In our previous articles, we talked about the diet of our Neanderthal ancestors and the fact that most foodstuffs we are eating nowadays appeared only in the last 100–200 years. And that practically all our modern foods, so rich in carbohydrates and bad fats (trans-fat and too many Omega 6), are a favorite forage of harmful and pro-inflammatory bacteria which are a primary cause of many serious illnesses. Today I propose to summarize all these data and try to understand if there is an ideal or optimal diet that would allow people not only to stay healthy but also live long. Is such a diet, in your opinion, possible, at all? And if yes, what should it be?

The answer to this question directs us at the heart of medicine as we must understand how things we ingest affect the way our body works, how our cells work, and which dysfunctions can explain diseases. You must also understand how life has begun on earth and what is the purpose of life. And understand biology and biochemistry of living cells. It’s quite complicated and we need to integrate a bit of philosophy.

Why should we talk about philosophy in medical purposes?

First: my approach is holistic. To answer the question of how our cells function, we should think about what life means for Nature: reproduction. Nature wants us to pass our genes to the next generations. So, the important things for Nature are our genes, only our genes, not us! Our body (the soma) is the protection “wrap” for our genes. When our genes are passed to the next generation, nature does not care anymore about us. But we care, we want our body to live long and be healthy, and I think that this is in contradiction with what Nature created.

Second, look around… we are not alone, we live together with other animals, plants, and micro-organisms, and there are many important interactions between us. We discussed it in our previous article about bacteria and their role in our health. Do not also forget that the tiniest organelles producing most of the energy in our cells (mitochondria) are a sort of bacteria that our ancestors’ cells “ate” billions of years ago for cooperation in order to survive: “I will protect you and you will generate energy for me…”

Third: Nature (and our bodies) are the cleverest and most fascinating “machines” ever done. They are able to understand that when there is food available it is time to divide and to reproduce and when they are in a fasted state, it’s time to repair and to reinforce themselves to be ready for the moment when they will be able to reproduce. Do the words “division”, “reproduction” and some health problems like cancer sound familiar to you?

Frankly speaking not in the context of the diets, healthy food and longevity.

However, this is the case. Health problems have a direct link with the mechanism of cell division and repair which are directly related to nutrition. Many studies, over the years, have confirmed that our health depends mostly on what we eat. Because our genes expression is controlled by our meals and mealtimes. Said in other words, depending on what you eat, your genes do not give the same orders. And I will demonstrate it later on. Let’s start with what we eat and how much food we really need.

Our food is supposed to provide us with all the substances necessary for functioning of our body. However, you should not believe everything we were taught at school: “eat everything and in big quantities and the body will automatically take only what is necessary”. Our body is the result of million years of evolution when little periods of abundance alternated with frequent periods of food shortages and fasting, so the body will take more or less whatever is fed. That means that when we eat, we have to give the necessary substances to our body, but don’t forget: they must be in adequate amounts, not too much and not too little.

In your previous article about bacteria you told that sugars are very harmful for us. But I am confused about the notion of sugar itself. We hear so much about sugars, glucose, fructose, simple sugars or simple carbohydrates, complex sugars or carbohydrates, soluble fibers, non-soluble fibers, starch, resistant starch etc… What is really harmful for us from this list?

I agree that “sugars” is a confusing term that should not be used, and that nomenclature is too complex for the non-specialist. All these substances you enumerated are the part of a very big family of carbohydrates. Inside of this family, to make it simple, you have glucose, glucose forming substances, fructose, soluble fibers that are transformed by bacteria in fats and glucose and insoluble fibers. And I propose to stop here.

I know that glucose is absolutely necessary for human life… Does the human body need to receive glucose from our food?

