What the science says about ketogenic diets and why they probably won't help you "dry out" much.
There are many different eating patterns, many of which even have pretty names, such as South Beach diet, weight watchers, Atkins diet, HCG diet, volumetric diet, paleo diet, IIFYM (literally"If it fits your macros" - "if it fits your KBJU"), reverse carbohydrate loading (carbohydrate loading), the ketogenic diet, to be discussed today.
One of the most widely 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 and increase strength.
The ketogenic diet - from the word "ketosis"
Ketosis is a metabolic state that occurs when the amount of carbohydrates in your diet is so low that the body simply has to use the fatty acids and metabolism of the ketone body for energy. It seems that 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.
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 remain viable. At the same time, the midbrain requires about 400 kcal per day and uses almost only glucose for energy. This means that aperson needs to consume 100 g of glucose per day just to maintain normal brain function.
What does this have to do with ketosis? With a ketogenic diet, we eliminate almost all carbohydrates from our diet, which means that we are starving 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. However, in the end, the liver's glucose stores cannot be replenished quickly and carbohydrates are not only needed by the brain, which is why we have problems.
Our muscles are also a large store of glucose: they contain between 400 and 500 grams of glucose in the form of glycogen stores.
However, glycogen stores are not primarily designed to fuel the brain. Unfortunately, our muscles are unable to break down glycogen and put it into the bloodstream to eventually fuel our brain, due to a 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 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 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).
Little by little,with a regular carbohydrate deficit, 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 astate 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 fat and carbohydrates for our daily energy needs. Our bodies do 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 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 your own.
A low carbohydrate diet restricts the amount of carbohydrates in the diet (often a little less than 100 grams per day), but beta-hydroxybutyrate levels do not reach 0. 5 and 3. 0 mM / L.
How to follow a ketogenic diet
As we discussed earlier, 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, but you can generally consume up to 12% of your calories from carbohydrates and remain in ketosis.
Protein intake is also very important. Most athletes have gotten it into their heads that they must consume large amounts of protein, perhaps this is one of the factors of failed ketogenic diets.
As we discussed earlier, proteinwhen consumed in high doses can break down into glucose (during gluconeogenesis) and therefore cannot enter ketosis.Basically, if you consume more than 1. 8 grams of protein per 1 kg of body weight, then this amount will be enough to get you 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 of a ketogenic diet
If you read the literature on ketosis, you will see a general trend. There is the most distinctive "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 depend only on fat and ketones. Usually, after 4-6 weeks of adaptation to the ketogenic diet, all these symptoms disappear.
Ketosis and athletic performance: a review of the scientific research
Let's take a look at some studies that can answer this question.
Study no. # 1The first study involved 12 people (7 men and 5 women, 24 to 60 years of age) who were on a self-prescribed ketogenic diet for an average of 38 days. Subjects underwent medium to intense intensity training, blood counts, body composition, and maximal oxygen consumption were measured.
The study authors themselves conclude: “Radical carbohydrate reduction did not show statistically a significant effect on running performance, judging by the time subjects began to fatigue and the level of peak oxygen consumption, but body mass composition improved, participants lost 3. 4 kg of fat and gained 1. 3 kg of lean muscle mass. "
Therefore, the study participants lost weight, but showed no noticeable change in athletic performance. Additionally, the subjects decreased the body's ability to recover.
Study no. 2Another study involved 8 men in their 30s with at least 5 years of training experience. Subjects followed a 4-week crossover-style mixed + ketogenic diet and did prolonged stationary bike workouts at different 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 uptake and oxygen uptake at the anaerobic threshold were significantly increased on the ketogenic diet. The increase in maximum oxygen consumption can be explained by a decrease in body weight. However,the maximum workload and the workload at the anaerobic threshold were lower after the ketogenic diet.
This means that the ketogenic dietresulted in weight loss, but also a significant decrease in explosive strength and the ability to train at high intensity. Do you want to get stronger and train harder? So don't assume the ketogenic diet is a good option for this.
Study no. ° 3A third study examined how a 30-day ketogenic diet (4. 5% of calories from carbohydrates) affects performance in the following exercises: hanging leg raises, leg curlsthe floor, push-ups with parallel bars, chin-ups, squat jumps and 30-second jumps. The scientists also measured the body composition of the participants.
These 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 ketogenic diet exercise tested, however no improvement in performance was found.
As with other studies, there was a notable difference in body weight composition after the ketogenic diet - participants were able to lose weight. However, it should be noted that the participants selected for this study were already quite dry (around 7% body fat).
It is also important to mention that none of these tests considered the glycolysis process as an energy source, they were more tests that tested explosive strength, phosphagenic system and muscle fatigue tests.
Study no. ° 4In this study, 5 experienced cyclists performed the maximal oxygen uptake test and the time to exhaustion test (TEE) before and after a 4-week ketogenic diet.
Since this research is quite extensive, I want to focus only on the performance aspect and muscle glycogen levels. The TEE test showed a large difference between the participants. One subject improved TEE scores by 84 minutes in 4 weeks, the second showed a 30 minute increase, while two subjects decreased 50 minutes in total and one subject was unchanged:
With respect to muscle glycogen stores, a muscle biopsy showed that glycogen storesafter the ketogenic diet were almost half of their normal values . This fact is enough to say that high performance can be said goodbye.
Results of research on ketogenic diets
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 miracle effect of the ketogenic diet, rather than spontaneous caloric restriction. Because if you do any research on 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 in 30 days (minus 333 kcal per day! ) than on a regular diet, and of course lost weight.
The ketogenic diet may still offer additional benefits in terms of changes in body composition, but research has yet to prove 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.
- Impaired performance in high intensity training. The first two studies showed a decrease in the 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 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 adversely affect the recovery of athletes who exercise and the ability of muscles to increase in size.
Mistakes people make on ketogenic diets
While there is no clear benefit over conventional calorie restriction, ketogenic diets can be a good weight loss tool. If you are looking to lose weight (perhaps also through muscle mass), maybe you should give it a try. Now let's look at the mistakes people on a ketogenic diet make so you don't make them.
Lack of an adequate adaptation phase
Switching to a ketogenic diet can be very difficult for some people. Very often, people abandon the diet during the adaptation phase without completing it. The adaptation phase can last several weeks, during which weakness is felt, consciousness becomes cloudy, but after 2-3 weeks energy levels return to normal.
If you want to try a keto diet, allow plenty of time to adjust.
Eating too much protein
As we've already learned, too much protein can prevent ketosis. People often replace low carbohydrates with high protein on a ketogenic diet; this is a mistake.
Use of high intensity ketogenic diet
For high intensity anaerobic exercise, our body relies primarily on stores of blood glucose, liver and muscle glycogen, and gluconeogenesis.
Since ketogenic diets reduce muscle glycogen levels, it is very difficult to train with heavy loads.
Try an alternating 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 mass.
CD will prevent you from training at high intensity and gaining lean muscle mass, so if these are the goals you are pursuing in your training, then it is better to give up the idea of practicing CD.
Consuming protein and carbohydrates together produces a greater anabolic effect than consuming these nutrients alone. On a ketogenic diet, cut down on carbohydrates. And since you need both carbohydrates and protein for optimal muscle growth, you are missing one or both of these key nutrients.
Bottom Line: 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.