Le régime cétogène est-il adapté aux sportifs ? | Holyfat

Is the ketogenic diet suitable for athletes?

Does carbohydrating fat optimize performance? How can you go without sugar?

Holyfat explains the ketogenic diet and helps you understand how fat can become the fuel of choice during workouts/athletic competitions.

What is the ketogenic diet?

The ketogenic diet has been used for more than 90 years, particularly for therapeutic purposes (for example, in the case of epilepsy, diabetes or cancer). It is based on a simple principle: reduce carbohydrate intake as much as possible so that fat takes the lion's share.

Today, the ANSES (National Agency for Food, Environmental and Occupational Health Safety) recommends the following distribution for the daily diet of a healthy adult

  • Protein: 10 to 20% of total energy intake (TEA)

  • Fat: 35 to 40% of TEE

  • Carbohydrates: in addition to the ration, i.e. 40 to 55% of the TEE, with less than 10% of simple sugars (excluding lactose) and sweet products.

For an athlete, these needs may vary, depending on the sport practiced, its frequency/intensity, as well as specific individual needs, but it is often lipids that are reduced in favor of carbohydrates.

In the ketogenic diet, the distribution is totally different! No more sugars, hello fat. In order to enter a state of ketosis (see explanation below), it is necessary to redistribute the cards to consume only 5% of carbohydrates (i.e. max 20g/day, which are still essential for certain so-called strict glucose-dependent cells, such as red blood cells). There is another similar diet but a little less strict in terms of carbohydrate distribution: the LCHF, "low-carb, high fat". This is the same principle, except that the daily carbohydrate intake is around 20 to 50g.

Why "ketogenic"?

After a night's sleep, blood sugar levels are low. Several metabolic pathways come into play to ensure the proper functioning of the human body.

Ketogenesis is one of them, it allows the production of ketone bodies in the liver from the lipids stored in our adipose tissue. These ketone bodies are used by muscle cells, organs and neurons. They are the preferred source of energy for the renal cortex and the heart and can provide, in periods of prolonged fasting, up to 75% of the energy consumed by the brain (the glucose reserves in the form of glycogen in the liver or the muscles provide the remaining 25%).

The ketogenic diet therefore takes its name from this metabolic pathway, which allows the body to use lipids as an energy source instead of carbohydrates.

What is the point of following this diet?

Let's do a little comparison between what happens to a person who eats "normally" and a person who follows a ketogenic diet.

To begin with, once the glycogen stocks are depleted, ketone bodies should take over. But it's not that simple.

In reality, we have to go back to what happens in the human body. The main energy substrate is carbohydrates, so in a so-called normal diet (with 40 to 55% carbohydrates in your diet).

Situation A : Normal diet, food balance recommended by ANSES

After the meal, blood sugar levels will rise. The more carbohydrate-rich foods you eat , the higher your blood sugar will be. Add to this the capacity of a food to raise blood sugar levels, which is called the glycemic index (GI). A meal rich in high GI foods and low in fiber, fat and protein (for example: fruit juice, baguette, honey, or before a race: sports nutrition products such as gel), will raise blood sugar very quickly. But it will also go down quickly, and it is at this moment that we can encounter certain problems (sweating, palpitations, dizziness, nausea, trembling, intense fatigue...). This is called reactive hypoglycemia.

It is even more valid in the context of sport because the energy expenditure is increased tenfold, the effort provided being much more intense for our body. This is why when you start to consume gel, fruit paste or an effort drink, it is necessary to take it every 45 minutes, otherwise beware of the slackness. But when you run or cycle for hours and regularly consume sugar products this can lead to disgust and intestinal problems.

After a meal, the blood will be full of glucose. The pancreas will release insulin, the hormone responsible for regulating this sugar level, to allow glucose to enter the cells that need fuel. The excess will be synthesized into glycogen in the liver and muscles (via glycogenogenesis) to create glucose stores, the rest will be transformed into triglycerides and stored in fat cells via lipogenesis (literally, the manufacture of fat). Namely, as long as the cells have sugar, it will not draw from the fat reserves to continue the effort ...

