The ketogenic diet (keto diet) contains about 90-99% of calories from fat and protein and only 1-10% from carbohydrates.Such a diet may provide some benefits in weight loss or reducing the number of epileptic seizures.
However, as a new study has found, following the keto diet only provides health benefits 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.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%) and high-fat diet that shares many similarities with the Atkins diet and the low-carb diet.Compliance with this diet leads to a sharp reduction in carbohydrates and their replacement with fats and proteins.This significantly reduces the body's consumption of carbohydrates and switches to using fat as the main source of energy.If there is little glucose in the body, the liver converts 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 reduce blood sugar and insulin levels.This, coupled with the increased amount of ketones, shows some positive benefits for the body.
However, the keto diet can be potentially dangerous for people with type 1 diabetes.
Benefits of the Keto Diet
In a study of 63 people, two groups were formed: either a low-fat diet group or a low-carbohydrate diet group.The group of people on a low-fat diet was low in calories.This study lasted 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 groups of people.
It is worth noting that the low-carb diet (keto diet) group had elevated blood levels of triglycerides and HDL, but other biomarkers were similar between groups.
If we analyze the known 23 human clinical studies that examined the effects 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 to consider:
- Low-carb diets often resulted in two to three times more weight loss than low-fat diets.In some cases there was no significant difference.
- In most cases, calories in the low-fat groups were restricted while the low-carb groups were allowed to eat as much as they wanted.
- Even though all test groups restricted their calorie intake, there were still greater reductions in body weight with the low-carb diet, although these were 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 early on.Over time and after stopping the keto diet, people then gain weight again.
- When scientists examined the amount of belly fat (bad visceral fat), low-carb diets showed a clear benefit 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 foods and the appetite-stimulating effects of this diet.This leads to a drastic 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 thereby 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 the characteristic 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 T cells (γδ) have a TCR consisting of a γ chain (gamma) and a δ chain (delta).This group of T cells tends to be less abundant (approximately 4–10% of all T cells) than αβ T cells, but has the highest frequency in the intestinal mucosa within a lymphocyte population known as intraepithelial lymphocytes (IELs).
Gamma delta immune T cells are characterized by a number of properties that place them within the confines of the more evolutionarily primitive innate immune system, which allows a rapid response to a variety of pathogens, and the adaptive immune system, in which lymphocytes coordinate their actions much more slowly.At the same time, (γδ) T cells have the ability to have a long-term memory so that they can react even faster if they encounter pathogens again.
A keto diet leads to an increased presence of immune T cells (γδ) and their breakdown in fatty tissue
The keto diet causes the body to burn fat, said study author Dr.Vishwa Deep Dixit from Yale School of Medicine.When the body's glucose levels drop due to low carbohydrate content in the diet, the body behaves as if it were in a fasting state, even if it is not, and begins to burn fats 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 carbohydrates in food in turn creates ketone bodies (ketones) as an alternative energy 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 fatty tissue decreases sharply.As γδ T cells decrease in adipose tissue, 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 immune γδ T cells exhibited impaired glucose homeostasis, resulting in 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, mice showed reduced blood sugar and inflammation.
But when the body is in this “hunger-not-starve” mode for a sufficiently long period of time (more than 1-2 weeks), fat accumulation occurs simultaneously with fat loss, scientists have found.When the mice continued to eat a high-fat, low-carb diet, they consumed more fat than their bodies could burn.And then 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 as your body adjusts to the new diet.
This phenomenon is often referred to as the keto flu and usually ends within a few days.Keto flu includes low body energy and impaired mental function, increased hunger, sleep problems, nausea, indigestion, and reduced exercise performance.
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 completely eliminating 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 may help.Try taking 3,000-4,000 mg of sodium (salt), 1,000 mg of potassium, and 300 mg of magnesium daily to reduce side effects.