting should be applied very carefully and deliberately, and the periods of hunger themselves should be short (up to 16-20 hours).

Periodic fasting can be useful for people with insulin sensitivity problems and some other hormonal problems, especially in the polycystic ovary syndrome in women and excessive aromatization of testosterone in men.