What science says about ketogenic diets and why they probably do not help you "dry out" much.
There are many different eating patterns, many of which even have beautiful names, such as the South Beach diet, weight watchers, Atkins diet, HCG diet, volumetric diet, paleo diet, IIFYM (literally “Ifit fits your macros ”-“ if it fits into your KBJU ”), reverse carbohydrate loading (carbohydrate backloading), the ketogenic diet that will be discussed today.
One of the most commonly used diets is ketogenic. 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 the ketogenic diet is how it affects athletic performance and your ability to gain muscle mass 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. It seems like everything is simple, but let's understand this process to understand why our body goes into a state of ketosis.
In order to function, our body needs a sufficient amount of energy in the form of ATP.
ATP is a universal energy source for all biochemical processes in living systems.
A person needs an average of 1, 800 calories a day (you can calculate your personal rate on a fitness calculator) to produce enough ATP and stay viable. At the same time, the midbrain requires approx. 400 kcal a day and uses almost only glucose as energy. This means that a personneeds to consume 100 g of glucose a day just 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 that we deprive our brain of glucose. But we need our brain to work somehow. Fortunately, the liver stores glucose in the form of glycogen and can donate a small amount of it to our brain to keep it going. Our liver can store an average of 100-120 grams of glucose. With a critical lack of carbohydrates that the brain can function on, the liver allows us to function normally throughout the day. Ultimately, however, liver glucose reserves cannot be replenished quickly, and carbohydrates are not only needed in the brain, which is why we have problems.
Our muscles are also a large store 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 in the bloodstream to eventually feed our brain due to the lack of an enzyme in muscle that breaks down glycogen (glucose-6-phosphate dehydrogenase).
In the absence of carbohydrates, the liver begins to produce ketone bodies that are carried through the bloodstream to our brain and other tissues that do not use fat for energy.
Let's quickly review the biochemistry of these processes. When you "burn fat", the fatty acid molecules in your body are converted to acetyl-CoA, which in turn is combined with oxaloacetate to start the Cancer cycle.
During ketosis, our liver uses so much fat as energy that excess acetyl-CoA begins to produce ketone bodies (beta-hydroxybutyrate, acetic acid and acetone).
Gradually,with a regular deficit of carbohydrates, when the body reaches such a state that this process begins to occur constantly, and the level of ketone bodies in the blood increases markedly, then we can say that we are officially in a stateof ketosis.
What is a ketogenic diet and how does it differ from a "low carb" diet
A low carb diet and a ketogenic diet are not the same thing.
The low-carb diet uses fats and carbohydrates for our daily energy needs. Our body does not store ketone bodies 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. Under 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.
A low carbohydrate diet limits the amount of carbohydrates in the diet (often just under 100 grams per day), but the levels of beta-hydroxybutyrate do not reach 0, 5 and 3. 0 mM / L.
How to Eat a Ketogenic Diet
As we discussed above, a ketogenic diet should be high in fat and low in carbohydrates.
On traditional and strict ketogenic diets, 70-75% of the 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 your calories from carbohydrates and stay in ketosis.
Protein intake is also very important. Most interns have got it in their head that they need to consume large amounts of protein, perhaps this is one of the factors in failed ketogenic diets.
As we discussed earlier,protein, when ingested in high doses, can be broken down into glucose (during gluconeogenesis) and thus you cannot enter ketosis.Basically, if you use more than 1. 8 grams of protein per serving. 1 kg body weight, this amount will be enough to get out of ketosis.
Ideally, your diet should be 75% fat, 5% carbohydrates and 20% protein to improve ketogenic status and maintain lean muscle mass.
"Adaptation" phase of a ketogenic diet
If you read the ketosis literature, you will see a general trend. There is the most characteristic "adaptation phase", where people experience a cloudy mind, feel sluggish and lose energy. Basically, people feel really bad in the first weeks of a ketogenic diet. This is probably due to the lack of essential enzymes in our body, which are necessary to effectively oxidize certain elements.
To survive, our body tries to reorient itself to use other energy resources and learn to rely only on fats and ketone bodies. Usually, all these symptoms go away after 4-6 weeks of adjusting to a ketogenic diet.
Ketosis and Athletic Performance: A Review of Scientific Research
Let's look at a few surveys that can answer this question.
Study No. 1The first study involved 12 people (7 men and 5 women aged 24-60) who on average had a self-prescribed ketogenic diet for approx. . 38 days. Subjects performed moderate to intense exercise, their blood count, body composition, and maximum oxygen consumption were measured.
