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

Ketogenic diet

There are many different eating patterns, most of which have good names, such as the South coast diet, weight watchers, Atkins diet, HCG diet, volumetric diet. , paleo diet, IIFYM (literally "If It Fits Your Macros" - "If It Fits Your KBJU"), reverse carbohydrate loading (carb-restore), the ketogenic diet that will be discussed today.

One of the most widely used diets is ketogenic. Although many people use it to burn fat, this diet is surrounded by a lot of misinformation.

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

Ketogenic diet - from the word "ketosis"

Ketosis is a metabolic state that occurs when the amount of carbohydrates in your diet is too low, when the body has to use only fatty acids and the metabolism of ketone bodies for energy. It seems that everything is simple, but let's understand this process to understand why our bodies enter a state of ketosis.

Our body needs sufficient energy in the form of ATP to function.

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

To produce enough ATP and maintain its viability, a person needs an average of 1, 800 calories per day (you can calculate your personal rate in a fitness calculator). At the same time, the midbrain requires about 400 kcal per day and uses almost exclusively glucose as energy. This means thata person only needs to consume 100g of glucose per day to maintain normal brain function.

What does this have to do with ketosis? With a ketogenic diet, we remove almost all carbohydrates from our diet, which means we are depriving our brains of glucose. But we need our brains to work somehow. Fortunately, the liver stores glucose in the form of glycogen and can donate a small amount to our brains to keep it working. Our liver can store an average of 100-120 grams of glucose. With a lack of carbohydrates critical to the functioning of the brain, the liver allows us to function normally throughout the day. However, after all, the liver's glucose reserves cannot be replenished quickly and carbohydrates are not only needed by the brain, so we have problems.

Our muscles are also a huge storehouse of glucose - they contain 400-500 grams of glucose in the form of glycogen stores.

However, glycogen stores are not primarily designed to feed the brain. Unfortunately, due to a lack of an enzyme that breaks down glycogen (glucose-6-phosphate dehydrogenase) in our muscles, our muscles cannot break down glycogen and eventually put it into the bloodstream to feed our brains.

In the absence of carbohydrates, the liver begins to produce ketone bodies, which are carried through the bloodstream to our brain and other tissues that do not use fat for energy.

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

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

Graduallywith regular carbohydrate deficiency, the body becomes such that this process begins to occur continuously and the level of ketone bodies in the blood increases visibly, then we can officially say that we are in ketosis.

What is a ketogenic diet and how is it different from a "low carbohydrate" diet

Low-carb diet and ketogenic diet are not the same thing.

What is the Ketagen diet

Low carbohydrate diet uses fat and carbohydrates for our daily energy needs. Our bodies do not store ketone bodies in the blood and our tissues do not use ketones for energy.

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

The low-carb diet limits the amount of carbohydrates in the diet (usually just under 100 grams per day), but beta-hydroxybutyrate levels do not reach 0, 5, and 3. 0 mM / L.

How to eat on a ketogenic diet

As we discussed above, the ketogenic diet should be high in fat and low in carbs.

In traditional and solid ketogenic diets, 70-75% of daily calories should be taken 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 12% of your calories from carbohydrates and stay in ketosis.

Protein intake is also very important. Most trainees have borne in mind that they need to consume large amounts of protein, perhaps this is one of the factors of failed ketogenic diets.

As we discussed earlier, proteincan be broken down into glucose (during gluconeogenesis) when consumed in high doses and therefore you cannot enter ketosis.Basically, if you consume more than 1. 8 grams of protein per 1 kg of body weight, that amount will be enough to get rid of ketosis.

Ideally, your diet should be about 75% fat, 5% carbohydrate, and 20% protein to improve ketogenic status and maintain lean muscle mass.

"Adaptation" phase in ketogenic diet

If you read the

ketosis literature, you will see a general trend. There is the most obvious "adaptation" phase in which people experience a blurry mind, feel sluggish and lose energy. Basically, people feel really bad during the first weeks of the ketogenic diet. This is probably due to the lack of essential enzymes in our body that are needed to efficiently oxidize certain elements.

In order to survive, our body tries to learn to use other energy sources and to rely solely on fat and ketone bodies. Generally, all these symptoms disappear after 4-6 weeks of adhering to the ketogenic diet.

Ketosis and Athletic Performance: A Review of Scientific Research

Let's take a look at a few studies that might answer this question.

1st Study

The first study involved 12 subjects (7 men and 5 women aged 24-60 years) who followed a self-prescribed ketogenic diet for an average of 38 days. Subjects underwent moderate to intensive training, blood counts, body composition and maximum oxygen consumption were measured.

