Is fasting safe

What if fasting is part of our genes? After all, it is the fruit of evolution and what has allowed us humans to go through the ages. Our ancestors probably didn't sit their buttocks at the table 4 times a day, they had acquired the ability to store reserves and use substrates very efficiently, in order to cope with food shortages.

Fasting is a thousand-year-old practice, its oldest testimony dates back to the 13th century BC! In 370 B.C., Hippocrates himself advised fasting.

Fasting is therefore a slow legacy of evolution, a legacy that many people continue to perpetuate in developing countries or in certain religions (Ramadan is a form of fasting, called partial fasting). Fasting is defined as a voluntary or involuntary absence of food, which begins from 6 hours after the last meal taken. There are several forms of fasting, including complete fasting, fasting, intermittent fasting and religious fasting, in addition to all methods of fasting.

Before attaining enlightenment, Buddha himself is said to have fasted for 6 years during which he consumed very little food (this is why the image of a wrapped Buddha is wrong). Some consider him to be favorable to meditation.

But if many adopt it, it is no more for meditation than for slimming down.

Indeed, in recent years, fasting has become a very fashionable diet. We have come to ask ourselves the following question: "What if the problem with diets is not so much focusing on 'what to eat' but more on 'when to eat'?

It's a bit like the concept of fasting, the other name for fasting.



To begin with, I think it is important to remember how the human body works.

Deprived of food for several days, the body faces the lack of fuel by tapping into its resources :

• on the first day without food, it draws first from the glucose available in the blood, then from the liver, in the form of glycogen.
• on the 2nd day, the reserves are exhausted, the cells then draw from adipose tissue (fat reserve) and some cells will draw from muscle tissue to transform proteins into glucose (phenomenon of neoglucogenesis).
• On the 5th day, the body enters a phase where it seeks to save its protein stock. Liver and kidneys then make substitute molecules known as ketone bodies that can be used by the brain instead of glucose, this is called cetogenesis.





Intermittent fasting is said to be effective because it allows the body to enter its peak fat burning phase, which occurs about 8 to 12 hours after a meal. This helps you lose body fat without sacrificing muscle mass. When you follow a typical breakfast, lunch and dinner schedule over a 12-hour period, it does not allow the body to reach this threshold.

Typically, when you eat a meal, your body will spend a few hours burning what it can from the food you have eaten. Since it has all this at hand, it is easy for it to burn energy in the bloodstream, and your body will choose to use that energy rather than the fat you have stored. This is especially true if you've just eaten a meal rich in carbohydrates and sugar, because your body prefers to burn sugar as an energy source before any other source.

During a period of fasting, your body does not have a recently consumed meal to use as an energy source, so in theory it is more likely to draw from the fat stored in your body, rather than the glucose in your bloodstream or the glycogen in your muscles/liver. All of this results in burning more fat.

The hypothesis is therefore that fasting would, for the same number of KCal, be a more effective weight loss technique compared to others. This brings us to the benefits of intermittent fasting.




Fasting to lose weight?

The main reason why most people try intermittent fasting is to lose weight and not to reach their boddhi as buddha.

Some practice it at equal Kcal while others add a caloric deficit, as in any good diet. As mentioned, intermittent fasting helps further, as it allows the body to reach its peak fat burning, allowing your metabolism to function optimally.

Research has shown that the 5:2 fasting protocol (two fasting days in a week), limiting calories to only 500 to 700 per day over two days a week, seemed to be the most effective for weight loss. A 2013 British study found that participants who regularly reduced their daily caloric intake became more sensitive to insulin and lost more weight compared to those who followed a more typical diet.

The research also showed that fasting can increase Human Growth Hormone (HGH) by 1,300% in women and 2,000% in men.

Human Growth Hormone is produced naturally by the body, but remains active in the bloodstream for a few minutes. It is known to play a role against obesity and help build muscle mass, important for fat burning (more muscle = more fat burned).

Intermittent fasting improves hormone function to facilitate weight loss, lowers insulin levels, increases growth hormone levels and norepinephrine levels: all factors that ultimately contribute to the breakdown of body fat.

Short-term fasting has been shown to increase the metabolic rate by 3.6 to 14%, which helps burn even more calories. In a scientific study conducted in 2014, researchers found that intermittent fasting can lead to weight loss of 3 to 8% over a period of 3 to 24 weeks, not bad!