I like your question as you will immediately understand the underlying misunderstanding. Glucose is absolutely necessary for certain cells like red blood cells and brain cells. So yes, glucose in indispensable. But no, it is not necessary to eat it, as our body is able to synthetize all the glucose needed even if we do not eat glucose. It is the mechanism, known for more than 100 years, called neoglucogenesis which is the production of glucose from non-carbohydrate substances like glycerol of triglycerides, some amino-acids like alanine and glutamine, lactate, pyruvate etc…

Our body does not need external glucose that we are consuming in huge quantities by eating all sorts of grains, sugars etc. Lots of studies have shown that eating glucose can be, on the contrary, detrimental for health. And then we get surprised at developing type 2 diabetes or other important health problems… So, we have to beware of carbohydrates that can transform into glucose that we have been eating in recent centuries, and which are absolutely unnecessary for our body. When we eat pizza, pasta, bread, ice creams, sweets, cakes, we are just getting social pleasure, but harming our body which does not need these substances. In other words, our diet can be just fine with proteins in reasonable doses, with a lot of “good” fats and carbohydrates that do not transform into glucose, minerals and vitamins.

Fructose is toxic, so try to avoid it. There is no body cell able to use fructose. Fructose have a unique metabolism only in the liver and is transformed into fat transforming your liver into “foie gras”. Fructose has the ability to make you fat about 40 times more than glucose. Fructose found in fruits is the same molecule but is consumed in much lower quantities and with the fruit fibers, and this makes all the difference. So, eat fruits for their vitamins, but in low quantities and avoid artificial fructose.

Do you mean that this small amount of glucose generated by our body is enough for normal functioning of our cells?

Absolutely. It has been proved by many studies. You know that there are “essential nutrients”, where essential means that you must consume them as your body is unable to manufacture them. There are essential fats, essential amino acids, but there are no essentials carbohydrates and there is no illness known as glucose shortage.

You told that there are different carbs: transforming into glucose and not transforming. So let’s discuss this category of carbohydrates. What are they?

I will draw you the scheme to simplify (it is a very reduced representation of a much more complex relation):

So, as you have seen, not all carbohydrates contribute to health problems as obesity, for example, and diseases it provokes. For example, plants and fibers are also carbohydrates (“good” carbs), but only a fraction of them can be digested and transformed into glucose or short-chain fats. I am sure I can make you get fat by giving you the wrong carbohydrates in big amounts. It will happen not because of the number of calories but because some hormonal pathways will be dysregulated with substances themselves. I am convinced that obesity and other serious illnesses are of hormonal and metabolic origin, not genetic or caloric ones! Fibers (our “good” carbs) positively slow down digestion and absorption of nutrients, for example glucose, which is also important. They give volume (bulking effect) and fills you. Finally, some of them are transformed by your intestinal “good bacteria” in short chain fatty acids, important for your health.

Unfortunately, modern foods are processed, and fibers have mostly disappeared from our food, letting the carbohydrates being fully absorbed by our intestine, rising our insulin levels. And insulin is one of the most dangerous hormones especially in big quantities.

As we saw there are good and bad carbs. And what about fats? Are there really “good” fats?

Fats have been erroneously vilified by the medical community for 50 years. Contrary to popular belief many fats are indeed essentials for health.

For example, cholesterol (which is a type of fat) is vital. No cholesterol means no life! As you know there is a great debate actually to disprove de dangers of cholesterol. Other types of fats are also of primary importance. Fats help us to digest minerals and vitamins, fats are a major source of energy for our body cells, they are the components of cells membrane and of nerves sheaths, fats are important for inflammation and anti-inflammation processes as well as for blood clotting, etc… So, without fats, we are also dead. Like carbohydrates, there are many different types of fats.

Broadly speaking, these are the following types (other than cholesterol):

We need all fatty acids apart from trans fatty acids (which are unfortunately plentiful in our diet and in all types of frying and hydrogenated margarines). Some fatty acids are needed only in limited amounts. It’s like water: in small quantities it is essential, in large quantities it may drown you.

What products contain the necessary fatty acids?

Fish, green vegetables, certain vegetable oils (linen, colza), contain Omega 3.

Olive oil, avocados and most nuts have monounsaturated fatty acids. Milk, dairy products, i.e. cheese and butter, meat, contain saturated fatty acids.

Meat and the majority of vegetable oils contain also Omega 6.

Some words about proteins for our readers?

Proteins are absolutely essentials to life, but in moderate quantities, let’s say about 1 gram per kilo of weight per day (we speak about average people, not taking into account professional sportsmen or bodybuilders). My medical studies on biology and biochemistry (and lot of publications confirm this fact) convinced me that eating too many proteins can be as harmful as eating too many sugars, maybe more. For example, proteins activate metabolic pathways which inhibits repair mechanisms inside the cells and little people know that proteins also stimulate insulin.