The authors of the study concluded: “Radical carbohydrate reduction did not show a statistically significant effect on running performance when looking at when subjects started fatigue and their maximum oxygen consumption level, but body mass composition improved, participants lost 3. 4 kg of fat 1. He gained 3 kg of lean muscle mass. "

Therefore, study participants lost weight but did not show any noticeable change in athletic performance. Also, the subjects reduced the body's ability to heal.

Study 2

Another study involved 8 men of about 30 years old with at least 5 years of educational experience. Subjects sat on a 4-week mixed + ketogenic crossover style diet and did long-term stationary cycling workouts of varying intensity.

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

Interestingly, the relative values ​​of oxygen consumption at the maximum oxygen consumption and anaerobic threshold increased significantly in the ketogenic diet. The increase in maximum oxygen consumption can be explained by the decrease in body weight. However,the maximum workload and workload at the anaerobic thresholdwere lower after the ketogenic diet.

This means that theketogenic diet causes weight loss but also causes a significant decrease in bursting power and the ability to exercise at high intensity. Do you want to be stronger and work harder? Then don't think the ketogenic diet is a good choice for this.

3rd Study

The third study examined how a 30-day ketogenic diet (4. 5% calories from carbohydrates) affects performance in the following exercises: hanging leg lifts, push-ups on the floor, parallel stick push-ups, pull-ups, squat jumping and 30-second jumps. The scientists also measured the participants' body composition.

Results are:

  1. Ketogenic diet caused "spontaneous reduction in calorie intake" compared to the normal diet.
  2. No performance loss was found with the ketogenic diet exercise tested, but no performance enhancement was found.

As with other studies, there was a noticeable difference in body weight composition after the ketogenic diet: participants were able to lose weight. However, it should be noted that the participants selected for this study were already fairly dry (about 7% body fat).

It is also important to note that none of these tests looked at the glycolysis process as an energy source, there are more tests testing explosive strength, phosphagenic system and muscle fatigue.

Study 4

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

Since this study is quite long, I want to focus only on the performance aspect and muscle glycogen levels. The TEE test showed a big difference between the participants. One subject increased their TEE scores by 84 minutes in 4 weeks, the second increased by 30 minutes, two subjects dropped by 50 minutes, and one subject remained unchanged:

Regarding muscle glycogen stores, a muscle biopsy showed that glycogen storesare almost half their normal values ​​after ketogenic diet. This fact is enough to claim that you can say goodbye to high performance anyway.

Research results on ketogenic diets

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

  • Improved body composition.Each study resulted in a qualitative improvement in body composition. However, it is a controversial fact that this is the miraculous effect of the ketogenic diet rather than calorie restriction per se. Because if you do any research on any diet and body composition, any diet that restricts calories will improve body composition.

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

    The ketogenic diet is likely to still offer additional benefits in terms of changes in body composition, but research has not yet shown this.

    It should also be said that there is no literature supporting the idea that the ketogenic diet can help build muscle. It just helps to lose weight.

  • Poor performance at high density loads. The first two studies showed a decrease in the subjects' ability to exercise at high intensity. 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. Studies have shown that decreased athletic performance during high-intensity training decreases intramuscular glycogen levels. It can also negatively affect the recovery of athletes who exercise and the ability of muscles to grow in size.

Mistakes people make on ketogenic diets

While there is no clear benefit over traditional calorie restriction, ketogenic diets can be a good weight loss tool. If you want to lose weight (perhaps through muscle mass) then maybe you should try it out. Now let's look at the common mistakes people on ketogenic diets make to avoid you.

  1. Not enough adaptation stage

    Switching to a ketogenic diet can be very difficult for some people. Often times, people leave their diet uncompleted during the adaptation phase. The adaptation phase can take several weeks, when weakness is felt, consciousness becomes cloudy, but after 2-3 weeks energy levels return to normal.

    If you want to try a ketogenic diet, take plenty of time to adapt.

  2. Eating too much protein

    As we learned earlier, too much protein can prevent ketosis. People often replace low carbohydrates with high protein on the ketogenic diet - it's a mistake.

  3. Using a ketogenic diet in high intensity activity

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

    It is very difficult to exercise with high loads, as keto diets lower muscle glycogen levels.

    If you want to exercise at high intensity, try a carbohydrate alternative diet instead of the ketogenic diet.

  4. Ketogenic diets prevent muscle gain

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


    CD will prevent you from exercising at high intensity and gaining lean muscle mass, so if these are the goals you are pursuing in your training, it is better to forego the idea of ​​applying a CD.

Consuming both protein and carbohydrates together produces a greater anabolic effect than consuming these foods alone. You reduce carbohydrates on the ketogenic diet. And since you need both carbohydrates and protein for optimal muscle growth, you're missing one or both of these essential nutrients.

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