In conclusion, is fasting a good method to lose weight? Possibly, but be careful of the long-term effects. Certainly we will probably lose weight, but when it comes to stabilizing, it will be another pair of sleeves and re-feeding will probably be difficult. As for athletes, we generally note a low impact on performance, that being said, it is not at all advisable for high-level athletes. Don't think about fasting while preparing for a major event such as a marathon. Very thin people should not fast either, you could trigger anorexia nervosa.

Finally, keep in mind that fasting is by no means a pleasure, if you already don't like restrictive diets, expect to be hungry...very hungry!





Fasting to stay young?

Beyond weight loss, some people have made fasting an integral part of their lifestyles, and no doubt its potential ability to prolong life would not be unrelated to it.

However, although promising studies have been conducted in animals, nothing has yet been done on the human side, and researchers are just beginning to understand how this phenomenon is biologically possible.

A recent Harvard study is said to have sniffed out a very serious lead by taking a closer look at the effects of fasting on mitochondrial networks. It's quite technical, I leave it to the most scientific among you to make up your own mind on the matter.

Multiple studies in rats have shown that these effects are similar to the benefits of continuous caloric restriction. In some research, experts have seen dramatic results, for example, rats that fasted every other day lived 83% longer than non-fasting rats.

Although more research on humans is needed, there is every indication on health markers that fasting may extend life expectancy, again conditionally.


Fasting to lower cholesterol levels?

A meta-analysis has recently come out on this subject and here is a summary of it.

"Normal, low-calorie intermittent fasting can be a dietary method to help improve the lipid profile in healthy, obese and dyslipidemic men and women by reducing total cholesterol, LDL, triglycerides while increasing HDL levels.

However, the majority of studies that analyze the intermittent impacts of fasting on lipid profile and body weight loss are based on observations in the specific setting of Ramadan fasting, which lacks a large sample size and detailed dietary information. Randomized clinical trials with a larger sample size are needed to evaluate the effects of fasting, mainly in patients with dyslipidemia."

What we must remember from fasting on this subject therefore :

• that it can be a method to help improve the lipid profile in healthy, obese and dyslipidemic men and women.
• that it tends to reduce total cholesterol levels, as well as LDL ("bad" cholesterol) and triglycerides while increasing HDL ("good" cholesterol) levels.
• that the majority of studies analyzing the impact of fasting on the lipid profile are carried out during the Ramadan period, which is not perfectly similar, so be wary.


Fasting to reduce your risk of diabetes?

It seems that fasting helps reduce the body's insulin, the first hormone responsible for converting glucose into fat.

When we fast, we consume less glucose and our insulin stores drop. But the body wants to maintain a certain amount of blood glucose when needed. This is where glucagon comes in, a hormone that does exactly the opposite of insulin by converting fat into glucose!

Since fasting reduces insulin levels, the body adapts and becomes more resistant to insulin, theoretically reducing the risk of diabetes. Therefore, fasting would reduce insulin levels, increase glucagon levels and burn more fat!

So how do we do it?





Some studies have compared four different types of fasting, namely the 8-hour fast (typically a good night's sleep between meals), the 4-hour fast, the 8-hour fast, and the 24-hour fast. According to the results, it would seem that the most productive formats in terms of fat and body weight reduction are the 16 and 20 hour formats. These findings were conducted at KCal equal.

In modern working conditions where many people can't eat lunch (or eat a sandwich on the go in the subway between meetings), we see that it is possible to adopt diet strategies that incorporate the right number of calories and respect the 16h youth window.

Here are some fasting strategies.

A few general rules, however, before trying :

• If you are really hungry, eat something. If you don't, you'll spend all your time being hungry and stressed at the thought of being hungry.
• If your diet is not healthy and balanced, maybe wait a little while before starting a fasting routine so that it is not something to worry about. Focus first on eating fresh, healthy foods and eating consciously.
• Are you training for a big event, like a marathon or triathlon? This is probably not the right time to try fasting! Talk to your coach and doctor first.
• If you are pregnant, diabetic or very thin...avoid.
• Finally and as always, listen to your body!


