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

The ketogenic diet

There are many different diet plans, many of which even have beautiful names, such as the South Beach Diet, Weight Diet, Atkins Diet, HCG Diet, Volumetric Diet, Old Diet, IIFYM (literally "If it fits your macros" - "If it fits in the KBJU"), reverse carbohydrate loading (carbohydrate loading), the ketogenic diet, which will be discussed today.

One of the most common diets is the ketogenic one. 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 your athletic performance and ability to gain muscle and increase strength.

The 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 the body simply has to use fatty acids and the metabolism of ketone bodies for energy. Everything seems simple, but let's understand this process to understand why our body enters a state of ketosis.

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

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

A person needs an average of 1, 800 calories a day (you can calculate your personal value on a fitness calculator) to produce enough ATP and stay viable. At the same time, the middle brain requires about 400 kcal per day and uses almost only glucose as energy. This means that a personmust consume 100 g of glucose per day just to maintain normal brain function.

What has this got to do with ketosis? With a ketogenic diet, we remove almost all carbohydrates from our diet, which means that we deprive our brain of glucose. But we need our brain to function in some way. Fortunately, the liver stores glucose in the form of glycogen and can donate a small amount to our brain to keep it working. 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. In the end, however, glucose stores in the liver can not 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, our muscles cannot break down glycogen and put it into the bloodstream to eventually supply our brain, due to a lack of enzyme in the muscles that breaks down glycogen (glucose 6-phosphate dehydrogenase).

In the absence of carbohydrates, the liver begins to produce ketone bodies that are transported through the bloodstream to our brain and to 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 to acetyl-CoA, which in turn combines with oxalic acid to start the Krebs cycle.

During ketosis, our liver uses as much fat as energy so that excess acetyl-CoA begins to produce ketone bodies (beta-hydroxybutyric, acetic acid and acetone)

Gradually, with a regular carbohydrate deficit, the body reaches such a state that this process begins to appear constantly and the level of ketone bodies in the blood increases significantly, then we can say that we are officially in a state of ketosis.

What is a ketogenic diet and how does it differ from a "low carb" diet?

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

What is the ketogen diet

The low carb diet uses fats and carbohydrates for our daily energy needs. Our body does not store ketones in the blood and our tissues do not use ketones for energy.

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

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


How to eat on a ketogenic diet

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

In traditional and strict ketogenic diets, 70-75% of daily calories should be obtained 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 your calories from carbs and stay in ketosis.

Protein intake is also very important. Most practitioners have come to the conclusion that they need to consume large amounts of protein, perhaps this is one of the factors in a failed ketogenic diet.

As we discussed earlier,protein when consumed in high doses can be broken down into glucose (during gluconeogenesis) so you can not enter ketosis. Basically, if you consume more than 1. 8 grams of protein per kilogram of body weight, then this amount will be enough to get out of ketosis.

Ideally, in order to improve the ketogenic state and maintain muscle mass, your diet should be about 75% fat, 5% carbohydrates and 20% protein.

Phase "Adaptation" to a ketogenic diet

If you read the ketosis literature, you will see a general trend. There is the most discreet phase of "adaptation" in which people experience a blurred mind, feel sluggish and lose energy. Basically, people feel very bad in the first weeks of a ketogenic diet. This is probably due to the lack of essential enzymes in our body, which are essential for the oxidative efficiency of certain elements.

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

Ketosis and Athletic Performance: An Overview of Scientific Research

Let's take a look at some studies that could answer this question.

Study # 1

The first study included 12 people (7 men and 5 women, aged 24-60) who took a self-prescribed ketogenic diet for 38 days ataverage. People exercised moderately to vigorously, their blood count, body composition and maximum oxygen consumption were measured.

The study authors themselves conclude: "Radical carbohydrate depletion did not have a statistically significant effect on performance, judging by the time individuals began to fatigue and the level of maximum oxygen consumption, but the composition of body weight. "improved, participants lost 3. 4 kg of fat and gained 1. 3 kg of lean muscle mass. "

Thus, study participants lost weight but showed no noticeable change in athletic performance. Individuals also reduced the body's ability to recover.

