A ketogenic diet (keto diet) contains approximately 90-99% of calories from fat and protein and only 1-10% from carbohydrates.Eating like this may have some benefits in terms of weight loss or reducing the number of epileptic seizures.
However, a new study found that the keto diet only provides health benefits 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 be beneficial 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 shares many similarities with the Atkins diet and the low-carb diet.Following the diet leads to a sharp reduction in carbohydrates and replaces them with fats and proteins.This greatly reduces the body's use of carbohydrates and uses fat as its main source of energy.When there is little glucose in the body, the liver processes fat into fatty acids and ketone bodies.
When the amount of ketone bodies increases in the body, ketosis occurs and the brain begins to use these ketone bodies instead of carbohydrates.When this happens, the body is incredibly efficient at burning fat for energy.
A ketogenic diet can significantly lower blood sugar and insulin levels.This, combined with the increased amount of ketones, has a beneficial effect on 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: a low-fat diet group or a low-carb diet group.People on a low-fat diet were calorie restricted.This study lasted 12 months.
The low-carb group lost more weight, 7.3% of their total body weight, than the low-fat group, which lost 4.5%.The difference was statistically significant at months 3 and 6, but not at month 12.At the end of the experiment, there was no weight difference between the groups of people.
It is worth noting that blood levels of triglycerides and HDL increased in the low-carbohydrate (keto diet) group, but other biomarkers were similar between groups.
If we analyze the known 23 human clinical studies examining 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).
A few other factors to note:
- 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, the low-fat groups were restricted in calories, while the low-carb groups were allowed to eat as much as they wanted.
- When all groups of subjects restricted calories, the low-carb diets still showed greater weight loss, although this was not always significant.
- In one study, 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.Over time and after quitting the keto diet, people start to put the weight back on.
- When scientists looked at belly fat (bad visceral fat), low-carb diets showed a clear advantage in reducing this type of fat.
Two 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 effect 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 in the short term (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 at Yale University showed that the positive and negative effects of diet are linked to the behavior of immune cells called gamma delta T cells (γδ T cells), which are 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 whose TCR consists 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 is generally 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 many features that lie 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 activities much more slowly.At the same time, (γδ) T cells are able to have long-term memory to respond even more quickly to pathogens when they are re-encountered in the future.
The keto diet leads to increased presence and depletion of immune system (γδ) T cells in adipose tissue
According to Dr. Vishwa Deep Dixit, a researcher at the Yale School of Medicine, the keto diet tricks the body into burning fat.When the body's glucose levels drop due to the low carbohydrate content of the food, the body behaves as if it is in a state of starvation, when it is not, and begins to burn fat instead of carbohydrates.
This prompts 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.
In turn, the process of reducing carbohydrates in food 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 sharply reduced.As γδ T cells in adipose tissue decline, the level of inflammation that these cells previously harbored begins to increase.Inflammation is known to stimulate the accumulation of fat cells.
In addition, mice lacking immune γδ T cells showed impaired glucose homeostasis, leading to increased blood glucose levels.
The keto diet reduces the risk of diabetes and inflammation, and improves the body's metabolism, the scientists noted.After a week on the keto diet, the mice showed reduced blood sugar and inflammation.
But if the body is in this "hunger-not-hunger" mode for a long enough time (more than 1-2 weeks), the accumulation of fat occurs simultaneously with its breakdown, the scientists concluded.When the mice continued to eat a high-fat, low-carbohydrate diet, they consumed more fat than their bodies could burn.Then the signs of diabetes and obesity began to increase.
Keto Diet Side Effects
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 referred to as the keto flu and usually ends within a few days.Keto flu means low body energy and reduced mental function, increased hunger, sleep problems, nausea, digestive discomfort and reduced performance during exercise.
In order to minimize this, you can start a low-carbohydrate diet in the first few weeks.This trains 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 can help.To reduce side effects, try taking 3,000-4,000 mg of sodium (salt), 1,000 mg of potassium, and 300 mg of magnesium per day.