The Fasting : concretely, 20h in the evening => noon the next day without eating

This method is the French version of Leangains and was formulated by JB Rives, it is commonly called fasting. Concretely, we skip breakfast.

"OMG, no breakfast is the most important meal of the day, man!"

FALSE, it's just a meal like any other. At least that's what everything suggests now. Yes, medicine and science are evolving, and the new discoveries go against everything we've ever heard since we were kids, breakfast is not the most important meal, nor does it have a metabolism activating role. It was logical to think that it had to be big because you had all day afterwards to spend it, but it just doesn't work like that physiologically speaking...

Now, if you like breakfast, you can keep taking it, for others who tend to skip it, no worries. The risk, if you are used to it and you stop eating breakfast, is to notice a decrease in intellectual activity around 11:00 am. It's a matter of habit, the body will certainly adapt.


We stop eating at 4pm and don't start again until 8am the next day.

It is important to understand that we do not skip meals as such since we keep the same calorie total. It is not necessarily good to do it systematically, although many have integrated it into their lifestyle and practice it on a daily basis.

It can be done two days a week, for example, as part of a weight-loss diet, a common fasting format called 5:2, during which the daily caloric intake is limited to 1/4 of what is usually consumed, on two non-consecutive days a week.

Note: the young person breaks from the moment you take sugar, it is therefore advisable to drink unsweetened drinks.






Although fasting has been considered a natural, rather safe and effective method to help the body get rid of harmful toxins, it is also vital to be well aware of its possible side effects such as :

- Dehydration: during fasting, the body continues to lose salt and water through sweat, urine and breathing. If the body is not hydrated before fasting, it can become dehydrated easily. If such symptoms occur, it is essential to drink water mixed with salt and sugar to make up for the loss.
- Headaches that may be caused by hunger, restlessness, or a sudden lack of caffeine or nicotine in the body. Drinking plenty of fluids, eating in moderation and avoiding direct sunlight can help prevent headaches.
- Hypoglycemia: Diabetics should be very careful and should always discuss fasting with a health care professional before starting. It is strongly recommended that they monitor their blood sugar levels, as a drop in blood sugar can be fatal and lead to fainting. If dizziness or sweating occurs, it is advisable to drink fluids containing sugar as soon as possible.
- Heartburn, which can be caused by the production of stomach acid. Avoiding fatty and spicy foods and eating in moderation may help control belching, vomiting and heartburn. Reducing caffeine and tobacco consumption may also be beneficial.

Always stay active, stay hydrated and eat healthy, fibre-rich foods, this will help you avoid constipation during fasting.

Other common side effects include fatigue, muscle cramps, dizziness, shivering or colds (all due to metabolic changes).

However, this is the body's natural mechanism for cleansing and repairing itself while expelling unhealthy cells. It is always advisable to discuss with a health care professional before considering fasting as a treatment option for any reason.



Be careful with this method, it is by no means a panacea and it is probably not for everyone. Everything is not as rosy as one might think, seeing everyone boasting about its benefits. You will be hungry!

Staying 16 hours without eating, can you imagine it? So we'll tell you, "yes, but the body adapts, yes, you'll get used to it... tatati tatata".

Of course, the body has the ability to adapt and we must not forget that our 4 meals a day are partly due to our culture, many civilizations function on 2 meals or even 1. Moreover, you can see for yourself that if you only provide your body with one meal a day, it will eventually get used to it and will no longer require the rest of the day.

However, if you are already struggling not to eat with a "normal" diet, you'd better spread your meals out over the day and eat more food with a high power of satiety. Especially since, like other eating plans, fasting does not exempt you from counting your calories and create a deficit, at least if you are looking to lose weight.

Nevertheless, it is a modern method that seems to prove that it is possible to perform a diet by improving the overall quality of the meals with an equal level of calories. It can also be a good solution for people who suffer from digestive disorders.

In any case, you will need to make sure that you always have enough energy for your body to function optimally and that you always have enough protein, regardless of the number of meals you eat.

This also has the merit of proving to us that it is not so bad to "skip a meal" contrary to what we have always been told. So the next time you consider having a triangle sandwich on the go or "drinking your meal" (we see a lot of ads for drinking meals because eating has become too restrictive...), why not fast instead, if you can?