What Science Says About Ketogenic Diets, and Why They Are Unlikely to Help You "dry out" much.
There are many different eating habits, many of which even have pretty names like the South Beach Diet, Weight Watchers Diet, Atkins Diet, HCG Diet, and the Volumetric Diet, Paleo diet, IIFYM (literally "If it fits your macros" - "If it fits your KBJU"), reverse carbohydrate loading (carbohydrate backloading), the ketogenic diet discussed today.
One of the most common diets used is ketogenic. Despite the fact that many people use it to burn fat, there is a lot of misinformation surrounding this diet.
Perhaps the most misunderstood aspect of the ketogenic diet is how it impacts athletic performance and your ability to gain muscle mass and increase strength.
The ketogenic diet - from the word "ketosis"
Ketosis is a metabolic disorder that occurs when the amount of carbohydrates in your diet is so low that the body only needs to use fatty acids and the metabolism of ketone bodies for energy. It all seems easy, but let's understand this process to understand why our bodies go into a state of ketosis.
Our body needs sufficient energy in the form of ATP to function.
ATP is a universal source of energy for all biochemical processes in living systems.
A person needs an average of 1, 800 calories per day (you can calculate your personal rate on a fitness calculator) to produce enough ATP and remain viable. At the same time, the midbrain needs around 400 kcal per day and uses almost only glucose as energy. This means that a person needs to consume 100 g 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 draining glucose from our brain. But we need our brains 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 working. Our liver can store an average of 100-120 grams of glucose. With a critical shortage of carbohydrates for the brain to function, the liver allows us to function normally throughout the day. In the end, however, the liver's glucose stores cannot be replenished quickly, and carbohydrates are not only needed by the brain, so we have problems.
Our muscles are also a huge storehouse for glucose - they contain 400-500 grams of glucose in the form of glycogen stores.
However, glycogen stores are not primarily used to nourish the brain. Unfortunately, our muscles cannot break down glycogen and release it into the bloodstream to eventually nourish our brains because there is no enzyme in the muscles that breaks down glycogen (glucose-6-phosphate dehydrogenase).
In the absence of carbohydrates, the liver begins to produce ketone bodies, which are transported through the bloodstream to our brain and other tissues that do not use fat for energy.
Let's briefly look at the biochemistry of these processes. When you burn fat, the fatty acid molecules in your body are converted into acetyl-CoA, which in turn combines with oxaloacetate to initiate the Krebs cycle.
During ketosis, our liver consumes as much fat as energy that excess acetyl-CoA produces ketone bodies (beta-hydroxybutyrate, acetoacetic acid and acetone).
Gradually,with a regular carbohydrate deficit, the body reaches such a state that this process is ongoing and the level of ketones in the blood increases noticeably. 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-carb diet?
A low-carb diet and a ketogenic diet are not the same thing.
The low-carbohydrate diet uses fats 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 a 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 range between 0. 5 and 3. 0 mM / L. You can even buy blood ketone test strips and measure your own.
A low-carbohydrate diet limits the amount of carbohydrates in the diet (often just under 100 grams per day), but beta-hydroxybutyrate levels don't reach 0. 5 and 3. 0 mM / L.
How to eat a ketogenic diet
As explained 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 in ketosis varies from person to person. Typically, however, you can consume up to 12% of your calories from carbohydrates and stay in ketosis.
Protein intake is also very important. Most athletes have made it clear that they need to consume large amounts of protein. Perhaps this is one of the factors contributing to an unsuccessful ketogenic diet.
As mentioned earlier, when consumed in high doses (during gluconeogenesis),protein can break down into glucose so that you cannot enter ketosis.If you consume more than 1. 8 grams of protein per 1 kg of body weight, this amount is basically enough to get out of ketosis.
Ideally, your diet should be around 75% fat, 5% carbohydrates, and 20% protein to improve ketogenic status and maintain muscle mass.
"Adaptation" phase in the ketogenic diet
If you read the ketosis literature, you will see a general trend. There is the most distinctive "adjustment" phase in which people experience a cloudy mind, feel sluggish, and lose energy. Basically, people feel very bad for the first few weeks on a ketogenic diet. This is likely due to the lack of essential enzymes in our body that are needed to efficiently oxidize certain elements.
To survive, our bodies try to rewire to use other energy resources and learn to rely only on fat and ketone bodies. Usually, all of these symptoms will go away after 4-6 weeks of adjusting to the ketogenic diet.
Ketosis and Athletic Performance: An Overview of Scientific Research
Let's look at some studies that might answer this question.
Study No. 1The first study involved 12 people (7 men and 5 women aged 24 to 60 years) who took one self-prescribed for an average of 38 daysgot ketogenic diet. The subjects carried out moderate to intensive training, their blood count, their body composition and their maximum oxygen consumption were measured.
The authors of the study themselves come to the conclusion: “The radical carbohydrate reduction had no statistically significant influence on mileage. As measured by the time the subjects began to fatigue and the maximum oxygen consumption, but the body weight composition improved, the participants lost 3. 4 kg of fat and gained 1. 3 kg of muscle mass. "
Thus, the study participants lost weight, but showed no noticeable change in athletic performance. In addition, the subjects decreased the body's ability to recover.