These famous fat reserves will be used during fasting in a resting situation. On the other hand, during the effort, the body does not have time to adapt, it needs energy immediately to maintain the pace: it is therefore mandatory to refuel frequently to continue the physical effort.

Situation B: Ketogenic diet, fat from fat

During a ketogenic diet, the consumption of lipids will be the majority at 80%, proteins and a very small amount of carbohydrates, the vital minimum. Namely, carbohydrates, unlike proteins or fats, are the only non-essential nutrient in large quantities since our body is able to synthesize them (they are nevertheless essential for our red blood cells or our neurons and should not be totally eliminated, of course).

The body will therefore be deprived of carbohydrates over a long period of time, not just for a few hours. It will then gradually enter into what is called a state of ketosis. Ketosis is when the body switches from glucose to ketone bodies. The few grams of sugar left in the day are therefore destined for our glucose-dependent cells, which cannot feed on ketones. An individual who begins the ketogenic diet, or LCHF, will take about 2 to 3 weeks to enter this state of ketosis. He will also go through several phases that are not necessarily pleasant at first, while the body gets used to and is weaned from sugar: fatigue, nervousness, nausea, ...

Once this period is over, the transition will be complete and the individual, known as "keto adapted", will naturally consume fat as fuel rather than carbohydrates! They will then be much more easily satisfied and in good shape since they will no longer be subject to variations in blood sugar levels (and therefore no more feeling hungry at 11am, craving chocolate in front of the TV at 4pm). Often, he will lose weight, since he will draw on his fat reserves to provide energy to his muscles and organs.

Note that there is a new trend that is emerging, we talk about "Metabolic Flexibility". We'll talk about this in a future article, let's just say that it's the next step, once you're fully keto-adapted and you still want to add back some carbohydrates.

The ketogenic diet and sport

So is it worth looking at fat only in the context of sport?

Yes, it is. To start, let's compare the composition of a sweet gel and a good fat snack.

In the gel, lambda brand, there is an average of 70% carbohydrates, often in the form of glucose syrup and maltodextrin, less than 0.5% fat and less than 1% protein. The rest is water, salt and a few milligrams of vitamins and fatty acids. For a pouch of about 30g, you have the equivalent of 90kcal in energy.

At Holyfat, we work on the basis of the ketogenic diet. Our products contain 70% of lipids (and good ones: walnuts, almonds, macadamia, MCT oil), less than 3% of carbohydrates (naturally included in oilseeds) and 20% of proteins. A

pouch of 40g

provides you with an average of 280kcal, that is to say three times more than a gel for the same quantity, and without causing any variation of glycemia. A good dose of energy, constant, which enables you to hold a long time without hunger and without fall of energy.

Indeed, even if you are not keto adapted, consuming fat before and during the sports outing instead of sugar will prevent any variation in blood sugar levels and will allow you to go the distance and last. However, we advise you to keep a source of carbohydrates on hand and to consume it in the last hour of the effort to give a last little boost before the finish line (and to recharge glycogen reserves). Of course, all these dietary tests should be done during training, not on the day of a competition, as everyone has their own reactions and habits.

In a nutshell good fat is life !

So don't hesitate to consume it, on a daily basis if you want to start a ketogenic diet or during an effort, especially a long one!

However, in certain physiological or pathological conditions (pregnancy, breastfeeding, diabetes under insulin,...), the ketogenic diet is not recommended. If you wish to try it, it is necessary to contact a doctor or a dietician to accompany and guide you in this dietary transition.

>> Don't hesitate to consult our other articles, in particular "How to avoid fatigue during exercise, especially during an endurance sport", "What is a hypoglycemic crisis", as well as our zooms on almonds orMCT oil... With the added bonus of a few tips and advice for your preparation and your sports outings (or your busy days).

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