You mentioned earlier that our metabolism had been formed by periods of abundance and shortage of food. We often talk about what should be eaten and what should not. Now we have identified what we need to eat for our body to function properly. But how important is the idea of fasting in our diet?

“How much to eat”, “what to eat” and “how often to eat” are the key points! In an ancient Egyptian manuscript found in a tomb it is written: “One-quarter of what you eat keeps you alive. The other three-quarters keeps your doctor alive.“

I am convinced that “how often to eat” plays the most important role in terms of evolution since, before supermarkets appeared, the periods of food shortage had prevailed over food abundance. Which means that all living creatures have developed taking this into account. There were periods of celebrations and periods of fasting. But there were no periods of restricting calories all the time. So, if we are to embrace this theory, we would have to explain from the biological point of view, how fasting periods can have a favourable effect, no matter how paradoxical it may sound for some people, on our health.

Fasting or calories restriction?

I am talking about fasting. Even if fasting and reducing calories have been shown to increase all animal lifespan, they are biologically quite different things. We are mainly all overfed now in western civilizations as we eat more in quantities and more often than our body needs. Calories restriction is better than eating like crazy, and calories restriction (depending how much) can extend your lifespan, but for losing weight it does not work on a long period and is certainly not helpful. So, we need fasting for some periods, as it has been in Nature.

Can you explain what happens when you fast?

Lots of metabolic adaptations are already known but we are just starting to understand the precise biochemistry of the underlying processes of fasting. What happens after your last meal?

After 3 hours, glucose, and amino acids coming from digested proteins, enter in the blood and rise up your insulin and other hormones. This insulin, among other jobs, put you in storage mode and makes the liver produce first glycogen (glucose energy storage in limited quantities), and then fat deposits (energy storage in unlimited quantities). There is no other way to store carbohydrates or proteins, so the body transform the extra load in fat! All turns into fat! Too many sugars turns into fat! Too many proteins turns into fat! But fat is not converted in fat! As fat does not stimulate insulin… This is fantastic!
After 12 hours without eating, insulin goes down and you have to transform your liver glycogen into glucose (these stocks are limited to some hours), and you will begin to transform your fat into energy.

After 36 hours of fasting, insulin is much more diminished, and you are finally taking almost all the energy from your fat mass. Your liver generates from fat ketonic bodies which are a fantastic fuel for your brain and other organs. Some studies say that it’s even better than glucose.

At the same time some other very important pathways are activated while you are fasting. In simple words, from birth to death we are constantly repairing and maintaining our body in its best working condition. But to do so, we need to renew constantly a certain amount of our constituent parts, including normal damaged proteins that have to be replaced by the new ones when the older go out.

However, the problem is that to replace the proteins that went out, you must have first a “thorough cleaning”: clear up the mess of unwanted stuff, discard or get rid of everything that does not work. This mechanism of replacement and getting rid of old stuff in our body lies at the heart of the 2016 Nobel Prize in Medicine and is called mechanism of autophagy (from Greek self-eating). The main idea of this mechanism is that when fasting, the body will start collecting fragments of cells and all broken and non-functioning substances and elements in order to make food from them. Autophagy helps to make a thorough cleaning in our body and to replace all broken things with the new and working ones.

But with our modern diet this autophagic mechanism does not work as it should, anymore. Our body is not just devoid of the capacity to “correctly repair” our cells by periodically making a thorough cleaning inside them. These non-functioning proteins will collect over other non-functioning proteins layer after layer. Studies show, and it is also my opinion, that this mechanism lies at the basis of many diseases as for example cancer, or Alzheimer’s disease when brain cells accumulate abnormal proteins.

Am I right to understand that cell mechanisms of autophagy and cell repair “turn on” when the body stops getting food?

Exactly! Our body cannot do 2 things simultaneously: it must choose between repair the old things or reproduce itself. The concept of 3 meals, and sometimes 6 meals a day in- cluding stupid snacks in between, turns out to be absolutely harmful since it gives wrong instructions to the body. By getting constant diet, our body switches into “reproduction” mode and turns off “the repair and cell maintenance” function.

