What the scientific community thinks about ketogenic diets and why they may not help you "dry out".
There are many different ways of eating, many of which even have beautiful names, such as South Beach Diet, Weight Watchers Diet, Atkins Diet, HCG Diet, Volumetric Diet, Paleo Diet, IIFYM (literallyIt is "If it fits your macro"-"If it fits your KBJU"), reverse carbohydrate load (carbohydrate reload), ketogenic diet, will be discussed today.
One of the most widely used diets is the ketogenic diet. Although many people use it to burn fat, there is still a lot of misleading information about this eating habit.
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.
The ketogenic diet-from the term "ketosis"
Ketosis is a metabolic disease. When the carbohydrate content in the diet is so low that the body only needs to use the metabolism of fatty acids and ketone bodies for energy, ketosis occurs. Everything seems simple, but let us understand this process to understand why our body enters a state of ketosis.
Our body needs enough energy to function in the form of ATP.
ATP is the universal energy source for all biochemical processes in life systems.
A person needs to consume an average of 1, 800 calories per day (you can calculate your personal rate on the fitness calculator) to generate enough ATP and stay active. At the same time, the midbrain needs about 400 kcal per day and almost only uses glucose as energy. This means that a personneeds to consume 100 grams of glucose a day to maintain normal brain function.
What does this have to do with ketosis? Using a ketogenic diet, we can remove almost all carbohydrates from our diet, which means we are depriving the brain of glucose. But we do need our brains to work in a certain way. Fortunately, the liver stores glucose in the form of glycogen, which can donate a small amount of glucose to our brain to keep it functioning normally. Our liver can store 100-120 grams of glucose on average. Due to a severe lack of carbohydrates, the brain cannot function, and the liver allows us to function normally throughout the day. But in the end, the liver's glucose reserves cannot be replenished quickly, and not only the brain needs carbohydrates, which is why we have problems.
Our muscles are also huge glucose reservoirs-they contain 400-500 grams of glucose in the form of glycogen reservoirs.
However, glycogen reservoirs are not primarily used to feed the brain. Unfortunately, because muscles lack the enzyme that breaks down glycogen (glucose 6-phosphate dehydrogenase), our muscles cannot break down glycogen and put it in the blood to eventually feed our brain.
In the absence of carbohydrates, the liver begins to produce ketone bodies, which are transported through the blood to our brains and other tissues that do not use fat as energy.
Let us quickly introduce the biochemistry of these processes. When you "burn fat", the fatty acid molecules in your body will be converted into acetyl-CoA, and then combined with oxaloacetate to trigger the Krebs cycle.
In ketosis, our liver consumes so much fat and energy that excess acetyl-CoA begins to produce ketone bodies (β-hydroxybutyrate, acetoacetate and acetone).
gradually lacks carbohydrates, the human body reaches this state, and the process begins to happen continuously, 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 is it different from a "low carbohydrate" diet
A low-carb diet and a ketogenic diet are not the same thing.
A low-carbohydrate diet uses fat and carbohydrates to meet our daily energy needs. Our body does not store ketones in the blood, and our tissues do not use ketones for energy.
Using a ketogenic diet, our body has reached the point where a large amount of ketone bodies are produced and used as fuel. In ketosis caused by this diet, β-hydroxybutyrate levels can be between 0. 5 and 3. 0 mM / L. You can even buy blood ketone test paper and measure it yourself.
The low-carbohydrate diet limits the carbohydrate content of the diet (usually less than 100 grams per day), but the β-hydroxybutyrate level does not reach 0. 5 and 3. 0 mM /L.
How to eat through a ketogenic diet
As mentioned above, the ketogenic diet should be high in fat and low in carbohydrates.
In the traditional and strict ketogenic diet, 70-75% of daily calories should come from fat, while only 5% of calories come 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 carbohydrates and stay in ketosis.
Protein intake is also very important. Most exercisers have realized that they must consume a lot of protein, which may be one of the factors that make the ketogenic diet unsuccessful.
As we discussed before,protein is broken down into glucose when consumed in high doses (during gluconeogenesis), so you cannot enter ketosis.Basically, if you consume more than 1. 8 grams of protein per kilogram of body weight, that amount is enough to get rid of ketosis.
Ideally, in order to improve the ketogenic state and maintain lean muscle, your diet should contain approximately 75% fat, 5% carbohydrates and 20% protein.
The "adaptation" phase of the ketogenic diet
If you read the ketosis literature, you will see an overall trend. There is one of the most unique stages of "adaptation" in which people will feel blurred, sluggish and lose energy. Basically, during the first few weeks of the ketogenic diet, people feel very sad. This may be due to the lack of necessary enzymes in our body, and these enzymes cannot effectively oxidize certain elements.
To survive, our body tries to reconnect itself to use other energy sources, and learn to rely only on fat and ketone bodies. Usually, after 4-6 weeks of adapting to a ketogenic diet, all these symptoms will disappear.
Ketosis and Athletic Performance: A Review of Scientific Research
Let's look at some research that can answer this question.
Study #1The first study involved 12 people (average age 7 to 5 males, females 5 to 24 years old, and between 24 and 60 years old)They received a self-prescribed ketogenic diet, with an average diet time of 38 days. The subjects underwent moderate to vigorous training, and their blood counts, body composition and maximum oxygen consumption were measured.
