What science says about ketogenic diets and why they probably won't help you much "dry out".

Ketogenic diet

There are many different eating habits, many of which even have beautiful names, such as the South Beach Diet, Weight Watchers, Atkins Diet, HCG Diet, Volume Diet, Paleo Diet, IIFYM (literally “If ItFits Your Macros ”), the carbs-backloading, the ketogenic diet we’re going to talk about today.

One of the most commonly used diets is ketogen. Despite the fact that many people use it to burn fat, this diet is surrounded by a lot of misinformation.

Perhaps the most misunderstood aspect of a ketogenic diet is how it affects athletic performance and the ability to gain muscle and increase strength.

Ketogenic diet - from the word "ketosis"

Ketosis is a metabolic condition that occurs when the amount of carbohydrates in your diet is so low that your body simply needs to use fatty acids and body ketones to get energy. It seems that everything is simple, but let's understand this process to understand why our body enters a state of ketosis.

Our bodies need enough energy to function in the form of ATP.

ATP is a universal energy source for all biochemical processes in living systems.

To produce enough ATP and maintain vitality, a person needs an average of 1800 kcal per day (you can calculate your personal rate in the fitness calculator). At the same time, the average brain requires about 400 kcal per day and uses almost exclusively glucose as energy. This means that a personneeds to consume 100 g of glucose a day just to maintain normal brain function.

What has this got to do with ketosis? Using a ketogenic diet, we remove almost all carbohydrates from our diet, which means that we deprive the brain of glucose. But we still need our brains to function somehow. Fortunately, the liver stores glucose in the form of glycogen and can donate small amounts of it to our brains to function. Our liver can store an average of 100-120 grams of glucose. With a critical lack of carbohydrates for brain function, the liver allows us to function normally throughout the day. However, in the end, the liver's glucose reserves cannot be restored quickly, and carbohydrates are not only needed by the brain, so we have problems.

Our muscles also have a huge supply of glucose - they contain 400-500 grams of glucose in the form of glycogen.

However, glycogen stores are not primarily intended to feed the brain. Unfortunately, our muscles are unable to break down glycogen and put it in the blood to eventually feed our brains because the muscles lack an enzyme that breaks down glycogen (glucose-6-phosphate dehydrogenase).

In the absence of carbohydrates, ketone bodies begin to form in the liver, which enter our brain and other non-fat tissues through the bloodstream.

Let's take a quick look at the biochemistry of these processes. When you "burn fat", your body's fatty acid molecules are converted to acetyl-CoA, which in turn combines with oxaloacetate to start the Krebs cycle.

During ketosis, our liver consumes so much fat as energy that excess acetyl-CoA begins to produce ketone bodies (beta-hydroxybutyrate, acetoacetic acid and acetone).

Gradually,with a regular carbohydrate deficiency, the body enters a state where this process begins to take place constantly and the ketone body levels in the blood increase noticeably, then we can say that we are officially in a ketotic state.

What is a ketogenic diet and how is it different from a low carb diet

A low carb diet and a ketogenic diet are not the same thing.

What is a ketagen diet

Low fat diets use fats and carbohydrates for daily fats. Our bodies do not store ketone bodies in the blood, and our tissues do not use ketones for energy.

With a ketogenic diet, our body reaches a point where ketone bodies are produced in large quantities and used as fuel. During such diet-induced ketosis, beta-hydroxybutyrate levels can range from 0, 5 to 3. 0 mM / L. You can even purchase blood ketone test strips and measure yourself.

A low-carbohydrate diet limits the amount of carbohydrates in the diet (often just under 100 grams per day), but beta-hydroxybutyrate levels are below 0, 5, and 3. 0 mM / L.

How to eat on a ketogenic diet

As we discussed above, a ketogenic diet should be high in fat and low in carbohydrates.

In a traditional and strict ketogenic diet, 70-75% of your daily calories should come from fat and only 5% from carbohydrates. The amount of carbohydrates you can consume while staying in ketosis varies from person to person, but you can usually consume up to 12% of the calories from carbohydrates and stay in ketosis.

Protein intake is also very important. Most exercisers have come to think that they need to eat a lot of protein, which is probably one of the factors in unsuccessful ketogenic diets.

As we discussed earlier,protein can be broken down into glucose (during gluconeogenesis) at high doses, so you cannot get into ketosis.Basically, if you consume more than 1. 8 grams of protein per kg of body weight, that amount will be enough to get out of ketosis.

Ideally, in order to improve ketogenic status and maintain lean muscle mass, the diet should contain about 75% fat, 5% carbohydrates and 20% protein.

"Adaptation" phase in a ketogenic diet

If you read the literature on ketosis, you will see one general trend. There is the most pronounced phase of "adaptation", in which people feel a clouded mind, feel sluggish and lose energy. Basically, people feel very bad in the first weeks of a ketogenic diet. This is probably due to a significant lack of enzymes in our body that are needed to efficiently oxidize certain elements.

In order to survive, our bodies try to reuse other energy resources and learn to rely only on fat and ketone bodies. Usually after 4-6 weeks of adaptation to a ketogenic diet, all these symptoms disappear.

Ketosis and athletic performance: a review of scientific research

Let's look at some studies that may answer this question.

Study 1

The first study involved 12 people (7 men and 5 women aged 24 to 60 years) who were taking a ketogen diet on their own for an average of 38 days. The subjects underwent medium and intensive training, measuring their blood volume, body composition and maximum oxygen consumption.

