What the Science Says About Ketogenic Diets and Why They Probably Won't Help You 'Dry Up' Much.
There are many different eating styles, many of which even have pretty names, such as South Beach Diet, Weight Watchers Diet, Atkins Diet, HCG Diet, Volumetric Diet, Paleo Diet, IIFYM(literally "if it suits your macros" - "if it fits your KBJU"), reverse carb loading (carb backloading), ketogenic diet, which will be discussed today.
One of the most widely used diets is ketogenic. Despite the fact that many people use it for fat burning, there is a lot of misinformation surrounding this diet.
Perhaps the most misunderstood aspect of the ketogenic diet is how it affects athletic performance and your ability to gain muscle mass and increase your strength.
The ketogenic diet - from the word "ketosis"
Ketosis is a metabolic state that occurs when the amount of carbohydrate in your diet is so low that the body simply has to use fatty acids and the body's metabolism for ketone for energy. It seems 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 energy source 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 stay viable. At the same time, the midbrain requires about 400 kcal per day and almost only uses glucose for energy. This means that a personneeds to consume 100g of glucose per 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 we are depriving our brains of glucose. But we need our brains to function in one way or another. Fortunately, the liver stores glucose in the form of glycogen and can give a small amount of it to our brain to keep it functioning. Our liver can store an average of 100 to 120 grams of glucose. With a critical lack of carbohydrates for brain function, the liver allows us to function normally throughout the day. Ultimately, however, the liver's glucose stores cannot be replenished quickly and carbohydrates aren't just needed by the brain, so we have problems.
Our muscles are also a huge store of glucose - they contain 400-500 grams of glucose as glycogen stores.
However, glycogen stores are not primarily designed to fuel the brain. Unfortunately, our muscles cannot break down glycogen and get it into the bloodstream and ultimately nourish our brain, due to the lack of an enzyme in muscles that breaks down glycogen (glucose-6-phosphate dehydrogenase).
In the absence of carbohydrates, the liver begins to produce ketone bodies which are transported by the bloodstream to our brains and other tissues which 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 into acetyl-CoA, which in turn combines with oxaloacetate to start the Krebs cycle.
During ketosis, our liver uses so much fat and energy that an excess of Acetyl-CoA begins to produce ketone bodies (beta-hydroxybutyrate, acetoacetic acid, and acetone).
Gradually,with a regular deficit of carbohydrates, the body reaches such a state that this process begins to occur constantly, and the level of ketones in the blood increases noticeably, then we can say that weare officially in ketosis.
What is a ketogenic diet 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 fats and carbohydrates for our daily energy needs. Our bodies don't store ketones in the blood, and our tissues don't use ketones for energy.
With a ketogenic diet, our body reaches the point where ketones 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 ketonemia test strips and measure yours.
A low-carb diet limits the amount of carbohydrates in the diet (often just below 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 saw above, the ketogenic diet should be high in fat and low in carbohydrates.
In traditional, strict ketogenic diets, 70-75% of daily calories should come from fat and only 5% from carbohydrates. The amount of carbohydrate you can consume while staying in ketosis varies from person to person, but you can generally consume up to 12% of your calories from carbohydrates and stay in ketosis.
Protein intake is also very important. Most of the practitioners have got it into their heads that they need to consume large amounts of protein, this may be one of the factors in the failure of ketogenic diets.
As we have seen before, the proteinwhen consumed in large doses can be broken down into glucose (during gluconeogenesis) and therefore you cannot 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, in order to improve ketogenic status and maintain lean muscle mass, your diet should be around 75% fat, 5% carbohydrate, and 20% protein.
'Adaptation' phase to a ketogenic diet
If you read the literature on ketosis, you will see a general trend. There is the most distinctive “adjustment” phase in which people experience a cloudy state of mind, feel lazy, and lose energy. Basically, people feel terrible 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 effectively oxidize certain elements.
