The ketogenic diet (keto diet) contains approximately 90-99% of calories from fat and protein and only 1-10% from carbohydrates.Eating this way may have some benefits for weight loss or reducing the number of epileptic seizures.
However, as a new study has found, following the keto diet provides health benefits only for a short period of time - 1-2 weeks - after which its negative effects begin to appear.
What is the keto diet?
The ketogenic diet (or keto diet for short) is a very low-carb, high-fat diet that may have some health benefits.
More than 20 studies have shown that this type of diet can help you lose weight and improve your health.Ketogenic diets may even have some benefits for diabetes, brain cancer, epilepsy and Alzheimer's disease.
The ketogenic diet is a very low-carb (no more than 1-10%), high-fat diet that has many similarities to the Atkins diet and the low-carb diet.Following this diet leads to a sharp reduction in carbohydrates and replacing them with fats and proteins.This greatly reduces the body's use of carbohydrates and switches the body to use fat as its main source of energy.If there is little glucose in the body, the liver processes fat into fatty acids and ketone bodies.
When the amount of ketone bodies in the body increases, ketosis occurs and the brain begins to use these ketone bodies instead of carbohydrates.When this happens, the body becomes more efficient at burning fat for energy.
The ketogenic diet can significantly lower blood glucose and insulin levels.This, along with the increase in the amount of ketones, shows some beneficial benefits for the body.
However, the keto diet can be potentially dangerous for people with type 1 diabetes.
The benefits of the keto diet
A study of 63 people created two groups: either a low-fat diet group or a low-carb diet group.The group of people on a low-fat diet were restricted in calories.This study continued for 12 months.
The low-carb group lost more weight, 7.3% of total body weight, compared to the low-fat group, which lost 4.5%.The difference was statistically significant at 3 and 6 months, but not at 12 months.At the end of the experiment, there was no difference in weight between the groups of people.
Of note, the low-carb (keto diet) group had higher levels of triglycerides and HDL in the blood, but other biomarkers were similar between the groups.
If we analyze the 23 known clinical studies on people evaluating the effect of low-carbohydrate diets (keto diets), we can formulate the general conclusions of these studies.Most studies achieved statistically significant differences in weight loss (always in favor of low-carb diets).
A few other factors are worth mentioning:
- Low-carb diets often resulted in 2-3 times more weight loss than low-fat diets.In some cases there were no significant differences.
- In most cases, calories were restricted in the low-fat groups, while the low-carb groups were able to eat as much as they wanted.
- When all groups of subjects restricted calories, the low-carb diets still showed greater reductions in body weight, although this was not always significant.
- There was only one study in which the low-fat diet group lost more weight, although the difference was small (0.5 kg) and not statistically significant.
- In some studies, weight loss was greater at first.People then start to gain the weight back over time and after going off the keto diet.
- When the scientists looked at the amount of belly fat (the bad visceral fat), low-carb diets had a clear advantage in reducing this type of fat.
Two of the main reasons that low-carb diets (keto diets) are so effective for weight loss are the high protein content of the food and the appetite-suppressing effects of this eating style.This results in a dramatic reduction in calorie intake.
Harmful effects of the keto diet
Clinical studies show that the keto diet can improve a person's health over a short period of time (up to 12 months) by reducing the risk of developing type 2 diabetes and, as a result, reducing inflammation caused by fat cells.
A study conducted at Yale University found that the positive and negative effects of diet are related to the behavior of immune cells called gamma delta T cells (γδ T cells), tissue-specific cells that reduce the risk of diabetes and inflammation.
Gamma delta T cells are immune T cells that have the distinctive T cell receptor (TCR) on their surface.Most T cells are αβ (alpha beta) T cells with a TCR composed of two glycoprotein chains called the α (alpha) and β (beta) TCR chains.In contrast, gamma delta (γδ) T cells have a TCR consisting of a γ (gamma) chain and a δ (delta) chain.This group of T cells tends to be less abundant—about 4–10% of all T cells—than αβ T cells, but has the highest abundance in the intestinal mucosa, within a population of lymphocytes known as intraepithelial lymphocytes (IELs).
Gamma-delta immune T cells are characterized by a number of characteristics that place them within the limits of the more primitive innate immune system in evolutionary terms, which provides a rapid response to a variety of pathogens, and the adaptive immune system, where lymphocytes coordinate their actions much more slowly.At the same time, T cells (γδ) have the ability to have long-term memory in order to respond even faster to pathogens when they are encountered again in the future.
The keto diet leads to increased presence of immune T cells (γδ) and their depletion in adipose tissue.
This diet tricks the body into burning fat, said the author of the study, Dr.Vishwa Deep Dixit of the Yale School of Medicine.When the body's glucose levels decrease due to the low carbohydrate content of the food, the body behaves as if it is in a fasted state, even though it is not, and begins to burn fat instead of carbohydrates.
This causes the body to use β-hydroxybutyrate (beta-hydroxybutyric acid) to produce ATP and reduces inflammation mediated by NLRP3, a cytosolic protein involved in the activation of the inflammatory interleukins IL-1b and IL-18.
The process of reducing carbohydrates in food, in turn, begins to produce ketone bodies (ketones) as an alternative fuel source.When the body burns ketone bodies, protective gamma delta T cells spread throughout the body.And the number of these protective immune cells in adipose tissue is significantly reduced.As the γδ T cells in the adipose tissue decrease, the level of inflammation that these cells previously contained begins to increase.Inflammation is known to stimulate the accumulation of fat cells.
Furthermore, mice lacking γδ immune T cells showed impaired glucose homeostasis, leading to increased blood glucose levels.
The keto diet reduces the risk of diabetes and inflammation, and also improves the body's metabolism, the scientists noted.After a week on the keto diet, the mice showed reduced blood sugar and inflammation.
But when the body is in this "starvation-not-starvation" mode for a long enough time (more than 1-2 weeks), the accumulation of fat occurs simultaneously with its breakdown, scientists have discovered.When the mice continued to eat a high-fat, low-carb diet, they consumed more fat than their bodies could burn.And then the signs of diabetes and obesity began to rise.
Side effects of the keto diet
Although the ketogenic diet is safe for healthy people, there may be some initial side effects as your body adjusts to the new diet.
This presentation is often called keto flu and usually ends within a few days.Keto flu includes low body energy and impaired mental function, increased hunger, sleep problems, nausea, digestive disturbances, and decreased performance during exercise.
To minimize this, you can start a low-carb diet for the first few weeks.This can train your body to burn more fat before you completely eliminate carbohydrates from your diet.
The keto diet can also change your body's water and mineral balance, so adding extra salt to your meals or taking a mineral supplement can help.Try taking 3000-4000 mg of sodium (salt), 1000 mg of potassium and 300 mg of magnesium per day to reduce side effects.