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The ketogenic diet: eat fat to lose weight

 The ketogenic diet: eat fat to lose weight

With the ketogenic diet, you can lose weight quickly and permanently.

The ketogenic diet was originally developed to treat patients with epilepsy and consists of eating fat and abstaining from carbohydrates. It is said to lead to rapid and permanent weight loss. But what is the reality? Is it really effective? How is it done? Here are some explanations.

What is the ketogenic diet?

Overweight and obesity have reached unprecedented levels in our Western societies. The percentage of overweight people in the world and especially in Europe has led the WHO to declare the problem an epidemic. According to the latest WHO data, about one in two adults and one in three children are overweight or obese. Faced with this problem and the urgent need to reverse the trend, diets have quickly become increasingly popular.

Among the most well-known, the ketogenic diet is a name that pops up frequently. This special diet was originally designed to treat patients with epilepsy. However, it quickly became acclaimed by many specialists for its ability to make people lose weight quickly and permanently while improving their overall health and sports performance.

So, how does the ketogenic diet work, and what is its purpose? And most importantly, what are its limitations?

Ketosis as the basis of the ketogenic diet

The ketogenic diet, also known as the ketogenic diet, is based on a diet consisting primarily of fat (at least 70% of the diet) and foods that contain few or no carbohydrates. A ketogenic diet, diet consists of 70-80% fat, 15-20% protein, and 5-10% carbohydrates.

The keto diet relies on a special metabolic state of the body to achieve permanent weight loss. This is the metabolic state known as ketosis.

In the history of human evolution, the control of agriculture and animal husbandry is quite recent. In the past, periods of scarcity and abundance followed the rhythm of the seasons. To survive in difficult times, nature has endowed man with a formidable auxiliary generator that allows him to draw much of his energy from his own fat reserves.

Body fat thus becomes the body's primary fuel, replacing the glucose of carbohydrates. This is one of the main reasons for the significant weight loss seen at the end of the hard seasons.

From a metabolic point of view, ketosis is therefore a natural state of the human body in which its main source of energy changes. The ketogenic diet aims to force the body to use a different type of fuel. Instead of relying on sugar (glucose) from carbohydrates (grains, legumes, vegetables, and fruits), the body now gets its energy from ketone bodies. This is a type of fuel that the liver produces from stored fat.

keto diet?

In the world of nutrition, low-carb and high-protein diets are very popular. Paleo, South Beach, and Atkins diets fall into this category. It is often referred to as the ketogenic diet.

But there is a significant difference between this type of low-carb diet and a true ketogenic diet. In a ketogenic diet, the percentage of carbohydrates should not exceed 5-10%, whereas most low-carb diets simply limit the number of carbohydrates without setting a predetermined, low percentage.

The ketogenic diet

Improve athletic performance

Since this special diet encourages the body to burn its own fat to meet its needs, it is an excellent way to lose weight. Numerous studies on the subject have shown excellent short-term results.

There are many reasons why athletes want to lose weight: to improve their strength-to-weight ratio, to compete in a more favorable weight class, or, in the case of an activity such as bodybuilding, to burn as much body fat as possible for aesthetic reasons and to preserve muscle mass. In this sense, the ketogenic diet has the great advantage of allowing rapid weight loss without the well-known negative effects of other rapid weight loss methods.

But ketogenic diets are not just for weight loss. Many endurance athletes also follow these high-fat diets with very few carbohydrates to improve their performance. By forcing muscles to use fat instead of sugar, athletes obtain a much larger energy reserve, allowing them to avoid the "wall" that threatens when glycogen stores are depleted.

According to a study by Paoli Antonio et al, the ketogenic diet appears to have many advantages over many other types of energy-restricted diets. Even for a few days, it can lead to deficiencies or imbalances in essential nutrients (vitamins, minerals, essential fatty acids, and amino acids) that help control oxidative stress and inflammatory processes. A good ketogenic diet with sufficient protein (at least 1.3-1.5 g/kg body weight) is not an "extreme" diet, despite low carbohydrate levels (<20 g carbohydrates per day). Thus, it does not cause metabolic imbalances that may have irreversible consequences.

But it is not a panacea

Recent research suggests that athletes participating in short-term, high-intensity endurance sports may perform less well if they follow a ketogenic diet.

Researchers at Saint Louis University tested the anaerobic exercise performance of 16 men and women who followed either a ketogenic diet or a high-carbohydrate diet for four days.

Those who followed a ketogenic diet performed less well in anaerobic exercise tasks than those who consumed more carbohydrates. Depending on the exercise, their performance was between 4 and 15 percent lower than that of the high-carbohydrate diet group.

According to the study's author, Edward Weiss, associate professor of nutrition and dietetics at Saint Louis University, these results would therefore exclude athletes who engage in sports based on short-duration anaerobic activities. These include the speed activities of soccer and basketball, as well as short, intense activities such as the 100-meter dash, triple jump, etc., but some athletes report improved performance.

However, some athletes claim to have improved their performance on a carbohydrate-free diet. So ketogenic diets can be helpful in certain circumstances for people who know what they are doing and why they are doing it. If you're in this situation and you feel fine, there's no reason to change. For others, a low-carb diet rather than a ketogenic diet may be the answer.

Special Rules

In general, the ketogenic diet is a great way to lose weight fast. However, it requires a certain knowledge of how the human body works.

  • Firstly, it requires a significant reduction in carbohydrate intake. This means 20 to 50 grams of carbohydrates per day (on average, a large banana contains about 27 grams of carbohydrates).
  • It usually takes a few days to reach a state of ketosis.
  • Eating too much protein can interrupt ketosis.

Because of the large amount of fat that the keto diet requires, those who choose to follow it must eat fat at every meal. On a daily diet of 2,000 calories, this equates to about 165 grams of fat, 40 grams of carbohydrates, and 75 grams of protein. However, the exact ratio depends on individual needs.

All healthy unsaturated fats are allowed in the ketogenic diet. These include nuts (almonds, walnuts), seeds, avocado, tofu, olive oil, etc.

Although saturated fats are not prohibited, it is recommended that their consumption be limited because of their alleged link to cardiovascular disease.

In any case, too much of anything is bad. Therefore, it is important to try to properly alternate fat sources with healthy products. Some studies also point out the long-term stress this diet can cause to the liver. The liver is very active during the whole process.


The ketogenic diet is effective as a performance-enhancing diet for endurance athletes, and also as a special diet for weight loss and muscle maintenance.

However, for short-duration, high-intensity athletes, this diet appears to hurt performance. A low carbohydrate diet instead of a ketogenic diet may be a solution. Low carbohydrate diets may also be preferable in the long run because they are less restrictive and easier to maintain.


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