Thinking of fasting? Here's everything you need to know about keeping fit while off food

After the researches prooved it's benefits, fasting and intermittent fasting are in demand in recent years
After the researches prooved it's benefits, fasting and intermittent fasting are in demand in recent years Copyright Dietician Cansu Dumanlı Berber-
By Kerem Congar
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Euronews Culture takes a deep dive into why some experts are increasingly recommending fasting as an essential way for us all to stay fit and healthy.


The Muslim holy month of Ramadan, when Muslims fast, has just ended this year. During this period, it is common to see the words "Do fast and find health" on the doors of many mosques. 

Ramadan fasting is slightly different from intermittent fasting, but both approaches are designed to have the same result, namely rest for the body and the removal of toxins.

Scientific research also suggests that fasting is beneficial for our health.

In 2016, the Japanese biologist Yoshinori Ohsumi won a Nobel Prize for his discoveries into the mechanisms of autophagy - or the human body's process of reusing old and damaged cell parts.

But why is autophagy so important for our bodies, immune system and overall health?

According to Ohsumi's research, which he carried out over 25 years, when the human body is starved for a certain period of time (usually over 12-14 hours), all cell inflammation rapidly shrinks and disappears. When humans are hungry, cells renew themselves rapidly and the effects of ageing are delayed and even lifespans can be increased.

Ohsumi's study is certainly responsible for the big increase in popularity for fasting and intermittent fasting (IF), with many doctors, dieticians and fitness trainers now recommending the practice. In some circles, it's replaced the old adage of 'eat little and often' entirely.

Of course, being hungry is not easy or particularly pleasant but, after researching the benefits of fasting for about 3 years, I wanted to share my own experiences and thoughts on adopting the practice as a lifestyle choice.

Autophagy ambitions

In simple terms, the mechanism of a cell that 'purifies and renews' itself is called 'autophagy'.

Cell renewal naturally occurs in our bodies whether we eat or not, but autophagy itself accelerates when we deny ourselves food - and can help disease heal more rapidly.

One non-randomised trial showed improved weight loss, blood sugar levels, and lipids with as little as 14 hours of daily fasting and no change in the participants’ baseline diet. Some clinicians feel their patients have more success with intermittent fasting when eating low-carb or high-protein diets, but there is currently insufficient evidence to back up these claims.

While the buzz surrounding IF is relatively recent, the practice isn’t new, with some religious cultures undertaking it for centuries. In fact, although accurate data is difficult to acquire, it's actually likely that hunter-gatherer societies and inhabitants of so-called 'Blue Zones' - unique regions across the world with the healthiest, happiest and longest-living people - have adjusted their meal frequency to one or two meals per day without any snacks for generations.

Flickr-Massa Bitar
Intermittent fasting is in demand in recent years.Flickr-Massa Bitar

A scientific history of healing

Great medicine pioneers like Hippocrates, who lived between c.460 BC and c.370 BC and Avicenna, who was born in 980 AD and died in 1037 AD, both agreed that being hungry for a certain period of time is good for the health of the human body. Hippocrates was in favour of a 3-day healing fast, while Avicenna recommended fasting in order to recover for a period of three weeks or more. As medicine became more modern, the IF method became history - but it cropped up again at the end of the 19th century.

Today, as Turkish dietician Cansu Dumanlı Berber explains, "One of the most common methods applied in intermittent fasting is the 16:8 model. However, 18 to 6, 20 to 4, and one meal a day' models are also preferred. If you want to do intermittent fasting, it would be much healthier to start with a model that you determine for yourself and make this model sustainable".

Berber also highlights the impressive night time effect of intermittent fasting on human metabolism, explaining, "In the evening or late at night, the body has to use its energy on digestion, instead of renewing itself. In addition, since long fasting periods activate the autophagy mechanism, it creates an environment for damaged cells to be able to recover and removes toxins from the body”.

30 percent of the body's energy is used to produce enzymes and acids necessary for digestion.

The Ukrainian doctor and biologist Aidin Salih explained in her 2007 ‘Gerçek Tıp’ (or ‘Real Medicine’) book how intermittent fasting and water fasting can help to heal the body.

"While fasting, the immune system does not deal with digestion since no outside food comes into the body”, she said, “Because 30 percent of the body's energy is used to produce enzymes and acids necessary for digestion. When we are hungry, the immune system directs all its energy to cleanse the body".

Fasting to stay fit and to fight flab

Technically, fasting burns stored fat, melts excess weight, and clears impurities from the body. Because most people live in cities, we cannot escape pathogens that cause inflammation in the body. We are also victims to, among others, polluted air, chlorinated water, foods with additives, plastics penetrating the beverages and foods we eat and drink. Heavy metals often used in industrial agriculture are also increasingly believed to be among the factors that make the human body unhealthy.