And again, coming back to the origins of life when primary cells kept facing the choice: if I have food – I multiply, if I do not have food – I switch into the “standby and improve” mode when I “take stock” of everything, repair the damaged cells, improve myself to be in my peak shape at the moment when I get food and can multiply. Remember what I told you: Nature wants us not to live long, but to live long enough to pass our genes. So, in fasting mode, Nature improves the body (the soma) to allow a better and more efficient future transfer of genes. Hence, we can draw a conclusion from this: human body repeatedly needs both of these mechanisms: reproduction and restoration, reproduction and restoration, and so on. But with our lifestyle and diet as well as the constant supply of food, essentially rich in “bad” carbohydrates and “bad” fats with no fibers and lots of fructose, restoration and repair modes are practically always turned off and do not work, whereas the reproduction mode is set to high gear. And since the body does not have a chance to restore cells to their normal and healthy state before reproduction, this leads to a surge of various diseases.

All diets we hear about are reducing the amount of food consumed. And the main concept of many of them is to lower the number of calories. Is limiting the number of calories consumed the same thing as fasting and does it help to switch on the “cell repair” mechanism?

No, absolutely not!
First of all, I am convinced that the calories theory is wrong: it takes into account only the quantity of food eaten not the quality. Quantity of calories gives only the potential energy from food and not what the body will actually take from them. The way we prepare food as well as bacteria in our intestine are important factors that transform the energy we absorb. Calories counting does not consider many of these parameters.

Second, I think that what is important is what the calorie is composed of. Studies have clearly demonstrated that composition of calories (sugar, protein, fat, alcohol, etc…) is more important than quantities of calories in reducing illnesses and extending lifespan.

So, you have to go deeper into what lies at the basis of this cell choice between reproduction and restoration. In fact, there are some detectors or sensors in the body – they measure energy. These are mainly molecules that keep checking if the food (= energy) is enough. And these molecules send instructions to go into the autophagy (lack of food) or reproduction (enough food) mode. These indicators (about 5 known today) keep checking the presence of different substances. And as soon as you understand this, it becomes clear that it is not the number of calories that matters but rather the types of substances detected and their amount.

I give you another example. If you eat one avocado flesh of about 150 grams which has 22 grs of fats, 3 grs of proteins, no glucose and 12 grs of fibers, you will have about 230 kcal. There will be almost no effect on insulin and no bad effect on metabolism, no problem of weight gain, etc… It is a great food.

If you eat the same calories but from a chocolate cake for example, 230 kcal, you must eat only 60 grams, of which no fibers, 12 grs of fat, 3,5 grs of proteins but 25 grs of glucose. You will have the same calories, but your insulin and other hormones will get to the roof and will affect badly the expression of thousands of genes. In other words, calories matter but what composes calories is much more important, as proteins and sugars directly influence the switching mechanism of “restoration” into the “cell division”. Fats, that contain huge amounts of calories, have practically no influence on the detectors.

To summarize this, an optimal diet that helps the body to restore itself and come back to its normal, healthy, is to maximally cut the intake of carbohydrates transforming into glucose (“bad” carbs), to consume enough fats and, above all, “good” fats, and reasonable amounts of proteins because the excess of proteins and, primarily, of animal-derived proteins feeds harmful bacteria and blocks autophagy. But along with this qualitative aspect of food, it is very important that food intake has to alternate with periods of fasting.

Right. However, we have to explain the difference between eating less and not eating at all, and the difference between not eating for 1 hour and not eating for 24 hours. Which is not the same. Eating less is already good, but what is better is eating less of “bad” carbohydrates, and the best thing is fasting from time to time.

How long should this period of fasting last?

At least 12 hours. Ideally, 24 hours. That means eating once a day, at least once a week, but why not everyday if you feel ok… I would like to emphasize that we are talking about people with a good health status, not people with serious diseases. It is important to understand what causes gastritis. By the way there is no such treatment as eating more often as some doctors incomprehensibly prescribe). After 24 hours of fasting you will be able to reduce your insulin level by 70%, and your autophagy mechanism is activated!

