The ketogenic diet contains approximately 90-99% of calories from fat and protein and only 1-10% from carbohydrates.Eating it this way may offer some benefits for weight loss or reducing the number of seizures.
However, as a new study found, following the keto diet provides health benefits only for a short period of time - 1-2 weeks - after which its negative effects start 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 benefit 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 the 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 incredibly efficient at burning fat for energy.
The ketogenic diet can significantly lower blood glucose and insulin levels.This, combined with the increased amount of ketones, shows some beneficial benefits for the body.
However, the keto diet can be potentially dangerous for people with type 1 diabetes.
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 low-fat diet group was calorie restricted.This study continued for 12 months.
The low-carb group lost more weight, 7.3% of their 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 increased blood triglyceride and HDL levels, but other biomarkers were similar between groups.
If we analyze the known 23 human clinical studies evaluating the effect of low-carbohydrate diets (keto-diets), we can formulate the general conclusions of these studies.Most studies found statistically significant differences in weight loss (always in favor of low-carb diets).
There are a few other factors worth noting:
- Low-carb diets often resulted in 2-3 times more weight loss than low-fat diets.In some cases there was no significant difference.
- In most cases, calories were restricted in the low-fat groups, while the low-carb groups could 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 early on.People then start to regain their weight over time and after they go off the keto diet.
- When scientists looked at the amount of belly fat (bad visceral fat), low-carb diets had a clear advantage in reducing this type of fat.
Two of the main reasons why 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 diet.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 in the short term (up to 12 months) by reducing the risk of developing type 2 diabetes and thereby 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 γ-delta T cells (γδ T cells), tissue-specific cells that reduce the risk of diabetes and inflammation.
γ-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 consisting of two glycoprotein chains called the α (alpha) and β (beta) chains of the TCR.In contrast, γ-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, in a population of lymphocytes known as intraepithelial lymphocytes (IELs).
Gamma-delta immune T cells are characterized by a number of features that place them within the boundaries of the more evolutionarily primitive innate immune system, 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, (γδ) T cells have the ability to have long-term memory to respond even more quickly to pathogens when they are encountered again in the future.
Keto diet leads to increased presence of immune (γ) T cells and their depletion in adipose tissue
The keto diet tricks the body into burning fat, said study author Dr. Vishwa Deep Dixit of Yale School of Medicine.When the body's glucose levels drop due to the low carbohydrate content of the food, the body acts as if it is in a fasted state, even though it is not, and starts burning fat instead of carbohydrates.
This causes the body to use beta-hydroxybutyric acid (beta-hydroxybutyric acid) to produce ATP and reduces the inflammation caused by NLRP3, a cytoplasmic 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 system cells in adipose tissue drops sharply.As γδ T cells in adipose tissue decline, the level of inflammation previously contained by these cells begins to rise.Inflammation is known to stimulate the accumulation of fat cells.
In addition, mice lacking immune γδ T cells exhibited impaired glucose homeostasis, leading to elevated 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 a 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, the scientists 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 increase.
Side effects of the keto diet
Although the ketogenic diet is safe for healthy people, there may be some initial side effects while your body adjusts to the new diet.
This presentation is often called keto flu and usually ends within a few days.Ketoflu includes low physical energy and reduced mental function, increased hunger, sleep problems, nausea, digestive discomfort and reduced 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 carbs 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 getting 3,000-4,000 mg of sodium (salt), 1,000 mg of potassium, and 300 mg of magnesium per day to reduce side effects.