Study No. 2Another study included 8 men aged around 30 years with at least 5 years of training experience. The test subjects took part in a 4-week mixed + ketogenic cross-style diet and completed longer stationary bike training sessions of varying intensity.
As in the first study, the ketogenic diet also had a positive effect on the composition of body mass..
Interestingly, the relative values of maximum oxygen consumption and oxygen consumption at the anaerobic threshold increased significantly in the ketogenic diet. The increase in maximum oxygen consumption can be explained by a decrease in body weight. However, the maximum workloadand the workload at anaerobic threshold were lower after the ketogenic diet.
This means that the ketogenic dietresulted in weight loss, but also a significant decrease in explosive power and the ability to exercise at high intensity. Do you want to be stronger and train harder? Then don't think the ketogenic diet is a good choice for that.
Study No. 3A third study looked at how a 30-day ketogenic diet (4. 5% calories from carbohydrates) affects performance in thefollowing exercises: hanging leg raises, push-ups on the floor, push-ups on parallel bars, pull-ups, squat jumping and 30-second jumps. The scientists also measured the body composition of the participants.
Here are the conclusions:
- The ketogenic diet caused a "spontaneous reduction in calorie intake" compared to the normal diet.
- No loss of performance was noted on the ketogenic diet tested, but no performance improvement was noted.
As in other studies, there was a noticeable difference in body weight composition after the ketogenic diet: the participants were able to lose weight. It should be noted, however, that the participants selected for this study were already quite “dry” (around 7% body fat).
It's also important to mention that none of these tests viewed the glycolysis process as an energy source. Rather, they were tests that tested explosion resistance, phosphagen system, and muscle fatigue tests.
Study No. 4In this study, 5 experienced cyclists performed the test for maximum oxygen consumption and the test until exhaustion before and after a 4-week ketogenic diet (TEE).
Since this study is quite lengthy, I just want to focus on the performance aspect and muscle glycogen levels. The TEE test showed a big difference between the participants. One subject improved the TEE values by 84 minutes in 4 weeks, the second showed an increase of 30 minutes, while two subjects fell by a total of 50 minutes and one subject remained unchanged:
In terms of muscle glycogen stores, a muscle biopsy showed thatglycogen stores were almost half of normalafter the ketogenic diet. This fact is enough to say that we can say goodbye to high performance.
Research results on ketogenic diets
Let's look at what these 4 studies have in common:
Improved body composition.Every study resulted in a qualitative improvement in body composition. However, it is debatable that this is the miraculous effects of the ketogenic diet, rather than a spontaneous calorie restriction. Because if you are into any type of diet and body composition, any diet that restricts calories will improve body composition.
In the third study, the subjects consumed an average of 10, 000 kcal less (minus 333 kcal per day! ) in 30 days than with a normal diet, and of course they lost weight.
It's likely that the ketogenic diet has additional benefits in terms of body composition changes, but research hasn't shown this yet.
It should also be said that there is no literature to support the idea that a ketogenic diet can help build muscle. It only helps you lose weight.
- Decreased performance in high-intensity training sessions. The first two studies showed a decrease in 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 intense exercise.
- Reduction of intramuscular glycogen stores. Decreased athletic performance during intense exercise is a sign of decreased intramuscular glycogen levels, studies have shown. It can also adversely affect the recovery of exercising athletes and the ability of muscles to grow in size.
Mistakes people make on ketogenic diets
While there is no clear advantage over traditional calorie restriction, ketogenic diets can be a good tool for weight loss. If you want to lose weight (maybe through muscle mass) then maybe you should give it a try. Now let's look at the mistakes people on a ketogenic diet often make to keep you from making them.
Lack of an appropriate adjustment phase
Switching to a ketogenic diet can be very difficult for some people. Very often people stop the diet without stopping during the adjustment phase. The adjustment phase can take several weeks. During this time, weakness is felt, consciousness is clouded, but after 2-3 weeks the energy levels return to normal.
If you want to try a ketogenic diet, allow enough time to adjust.
Eating too much protein
As we've already learned, too much protein can prevent ketosis. People often replace low-carbohydrate with high-protein on a ketogenic diet - this is a mistake.
Using a high-intensity ketogenic diet
For anaerobic exercises with high intensity, our body is mainly dependent on blood sugar stores, liver and muscle glycogen and gluconeogenesis.
Since ketogenic diets lower muscle glycogen levels, it is very difficult to exercise with high loads.
Try a carbohydrate alternative diet instead of a ketogenic diet if you want to exercise at high intensity.
Ketogenic diets prevent muscle building
Ketogenic diets can help you lose weight but not gain muscle mass.
CD prevents you from exercising at high intensity and building muscle mass. So if these are the goals you are pursuing in your workout, then it is better to abandon the idea of CD practice.
If you consume both protein and carbohydrates together, it has a more anabolic effect than if you consume these nutrients alone. On a ketogenic diet, you cut down on 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 mass and improving athletic performance. However, they can help you lose weight - just like any other calorie restriction that is below your personal daily value.