What science says about ketogenic diets and why they probably won't help you "dry out" too much.
There are many different eating patterns, many of which even have beautiful names, like South Beach Diet, Weight Watchers Diet, Atkins Diet, HCG Diet, Volumetric Diet, paleo diet, IIFYM (literally“If It Fits Your Macros” - “if it fit in your KBJU”), reverse the carbohydrate load (carbs-backloading), the ketogenic diet, which will be discussed today.
One of the most 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 its 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 the diet is so low that the body simply needs to use the fatty acids and 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.
Our bodies need enough energy in the form of ATP to function.
ATP is a universal source of energy for all biochemical processes in living systems.
An average person needs 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 requires about 400 kcal per day and uses almost only glucose as energy. This means that aperson needs 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 are depriving 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 the brain to keep it functioning. Our liver can store an average of 100-120 grams of glucose. With a critical lack 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 for the brain, which is why we have problems.
Our muscles are also a large deposit of glucose - they contain 400-500 grams of glucose in the form of glycogen stores.
However, glycogen stores are not designed primarily to feed the brain. Unfortunately, our muscles are unable to break down glycogen and put it in the bloodstream to eventually feed our brain, due to the lack of an 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 the 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 to acetyl-CoA, which in turn combines with oxaloacetate to start the Krebs cycle.
During ketosis, our liver uses so much fat as energy that excess acetyl-CoA begins to produce ketone bodies (beta-hydroxybutyrate, acetoacetic acid and acetone).
Gradually,with a regular deficit of carbohydrates, the body reaches a state that this process begins to occur constantly and the level of ketone bodies in the blood visibly increases, so we can say that we are officially in a state of ketosis.
What a ketogenic diet is and how it differs from a "low carb" diet
A low-carb diet and a ketogenic diet are not the same thing.
The low-carb diet uses fat 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. During this diet-induced ketosis, beta-hydroxybutyrate levels can be between 0, 5 and 3. 0 mM / L. You can even purchase blood ketone test strips and measure them yourself.
A low carbohydrate diet restricts 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 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 generally consume up to 12% of your carbohydrate calories and stay in ketosis.
Protein intake is also very important. Most exercise practitioners have put it into their heads that they should consume large amounts of protein, perhaps this is one of the factors of unsuccessful ketogenic diets.
As we discussed earlier,protein when consumed in high doses can be broken down into glucose (during gluconeogenesis) and therefore you will not be able to go into 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 out of ketosis.
Ideally, to improve ketogenic status and maintain lean muscle mass, your diet should be approximately 75% fat, 5% carbohydrates and 20% protein.
"Adaptation" phase in a ketogenic diet
If you read the ketosis literature, you will see a general trend. There is the most distinct "adaptation" phase in which people experience a cloudy mind, feel sluggish and lose energy. Basically, people feel very bad in the first few weeks of a ketogenic diet. This is probably due to the lack of essential enzymes in our body, which are necessary to efficiently oxidize certain elements.
To survive, our body tries to reconnect to use other energy resources and learn to rely only on fat and ketone bodies. Typically, after 4-6 weeks of adapting to the ketogenic diet, all of these symptoms disappear.
Ketosis and athletic performance: a review of scientific research
Let's take a look at some studies that may answer that question.
Study # 1The first study involved 12 people (7 men and 5 women, aged 24-60) who were on a self-prescribed ketogenic diet foran average of 38 days. The subjects underwent medium to intense training, their blood counts, body composition and maximum oxygen consumption were measured.
The study authors themselves conclude: “The radical reduction in carbohydrates did not show a statistically significant effect on running performance, judging by the time when individuals started to tire and the level of maximum oxygen consumption, but thebody mass composition 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. In addition, the subjects decreased the body's ability to recover.
Study # 2Another study involved 8 men in their 30s with at least 5 years of training experience. The subjects followed a 4-week mixed + ketogenic cross-diet and did prolonged exercise on an exercise bike at varying intensities.
The ketogenic diet also had a positive effect on body mass composition, as in the first study.