While fasting, the body enters the cleaning process quickly
Aidin Salih
Doctor, Biologist and phytotherapıst

In her book, Salih explained, "When fasting continues, the blood is completely cleansed on the 3rd and 4th days. Clean blood begins to dissolve the cholesterol, toxin, and lime layer formed on the walls of the veins, thereby removing it from the body”.

5-7 days long fasting periods can rapidly destroy cancer cells

In line with Yoshinori Oshumi's research, Salih also stated that fasting can rapidly shrink and destroy cancerous cells. She explained that if a human extends the practice of intermittent fasting for a longer period of time, the immune system has the ability to clear and destroy even cancerous cells without any medication, chemotherapy, or surgical intervention.

According to Doctor Salih, between the fifth and seventh day of fasting, the body switches to internal nutrition. Since cancerous cells cannot receive signals from the brain and are starved for a long time, they can possibly destroy themselves. Since the energy in the body is low during fasting, healthy cells use the energy and protein released by the explosion of cancerous cells to perform autophagy. During this starvation period, while healthy cells are rapidly regenerated, cancerous cells are, in theory, able to disappear.

The human body is primed for intermittent fasting


In research by biologist Sinan Canan, it’s claimed that the human body is naturally programmed to endure long periods of hunger.

In his series of books ‘Humans' Factory Settings’ (or İnsanın Fabrika Ayarları), Canan explains that humanity now has more easy access to food than ever before in history, but many of the foodstuffs we consume contain additives to extend their shelf life. He claims this creates a significantly worse picture for the modern human compared to our ancestors who were hunters and gatherers or engaged in farming.

Intermittent fasting was part of the daily lives of ancient people.

Thousands of years ago, hunters and gatherers could only eat whenever they could find food and spent most of the day hungry. The process of hunting and gathering also helped humans to burn a lot of energy and they rarely took in more calories than they needed. Add to this the absence of processed foods and it’s easy to understand the lack of inflammation in the bodies of our ancestors.

The acidic value of the body increases as we eat; fasting regulates the body

If we look at intermittent fasting from another angle, we can see that many foods negatively change the acid-alkaline balance in our bodies. The aggravation of diseases and the ageing process actually progress in direct proportion to the acidic value of the body.

Renowned Turkish doctor Canan Karatay explains, "If we constantly consume foods with high acidity and our body cannot resist this situation after a certain period of time, our liver will become fat and cause many diseases. Foods high in sugar and carbohydrates quickly increase the acidity in the body".


Most of the food consumed nowadays contains sugar and carbohydrates - and that even includes fruits, regardless of whether they are natural or organic. Studies have shown that fasting or intermittent fasting is the speediest way to reduce the negative effects of these foods that can increase the body's acidity.

Fasting expert Zaza Yurtsever recommends intermittent fasting in a slightly different way. He suggests that, for best results, eating only light foods like fruits and vegetables for a period of about 10 days. For the following five days, only herbal teas, water, fruit, and vegetable juices are drunk and no solid food is to be consumed. He says this can cause the body to rest and toxic substances and fats can be quickly destroyed.

These long-term starvations we create also have a reducing effect on abdominal fat, especially as they improve insulin sensitivity in a positive sense.
Cansu Dumanlı Berber

What are the types of intermittent fasting? How is it applied?

The 16:8 rule is the most common approach. This means fasting totally for 16 hours and only eating within a period of 8 hours. For example, you could choose to stop eating at 6pm and have your first meal the next day at 10am. There are many other variations of this such as the 14:10, 18:6, and 20:4 methods, which can be adjusted to suit your daily life.

OMAD - or “one meal a day”. As it sounds, this means eating only one meal for the entire day with no snacking. You can drink herbal teas, coffee, or water but they must not contain any sugar.

Alternate-Day Fasting (ADF). This is a kind of water fasting that lasts about 36 hours. For instance, you could finish eating at 7pm Monday, not eat at all for the entirety of Tuesday and have your first meal on Wednesday morning. This approach doesn’t exclude liquids, as long as they are free from sugar.


The 5:2 approach. In this practice, you can eat normally for five days during the week and fast entirely or eat very few low calories for the remaining two days. The two days do not have to be consecutive.

Cansu Dumanlı Berber explains that it was the discovery of autophagy's positive effects on the body that caused experts to recommend fasting and IF, saying, "Intermittent fasting is a diet model in which we take all the calories we need to take daily in a certain time interval of the day and we do not take calories in the remaining hours of the day and therefore we starve. The hunger period that we create, especially at night, is very effective in fat burning. These long-term starvations also have a reducing effect on abdominal fat, especially as they improve insulin sensitivity”.

Water consumption is a necessity during fasting

Remember, fasting or intermittent fasting might mean lessening your food intake, but it’s still important to drink liquids. There are endless studies on how consuming less water can cause great harm to the body - but a human can live for about 40 days without eating. In contrast, the average person will die if they don’t imbibe water for as little as 4 or 5 days. Staying well hydrated is an important part of succeeding with intermittent fasting.

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