The authors of the study themselves conclude: “Radical reduction of carbohydrates did not statistically significantly affect running performance, judging by the time subjects began to get tired and peak oxygen consumption, but body weight improved, participants lost 3. 4 kg of fat and gained 1. 3 kglean muscle mass. "

As a result, study participants lost weight but did not show significant changes in athletic performance. Subjects also reduced the body's ability to recover.

Study 2

Another study involved 8 men around the age of 30 with at least 5 years of training experience. The subjects sat on a 4-week mixed + ketogenic cross-style diet and performed extended stationary bicycle workouts of varying intensity.

The ketogenic diet also had a positive effect on body composition, as in the first study.

Interestingly, during the ketogenic diet, the values ​​of maximum oxygen consumption and oxygen consumption at the anaerobic threshold increased significantly. The increase in maximal oxygen consumption can be explained by a decrease in body weight. However, after a ketogenic diet,peak and anaerobic load were lower.

This means that the ketogenic diethas resulted in weight loss, but also a significant reduction in explosive strength and ability to train with high intensity. Do you want to be stronger and train more? Then don't think that a ketogenic diet is a good choice.

Study 3

The third study looked at how a 30-day ketogenic diet (4. 5% of carbohydrate calories) affected performance in the following exercises: leg hanging, floor suppression, depression, tightening, squatting and 30-second jump of parallel bars. Scientists also measure the body composition of the participants.

Here are the conclusions:

  1. A ketogenic diet caused a "spontaneous reduction in caloric intake" compared to a regular diet.
  2. Examination of ketogenic diet exercises showed no loss of performance, but no improvement in performance was found.

As in other studies, there were significant differences in body weight following a ketogenic diet: participants were able to lose weight. However, it should be borne in mind that the participants selected for this study were already quite "dry" (approximately 7% body fat).

It is also important to mention that in none of these tests was the glycolysis process considered as a source of energy, they were more tests of explosiveness, phosphagenic systems and muscle fatigue tests.

Study 4

In this study, 5 experienced cyclists performed a maximal oxygen consumption test and a time to exhaustion (TEE) test before and after a 4-week ketogenic diet.

Because this study is quite long, I want to focus only on the performance aspect and muscle glycogen levels. The TEE test showed a huge difference between the participants. One subject improved TEE scores by 84 minutes over 4 weeks, the other increased by 30 minutes, and two subjects decreased by 50 minutes, and one subject remained unchanged:

With respect to muscle glycogen stores, a muscle biopsy showed thatglycogen stores were almost half of their normal value after a ketogenic diet. This fact is already enough to say that good performance can be said goodbye.

Results of ketogenic diet studies

Let's look at what these 4 studies have in common:

  • Improved body composition.Each study allowed for a qualitative improvement in body composition. However, it is a controversial fact that this is a miraculous effect of a ketogenic diet, not a spontaneous calorie restriction. Because if you do any research on any type of diet and body composition, then any diet that restricts calories will improve your body composition.

    In the third study, subjects consumed an average of 10, 000 kcal less (minus 333 kcal per day! ) in 30 days than they did on a normal diet, and of course they lost weight.

    It is possible that a ketogenic diet may still offer additional benefits in terms of changes in body composition, but studies have not yet shown this.

    It should also be noted that there is no literature to support the idea that a ketogenic diet can help build muscle. It only helps to lose weight.

  • Reduced performance at high intensity loads. The first two studies showed the subjects' ability to decrease with high-intensity exercises. This is possible for two reasons: first, a decrease in intramuscular glycogen, and second, a decrease in liver glycogen stores during high-intensity training.
  • Reduction of intramuscular glycogen stores. Decreased sports performance during high-intensity training indicates reduced intramuscular glycogen levels, studies show. It can also negatively affect the recovery of athletes and the ability of muscles to grow.

Mistakes People Make in a Ketogenic Diet

Although there is no clear benefit over conventional calorie restriction, ketogenic diets can be a good way to lose weight. If you want to lose weight (possibly also with muscle mass), then maybe you should try it. Now let's look at the mistakes that people on a ketogenic diet often make so you don't avoid them.

  1. Lack of adequate adaptation phase

    Switching to a ketogenic diet can be very difficult for some people. Very often people stop the diet during the adaptation phase without completing it. The adjustment phase can last for several weeks, during which you feel weak, your consciousness blurs, and after 2-3 weeks your energy levels return to normal.

    If you want to try a ketogenic diet, give them plenty of time to adjust.

  2. Eating too much protein

    As we have learned, too much protein can prevent ketosis. People often replace low carbohydrates with high protein content in a ketogenic diet - this is a mistake.

  3. High Intensity Ketogen Diet

    For high-intensity anaerobic exercise, our body relies primarily on blood glucose stores, liver and muscle glycogen and gluconeogenesis.

    Because ketogenic diets reduce muscle glycogen levels, it is very difficult to train with a high load.

    Try an alternative carbohydrate diet instead of a ketogenic diet if you want to train hard.

  4. Ketogenic diets prevent muscle gain

    Ketogenic diets can help you lose weight but not gain muscle mass.

    CDs will not allow you to train with great intensity and gain lean muscle mass, so if these are the goals you are striving for in training, then it is better to abandon the idea of ​​practicing CDs.

Consumption of both protein and carbohydrates together produces a greater anabolic effect than consumption of these nutrients alone. By using a ketogenic diet, you reduce the amount of carbohydrates. Because both carbohydrates and proteins are needed for optimal muscle growth, one or both of these key nutrients are missing.

Conclusion: Ketogenic diets are neither optimal nor effective for building muscle and improving athletic performance. However, they can help you lose weight - just like any other calorie limit below your personal daily value.