The essence of this practice is that all the time in a day (or days) is divided into intervals of complete refusal to eat and periods when a person eats normally without restriction of food and in plenty.
- a person eats nothing or very little (the interval from 12 to 48 hours is supposed);
- a person eats any foods, but they constitute his/her individual and daily calorie allowance depending on the desired result (weight maintenance, weight gain or weight loss).
The most popular variant is considered to be 5:2, where five days a week adhere to a normal diet, and the remaining two days cut calories.
Interval fasting has many different variants, including intermittent fasting, unloading days, but all are united by a common principle – a period of voluntary refusal to eat is followed by a period of eating. And then again refusal to eat. And so in a circle.
As representatives of the diet assure, it helps a lot to lose weight, as well as to improve the body. Such a food regimen may appeal to many: finally there is a way to eat everything you want, and at the same time do not be afraid to get better. And another thing: it is much easier to skip breakfast, lunch or dinner than to significantly limit yourself in the amount and calories of food.
In principle, periods of human food restriction have existed since ancient times. The first mention of medical fasting dates back to the 5th century B.C. and was found in the writings of the ancient Greek scientist and physician Hippocrates. In the Middle Ages, fasting was used to treat most diseases. Indian yogis believe that giving up food purifies the body and mind. Finally, all religions have fasting days, when only low-calorie food is consumed or complete renunciation is practiced. For example, in the month of Ramadan Muslims can eat and drink only in the dark, Orthodox Christians also periodically fast. Thus the wisdom of the ages reaches us in traditions, customs, including religious ones. And what modern scientists have discovered about the benefits of periodic fasting was known to our ancestors for a long time.
Where did it all come from? The idea of intermittent fasting gained particular traction after the discovery of Japanese scientist Yoshinori Osumi. Studying the processes of autophagy (the natural process of dissolving spent components of our cells) in yeast fungi, he noticed that periods of fasting have a positive effect on cell renewal and help slow down the aging process, for which he was awarded the Nobel Prize (!!!) in 2016. As scientists explain, the effect of interval fasting is determined by the processes that begin to occur in the body from about the 12th hour of fasting. The so-called catabolic phase begins. At this time, glycogen stores in the liver and muscles come to an end. The body begins to use fat as an alternative energy source. Blood glucose levels drop, and ketone bodies are produced, which serve as fuel for all the body’s needs. Starvation leads to changes in metabolic and intracellular processes, as well as in the level of some hormones.
It turned out that the prolonged absence of food activates in rodents intracellular mechanisms responsible for aging, includes the process of autophagy, when inside the cell disintegrate and remove harmful particles – waste products. Stimulation of autophagy is one of the effective methods of slowing down aging. In addition, energy deficiency protects genetic material from mutations, and therefore reduces the risk of cancer.
But prolonged starvation gradually depletes the body of vital nutrients and reduces muscle mass.
Then a consensus was found: it turned out that all the above-mentioned health benefits are preserved even with incomplete, but intermittent fasting, when from about 12-14 hours you stop eating and then return to your normal diet for a certain period of time.
Pros of intermittent fasting
This is how the method of Intermittent fasting was born – interval fasting, which triggers autophagy mechanisms and preserves all the beneficial effects of fasting: normalizes weight, reduces sugar and cholesterol, inhibits the aging process, reduces the risk of cancer and neurodegenerative diseases. At the same time, a person physically and psychologically does not experience significant suffering, because in the nutrition window can eat almost anything he wants.
And, unlike rigid diets, in such a mode can be very long without harm to health.
Many diets are based on the refusal of certain products, which means that they limit the intake of nutrients important for health. Because of calorie counting, torture in the gym and deprivation of favorite foods, the brain is in constant stress. As a result, in the pursuit of a slim body you get gastritis, depression and decreased immunity. Doctors have long been talking about the harm of diets and the benefits of a rational diet combined with adequate physical activity.
Once again, let me emphasize! Intermittent Fasting is not a diet, but a food regimen that you can follow for a long time, literally your whole life.
Its effectiveness for weight loss has been repeatedly proven by various studies, and the added bonus is health, youth and active longevity by activating the autophagy process.
Disadvantages of interval fasting
Every body is different, so the methodology of interval fasting is not suitable for everyone.
When following this food regimen, the following negative effects have been noticed in some people:
- Prolonged interruption of eating contributed to increased levels of cortisol (stress hormone), which increases plasma ghrelin levels, suppresses satiety, accelerates gastric emptying and makes you consume more food, therefore, contributing to fat storage. Cortisol also in high concentrations weakens the immune system;
- Prolonged refusal to eat can lead to headaches, stress, stomach and intestinal discomfort, heartburn and belching;
- Disturbances in the female cycle. It has been experimentally observed that interval fasting is more effective for men than for women. Experiments on animals have demonstrated that starvation reduces the fertility of females and even provokes infertility. The data on humans is quite contradictory. Some women have no side effects, while others claim to have gotten irregular cycles, weakness and amenorrhea, which recovered after interval fasting was canceled. In addition, it has been found that women feel hunger more acutely because they produce the hormone ghrelin more actively. Thus, you should use this dietary regimen with caution, especially if you have reproductive problems;
- Sleep disorders (decreased duration of REM sleep phase);
- There may be a decrease in insulin sensitivity, which can lead to diabetes;
- Hair loss.
One TREA clinical trial showed that for people diagnosed as obese, interval fasting did not work at all, they did not lose weight or improve their metabolism.
Who should not use intermittent fasting?
The main contraindications for Intermittent fasting are:
- gastric diseases;
- diseases of the gallbladder (in case of prolonged practice bile stagnation and development of gallstone disease is possible) and adrenal glands;
- diabetes mellitus, hypertension, gout;
- Body mass index less than 18.5 (very thin);
- eating disorders;
- pregnancy and breastfeeding;
- Regular use of medications tied to meals;
- Under 18 years of age.
A person should eat little, preferably not often, not make a cult out of food and not consider it the meaning of life.