The researchers themselves concluded: "According to the subjects’ time to fatigue and maximum oxygen consumption, statistically, the reduction of free radical carbohydrates did not have a significant effect on running performance, but the body weightAs a result, participants lost 3. 4 kg of fat and gained 1. 3 kg of lean muscle. "
Therefore, the study participants lost weight, but there was no significant change in athletic performance. Moreover, the subjects reduced the body's ability to recover.
Study #2Another study involved 8 men about 30 years old with at least 5 years of training experience. The subjects received a 4-week mixed + ketogenic crossover diet and performed stationary bicycle exercises at different intensities.
The ketogenic diet also has a positive effect on body weight composition, as in the first study.
Interestingly, the relative value of maximum oxygen consumption and anaerobic threshold oxygen consumption in the ketogenic diet increased significantly. The increase in maximum oxygen consumption can be explained by the decrease in body weight. However, the maximum workload ofafter the ketogenic diet and the workload under the anaerobic threshold are lower.
, which meansthe ketogenic diet will cause weight loss, but the explosive strength and high-intensity training ability will also be significantly reduced. Do you want to be stronger and train harder? Then don't think that the ketogenic diet is a good choice.
Study #3The third study examined how a 30-day ketogenic diet (4. 5% calories in carbohydrates) affects performance during the following exercises: Hanging leg raises, push-ups, parallel bar push-ups, pull-ups, squat jumps and 30-second jumps. The scientists also measured the body composition of the participants.
Here is the conclusion:
Compared with the regular diet, the ketogenic diet causes a "spontaneous reduction in calorie intake".Like other studies, there was a significant difference in body weight composition after the ketogenic diet: participants were able to lose weight. However, it should be remembered that the participants in this study are already quite dry (about 7% body fat).
It is worth mentioning that none of these tests regard the glycolysis process as an energy source. They are more about testing the explosive strength, the phosphorus system and muscle fatigue tests.
Study #4In this study, 5 experienced cyclists performed maximum oxygen consumption before and after 4 weeks of ketogenic dietTesting and time to exhaustion (TEE) testing.
Since this is a rather long study, I only want to focus on performance and muscle glycogen levels. The TEE test showed a huge difference between participants. One subject increased the TEE score by 84 minutes in 4 weeks, the second subject increased by 30 minutes, and the second subject decreased by a total of 50 minutes, while one subject remained unchangedChange:
Regarding muscle glycogen storage, muscle biopsy revealed thatglycogen storage is almost half of normalafter a ketogenic diet. This fact is enough to show that high performance can say goodbye.
Research results of the ketogenic diet
Let's take a look at the common points of these 4 studies:
Improved body composition.Each study resulted in a qualitative improvement in body composition. However, this is a controversial fact. It is the magical effect of the ketogenic diet, not the spontaneous restriction of calories. Because if you study any kind of diet and body composition, then any calorie-restricted diet will improve body composition.
In the third study, the subjects lost an average of 10, 000 kcal (333 kcal per day! ) in 30 days compared to a normal diet, and of course they lost weight.
The ketogenic diet may still provide other benefits in terms of body composition changes, but research has not yet shown this.
It should also be said that there is no literature to support the idea that a ketogenic diet can help build muscle. It will only help lose weight.
- Performance degradation under high-intensity loads. The first two studies have shown that subjects’ ability to perform high-intensity exercise has decreased. There may be two reasons for this: firstly, during high-intensity training, intramuscular glycogen is reduced, and secondly, it is reduced in liver glycogen storage.
- Reduce intramuscular glycogen storage. Studies have shown that decreased performance during high-intensity training is a sign of decreased intramuscular glycogen levels. It may also negatively affect the recovery and muscle growth of athletes.
People make mistakes on the ketogenic diet
Although there are no obvious benefits over regular calorie restriction, a ketogenic diet can be a great 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 take a look at the mistakes that people on the ketogenic diet often make, so you don’t make these mistakes.
Lack of adequate adaptation phase
For some people, switching to a ketogenic diet can be very difficult. People often withdraw from the diet during the adaptation phase without completing the diet. The adaptation phase can last for several weeks, during which time weakness and confusion are felt, but after 2-3 weeks, the energy level returns to normal.
If you want to try the ketogenic diet, please allow enough time to adapt.
Eat too much protein
As we already know, too much protein can prevent ketosis. People often substitute high protein for low carbohydrates in a ketogenic diet-this is a mistake.
Use a ketogenic diet during high-intensity exercise
For high-intensity anaerobic exercise, our body mainly depends on blood sugar storage, liver and muscle glycogen, and gluconeogenesis.
Because the ketogenic diet reduces muscle glycogen levels, high-load training is very difficult.
If you want high-intensity training, try a carbohydrate replacement diet instead of a ketogenic diet.
A ketogenic diet can prevent muscle growth
A ketogenic diet can help you lose weight, but it will not increase muscle mass.
CD will prevent you from high-intensity training and gain lean muscle, so if these are your goals in training, then it is best to give up the idea of practicing CD.
Compared with consuming these nutrients alone, the simultaneous intake of protein and carbohydrates will produce greater anabolic effects. In the ketogenic diet, you reduce carbohydrates. Moreover, because both carbohydrates and protein are needed for optimal muscle growth, you lack one or two of these key nutrients.
Bottom line: The ketogenic diet is neither the best way to build muscle mass and improve athletic performance, nor is it effective. However, they can help you lose weight-just like any other calorie intake limit is lower than your personal daily intake.