Study # 2

Another study included 8 men about 30 years old with at least 5 years of educational experience. The subjects sat on a mixed + ketogenic diet for 4 weeks and did extensive static bike training at various intensities.

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

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

This means that theketogenic diet has resulted in weight loss, but also a significant reduction in explosive power and the ability to train at high intensity. Do you want to be stronger and train harder? Then do not assume that the ketogenic diet is a good choice for this.

Study # 3

The third study looked at how a 30-day ketogenic diet (4, 5% carbohydrate calories) affects performance in the following exercises: hanging increments, floor push-ups, parallel push-ups, pull-ups, squat jumping and 30-second jumps. The scientists also measured the body composition of the participants.

The following are the conclusions:

  1. The ketogenic diet caused a "spontaneous reduction in calorie intake" compared to the normal diet.
  2. No loss of performance was found with ketogenic diet, however, no improvement in performance was found.

As with other studies, there was a significant difference in body composition after the ketogenic diet: participants were able to lose weight. It should be borne in mind, however, that the participants selected for this study were already fairly dry (approximately 7% body fat).

It is also important to note that none of these tests looked at the glycolysis process as a source of energy, they were more tests that tested explosive strengths, phosphogenetics and muscle fatigue tests.

Study # 4

In this study, 5 experienced cyclists performed the maximal oxygen consumption test and the time to exhaustion test (TEE) before and after 4 weeks of gestation. diet.

Because this study is quite large, I want to focus only on the performance aspect and muscle glycogen levels. The TEE test showed a huge difference between the participants. One topic improved TEE scores by 84 minutes in 4 weeks, the second increased by 30 minutes, while two topics decreased by a total of 50 minutes and one topic remained unchanged:

Regarding muscle glycogen stores, a muscle biopsy showed thatglycogen stores after the ketogenic diet were almost half of their normal levels. This fact is already enough to argue that high performance can be said goodbye.

Research results for ketogenic diets

Let's take a look at the audience of these 4 studies:

  • Improved body composition.Each study resulted in a qualitative improvement in body composition. However, it is a controversial fact that this is the miracle effect of the ketogenic diet, despite the spontaneous calorie restriction. Because if you do any research on any diet and body composition, any calorie restricted diet will improve body composition.

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

    It is possible that the ketogenic diet may continue to provide additional benefits in terms of changing body composition, but research has not yet shown this.

    It should also be noted that there is no literature that supports the idea that a ketogenic diet can help build muscle. It only helps in weight loss.

  • Reduced performance at high loads. The first two studies showed a decrease in the ability of individuals 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. Decreased athletic performance during high-intensity training is an indication of decreased intramuscular glycogen levels, according to studies. It can also negatively affect the recovery of athletes who exercise and the ability of muscles to grow in size.

Mistakes People Make in Ketogenic Diets

Although there is no clear benefit to conventional calorie restriction, ketogenic diets can be a good weight loss tool. If you are looking to lose weight (perhaps through muscle mass), then maybe you should give it a try. Now let's look at the mistakes that people with a ketogenic diet often make, so that you do not make them.

  1. Lack of adequate adjustment phase

    Switching to a ketogenic diet can be very difficult for some people. Too often, people give up dieting during the adjustment phase without completing it. The adjustment phase can last several weeks, during which the weakness is felt, the consciousness is blurred, but after 2-3 weeks the energy levels return to normal.

    If you want to try a ketogenic diet, allow enough time to adjust.

  2. Eat too much protein

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

  3. Use of ketogenic diet in intense exercise

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

    As ketogenic diets reduce muscle glycogen levels, it is very difficult to train at high loads.

    Try an alternative carbohydrate diet instead of a ketogenic diet if you want to train at a high intensity.

  4. Ketogenic diets prevent muscle growth

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

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

Simultaneous consumption of proteins and carbohydrates produces a greater anabolic effect than consuming only these nutrients. In a ketogenic diet, you reduce carbohydrates. And because you need both carbohydrates and protein for optimal muscle growth, you are missing out on one or both of these essential nutrients.

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 restriction below your personal daily value.