A ketogenic diet (keto diet) contains approximately 90-99% of calories from fat and protein and only 1-10% from carbohydrates.This way of eating can bring some benefits for weight loss or reducing the number of epileptic seizures.
However, as new research has shown, the keto diet brings health benefits only for a short period of time - 1-2 weeks - after which the 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.The ketogenic diet 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 and low-carb diets.Following this diet leads to a sudden reduction of 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 fats 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.
A ketogenic diet can significantly lower blood glucose and insulin levels.This, along 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
One study of 63 people created two groups: either a low-fat group or a low-carb group.A 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.
It is worth noting that the low-carbohydrate (keto diet) group had elevated levels of triglycerides and HDL in the blood, 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 greater 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 were allowed to eat as much as they wanted.
- When all subjects' groups restricted their calorie intake, the low-carbohydrate dieters still showed a greater reduction 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 greatest in the early stages.People then start to put the weight back on over time and after they leave the keto diet.
- When scientists looked at the amount of abdominal fat (the bad visceral fat), a low-carb diet had a clear advantage in reducing this type of fat.
The two main reasons 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 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 linked 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 a characteristic 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) TCR chains.In contrast, gamma delta (γδ) T cells have a TCR consisting of one γ (gamma) chain and one 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 is most abundant in the intestinal mucosa, within a population of lymphocytes known as intraepithelial lymphocytes (IEL).
Gamma-delta immune T cells are characterized by numerous features that place them within the limits of the evolutionarily more primitive innate immune system, which provides a rapid response to various pathogens, and the adaptive immune system, where lymphocytes coordinate their actions much more slowly.At the same time, (γδ) T cells have the ability of long-term memory to respond even more quickly to pathogens when they are encountered again in the future.
The keto diet leads to an increased presence of immune (γδ) 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 the Yale School of Medicine.When the body's glucose level decreases due to the low carbohydrate content of the food, the body acts as if it is fasting, 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 reduce inflammation mediated by NLRP3, a cytosolic protein involved in the activation of the inflammatory interleukins IL-1b and IL-18.
The process of reducing the 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 drops sharply.As γδ T cells in adipose tissue decrease, the level of inflammation that these cells previously harbored begins to rise.Inflammation is known to stimulate the accumulation of fat cells.
Moreover, mice lacking immune γδ T cells exhibited impaired glucose homeostasis, leading to increased blood glucose levels.
Keto diet reduces the risk of diabetes and inflammation, and improves metabolism in the body, scientists point out.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" regime for long enough (more than 1-2 weeks), scientists have discovered that fat accumulates at the same time as it breaks down.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 started to increase.
Keto diet side effects
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 referred to as 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 discomfort and reduced performance during exercise.
To minimize this, you can start with 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 the balance of water and minerals in your body, so adding salt to your meals or taking mineral supplements can help.Try taking 3,000-4,000 mg of sodium (salt), 1,000 mg of potassium, and 300 mg of magnesium per day to reduce side effects.