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 the decrease in body weight. However,maximum workload and anaerobic threshold workload 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 more? So, don't assume that the ketogenic diet is a good choice for this.
Study # 3A third study examined how a 30-day ketogenic diet (4. 5% carbohydrate calories) affects performance in the following exercises: suspended legs, floor push-ups, parallel bar push-ups, push-ups, squats and 30-second jumps. The scientists 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 loss of performance was found with the tested ketogenic diet exercise; however, no performance improvement was found.
As in other studies, there was a notable difference in the composition of body weight after the ketogenic diet: the participants managed to lose weight. However, it must be kept in mind that the participants selected for this study were already quite “dry” (about 7% of body fat).
It is also important to mention that none of these tests looked at the process of glycolysis as an energy source, they were more tests that tested tests of explosive strength, phosphogenic system and muscle fatigue.
Study No. 4In this study, 5 experienced cyclists performed the maximum oxygen consumption test and the time to exhaustion test (TEE) before and after aketogenic diet for 4 weeks.
As this research is quite long, I want to focus only on the performance aspect and the levels of muscle glycogen. The TEE test showed a big difference between the participants. One subject improved the TEE scores by 84 minutes in 4 weeks, the second showed an increase of 30 minutes, while two subjects dropped 50 minutes in total, and one subject 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 sufficient to affirm that the high performance can be said soon.
Ketogenic diets search results
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 spontaneous calorie restriction. Because if you do some research on 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 in 30 days (333 kcal less per day! ) than with a regular diet and, of course, lost weight.
It is likely that the ketogenic diet still offers 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 to support the idea that a ketogenic diet can help build muscle. It only helps you lose weight.
- Deteriorated performance on high-intensity loads. The first two studies showed a decline in individuals' ability to exercise at high intensity. This is possible for two reasons: first, a decrease in intramuscular glycogen and, second, a decrease in hepatic glycogen stores during high-intensity training.
- Reduction of intramuscular glycogen stores. The decrease in athletic performance during high-intensity training is a sign of decreased levels of intramuscular glycogen, studies have shown. It can also negatively affect the recovery of athletes who exercise and the ability of muscles to grow.
Mistakes people make on ketogenic diets
Although there is no clear benefit over conventional calorie restriction, ketogenic diets can be a good tool for losing weight. If you want to lose weight (maybe also through muscle mass), maybe you should try. Now, let's examine the mistakes people who follow a ketogenic diet often make so that you don't make them.
Lack of adequate adaptation phase
Switching to a ketogenic diet can be very difficult for some people. Often, people abandon the diet during the adaptation phase without completing it. The adaptation phase can last for several weeks, during which time you feel weak, consciousness is blurred, but after 2-3 weeks the energy levels return to normal.
If you want to try a ketogenic diet, allow plenty of time to adapt.
Eating too much protein
As we have already learned, too much protein can prevent ketosis. In a ketogenic diet, people often replace low-protein carbohydrates with high-protein content - this is a mistake.
Using a high intensity effort ketogenic diet
For high-intensity anaerobic exercise, our body depends primarily on blood glucose stores, liver and muscle glycogen and gluconeogenesis.
Since ketogenic diets reduce muscle glycogen levels, it is very difficult to train with high loads.
Try an alternative carbohydrate diet instead of a ketogenic diet if you want to train at high intensity.
Ketogenic diets prevent muscle gain
Ketogenic diets can help you lose weight, but not gain muscle.
The CD will prevent you from training at high intensity and gain lean muscle mass, so if those are the goals you are pursuing in your training, it is best to give up the idea of practicing the CD.
Consuming proteins and carbohydrates together produces a greater anabolic effect than consuming just those nutrients. In a ketogenic diet, you reduce carbohydrates. And since you need carbohydrates and proteins for optimal muscle growth, one or both essential nutrients are missing.
Result: Ketogenic diets are neither ideal nor effective for building muscle mass and improving athletic performance. However, they can help you lose weight - just like any other calorie restriction below your personal daily value.