If we are to eat once a day, should it be in the morning, in the afternoon or in the evening?

Ideally, it is better to eat in the morning as our body will secrete by 20– 25% more insulin in the evening, for the same meal. But from the social point of view, it is easier for us to eat in the evening, since we are always in a hurry in the morning, and towards the end of the day we want to be with our family and have dinner together. That’s why in real life it is easier to have dinner.

If you eat once every 24 hours, the body goes into the fasting mode and every meal is a surprise. And that means it is switched into restoration and repair mode most of the time. Whereas when you are eating regular meals with less food (calories), the body adapts by lowering its basic metabolism (this is absolutely fundamental!).

In other words, when you ate 2500 calories, your body waisted the same amount of energy and your weight is the same. Then you decide to lose weight and to reduce your consumption of food of 700 calories per day, for example, hoping that your body will waste the same number of 2500 calories and so you will “burn” your fat. But the problem is that your body adapts its metabolism and you will burn 700 calories less. So you find yourself in the same proportion as when you ate your 2500: you “burn” the same amount of what you ate. So you think why to limit myself and suffer? And you return to the initial situation and eat your 2500 calories per day hoping that your body will also return to waste the 2500 per day. But the problem is that your body basal metabolism will remain at 1800 calories (–700 calories). And the bad surprise (which is no more a surprise) is that you get fat. And at the same time cells will function with the repair mode switched off. Not good at all!

In other words, limiting the number of calories = lowering of basic metabolism = adaptation of the body = it does not work. Whereas, periodical fasting ≠ adaptation of the body ≠ lowering of basic metabolism = a mode that does work. To put it differently, as you understood, lowering the number of calories consumed gives a short-term effect, but then the situation deteriorates significantly.

Is periodical fasting good only for people who want to lose weight or for all people regardless their weight, since it allows, among other things, to restore the cells to the initial, healthy state, and losing weight is a pleasant side effect?

I want to reiterate, we are talking here about people without serious diseases. Studies confirm that thin person will not lose weight after periodical fasting but will most probably optimize metabolism and improve health. A lot of studies done on different kinds of animals from worms, to flies, to fishes and small mammals, dogs, primates and now humans, show a drastic improvement of longevity and good health. We can guess that people will likely live longer and have fewer diseases. But the most favourable effect of periodical fasting is for people with extra weight, most diseases of whom are caused by this extra weight.

And what do you think about fasting practiced in many religions?

I think this is no coincidence that all world religions have periods of fasting. Before religions appeared, people had realized that therapeutic fasting allowed to cure diseases and improve health etc. And later on, religions integrated the periods of fasting into their system.

What would you advise our readers who follow your rubric in terms of maintaining a good shape?

Tomorrow morning, we will be one day older, and there are no solutions to stop this process. But we can decrease the consequences of aging. My recommendation is, first of all, about nutrition reeducation. All diets have “nice” results on the short term, but you will regain weight. That is the fundamental problem. The quintessence of my approach is to reprogram the metabolism modifying how much, what, how often: don’t eat too much, don’t eat too many “bad” carbs, “bad” fats and proteins, don’t eat too often.

Once more, we exclude ill people, pregnant women and children from this recommendation. To all others, I would recommend having periods of 1 meal a day in normal amount (at least once a week up to every day if you feel well), consuming the less possible of glucose and carbohydrates transforming into glucose (non fibers), eating a moderate amount of proteins, having many “good” fats and all of this should come from foodstuffs that contain essential vitamins, trace elements and minerals. To give a practical example of a menu: eat red meat once a week or every 2 weeks, eat fish, seafood and other types of meat several times a week, eat any quantities of vegetables of all colours, since colours correspond to various vitamins, eat small quantities of fruit with little glucose content but with a lot of antioxidants and vitamins (e.g. wild berries, raspberry, blackcurrant, lingonberry etc.) for pleasure. The problem we are also facing now is the quality and the provenience of the food. Try to eat local and organic food as well as seasonal on.

Thanks a lot for your interview. And I suggest we should talk about diseases, inflammatory processes and their treatment by means of fasting in our next issue.