To survive, our body tries to rewire itself to use other energy resources and learn to rely only on fats and ketones. Usually, after 4-6 weeks of adapting to the ketogenic diet, all of these symptoms go away.
Ketosis and athletic performance: a review of the scientific research
Let's take a look at some studies that may answer this question.
Study # 1The first study involved 12 people (7 men and 5 women, aged 24 to 60) who were on an auto-ketogenic diet. prescribed for 38 days on average. The subjects performed medium to intense training, their blood count, body composition, and peak oxygen uptake were measured.
The study authors themselves conclude: “The drastic reduction in carbohydrates did not statistically significantly affect running performance, judging by when subjects started to tire andmaximum oxygen uptake level, but body mass composition improved, participants lost 3. 4 kg of fat, and gained 1. 3 kg of lean muscle mass. "
Thus, the study participants lost weight, but showed no noticeable change in their athletic performance. In addition, the subjects decreased the body's ability to recover.
Study n ° 2Another study involved 8 men of about 30 years old with at least 5 years of training experience. The subjects followed a 4-week mixed + ketogenic crossover diet and exercised prolonged on a stationary 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 peak oxygen uptake and anaerobic threshold oxygen uptake increased significantly with the ketogenic diet. The increase in maximal oxygen uptake may be explained by a decrease in body weight. However, peak workload and anaerobic threshold workloadwere 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 be stronger and train harder? 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% calories from carbohydrates) affects exercise performancefollowing: Hanging Leg Raise, Floor Push-ups, Parallel Bar Push-ups, Pull-ups, Crouch and 30-Second Hops. 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 performance loss was found with the tested ketogenic diet exercise, however, 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. It should be borne in mind, 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 considered the glycolysis process to be a source of energy, but rather tests that tested explosive strength, the phosphagenic system, and muscle fatigue tests.
Study # 4In this study, 5 experienced cyclists performed the maximum oxygen uptake test and the time before exhaustion (TEE) test before andafter a 4 week ketogenic diet.
As this research is quite long, I want to focus only on the performance aspect and muscle glycogen levels. The TEE test showed a huge difference between the participants. One subject improved TEE scores by 84 minutes in 4 weeks, the second showed an increase of 30 minutes, while two subjects fell 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 enough to say that high performance can be said goodbye.
Ketogenic Diet Research Results
Let's see what these 4 studies have in common:
Improved body composition.The result of each study was a qualitative improvement in body composition. However, it is controversial that this is the miracle effect of the ketogenic diet, rather than spontaneous calorie restriction. Because if you research 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 with a regular diet, and of course they lost weight.
It's likely that the ketogenic diet may still offer additional benefits in terms of body composition changes, but research has yet to show it.
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 in losing weight.
- Decreased performance at high intensity loads. The first two studies showed a decrease in the ability of subjects 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 in intramuscular glycogen stores. Decreased 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 exercising athletes and the ability of muscles to grow larger.
Mistakes People Make About 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 (maybe also through muscle mass), you might want to give it a try. Now let's take a look at the mistakes people on 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. Very often, people stop the diet during the adaptation phase without completing it. The adaptation phase can last for several weeks, during which time weakness is felt, consciousness is cloudy, but after 2-3 weeks energy levels return to normal.
If you want to try a ketogenic 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 carbs with high protein on the ketogenic diet - that's a mistake.
Using a ketogenic diet with high exertion
For high intensity anaerobic exercise, our body mainly depends on blood sugar 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 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 workout then it is best to ditch the idea of practicing CD.
Consuming protein and carbohydrates together produces a greater anabolic effect than consuming these nutrients alone. With a ketogenic diet, you reduce your carbohydrate intake. And because you need both carbohydrates and protein for optimal muscle growth, you're missing one or both key nutrients.
Conclusion: Ketogenic diets are neither optimal nor effective for building muscle mass and improving athletic performance. However, they can help you lose weight - like any other calorie restriction lower than your personal daily value.