The study authors themselves conclude: “Radical reduction of carbohydrates did not affect ongoing performance statistically significantly, judging by the time the subjects began to fatigue and the level of maximum oxygen consumption, but body weight composition improved, participants lost 1, 4 kg lost 1, 4, 3 kg lean muscle mass. "
Study participants thus lost weight but showed no noticeable change in athletic performance. In addition, the subjects reduced the body's ability to recover.
Study # 2Another study involved 8 men in their 30s with at least 5 years of training experience. Subjects sat on a 4-week cross-style mixed + ketogenic diet and performed prolonged exercise on a stationary bike of varying intensity.
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 oxygen consumption at the anaerobic threshold increased significantly on the ketogenic diet. The increase in maximum oxygen consumption can be explained by a decrease in body weight. However,peak workload and workload at anaerobic threshold were lower after the ketogenic diet.
This means that theketogenic diet resulted in weight loss but also a significant decrease in explosive strength 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 No. 3The third study examined how a 30-day ketogenic diet (4. 5% calories from carbohydrates) affects performance in the following exercises: raisingleg heights, push-ups in the floor, push-ups with parallel bar, pull-ups, squat jumping and 30th jump. The researchers also measured the participants' body composition.
Here are the conclusions:
- The ketogenic diet caused a "spontaneous reduction in calorie intake" compared to the regular diet.
- No performance loss was found with the ketogenic diet exercise tested, but no performance improvement 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 remembered that the participants selected for this study were already quite “dry” (approximately 7% body fat).
It is also important to mention that none of these tests looked at the glycolysis process as an energy source, they were several tests that tested explosive strength, the phosphogenic system and muscle fatigue test.
Study No. 4In this study, 5 experienced cyclists performed the maximum oxygen consumption test and the time to exhaustion (TEE) before and after a 4-week ketogenic diet.
Since this study is quite long, I will only focus on the performance aspect and muscle glycogen levels. The TEE test showed a huge difference between the participants. One topic improved the TEE score by 84 minutes in 4 weeks, the other showed an increase of 30 minutes, while two topics decreased by 50 minutes in total 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 values . This fact is already enough to claim that one can say goodbye to high performance.
Results of research into ketogenic diets
Let's 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 spontaneous calorie restriction. Because if you study a diet and body composition, any diet that limits calories will improve body composition.
In the third study, subjects consumed an average of 10, 000 kcal less in 30 days (minus 333 kcal per day! ) than on a regular diet, and of course lost weight.
It is likely that the ketogenic diet may still provide additional benefits in terms of changing body composition, but research has not yet shown this.
It must also be said that there is no literature that supports the idea that a ketogenic diet can help build muscle. It only helps to lose weight.
- Impaired performance at high intensity load. The first two studies showed a decrease in the subjects' ability to exercise with high intensity. This is possible for two reasons: firstly a decrease in intramuscular glycogen and secondly a decrease in liver glycogen stores during high intensity training.
- Reduction of intramuscular glycogen stores. Decreased athletic performance during high-intensity training is a sign of decreased intramuscular glycogen levels, studies have shown. It can also have a negative impact on the recovery of the exercisers and the ability of the muscles to grow in size.
Mistakes people make on ketogenic diets
Although there is no clear advantage over conventional calorie restriction, ketogenic diets can be a great tool for weight loss. If you want to lose weight (maybe even through muscle mass), you might want to give it a try. Now let’s look at the mistakes that people on a ketogenic diet often make so you don’t make them.
Lack of adequate adaptation phase
It can be very difficult for some people to switch to a ketogenic diet. Very often, people stop the diet in the adjustment phase without ending it. The adjustment phase can last for several weeks, where weakness is felt, consciousness is unclear, but after 2-3 weeks the energy level returns to normal.
If you want to try a ketogenic diet, give plenty of time to adjust.
Eating too much protein
As we have already learned, too much protein can prevent ketosis. People often compensate for low carbohydrate high protein diets on a ketogenic diet - this is a mistake.
Using a High Intensity Ketogenic Diet
In high-intensity anaerobic exercise, our body is primarily dependent on blood sugar stores, liver and muscle glycogen, and gluconeogenesis.
As ketogenic diets reduce muscle glycogen levels, it is very difficult to exercise with high loads.
Try a high carb diet instead of a ketogenic diet if you want to work out at high intensity.
Ketogenic diets prevent muscle gain
Ketogenic diets can help you lose weight but not gain muscle mass.
CD prevents you from training at high intensity and gaining muscle mass, so if these are the goals you are pursuing in your training, it is better to abandon the idea of practicing CD.
Consuming both protein and carbohydrates together gives a greater anabolic effect than consuming these nutrients alone. On a ketogenic diet, you reduce carbohydrates. And since you need both carbohydrates and protein for optimal muscle growth, you are missing one or both of these important 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.