A ketogenic diet (keto diet) contains approximately 90-99% of calories from fat and protein and only 1-10% from carbohydrates.Eating this way may provide some benefits for weight loss or reducing the number of epileptic seizures.
However, a new study has found that following a 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 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, and is very similar 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 fats into fatty acids and ketone bodies.
Ketosis occurs when the amount of ketone bodies in the body increases, 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 shows some beneficial benefits for the body along with increased ketone levels.
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 diet group or a low-carb diet group.The low-fat diet group was calorie restricted.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 the human groups.
Of note, the low-carb (keto diet) group had higher blood levels of triglycerides and HDL, but other biomarkers were similar between groups.
If we analyze the 23 known human clinical studies evaluating the effects of low-carbohydrate diets (keto diets), we can summarize the results of these studies.Most studies achieved 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 result in 2-3 times more weight loss than low-fat diets.In some cases there was no significant difference.
- For the most part, the low-fat group was calorie restricted, while the low-carb group could eat as much as they wanted.
- When all subject groups restricted calories, the low-carbohydrate diets 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 early.People then start to put the weight back on over time and after coming 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 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 way of eating.This results in 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 in the short term (up to 12 months) by reducing the risk of developing type 2 diabetes and ultimately reducing the inflammation caused by fat cells.
A Yale University study found that the positive and negative effects of diet are related to the behavior of tissue-specific immune cells called gamma delta T cells (γδ T cells), which reduce the risk of diabetes and inflammation.
Gamma delta T cells are immune T cells with a distinct 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 one γ (gamma) chain and one δ (delta) chain.This group of T cells is less common than αβ T cells—about 4–10% of all 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 borders of the more evolved primitive innate immune system, which responds rapidly to various 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 long-term memory to respond more quickly to pathogens when they are re-encountered in the future.
A keto diet causes an increase in immune (γδ) T cells and their depletion in adipose tissue.
Study author Dr. from Yale School of Medicine.Vishwa Deep Dixit keto diet induces the body to burn fat.When the glucose level in the body decreases because the food contains few carbohydrates, the body behaves as if it is fasting, even if it is not, it starts burning 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 are spread throughout the body.And the number of these protective immune cells in adipose tissue is drastically reduced.As γδ T cells decrease in adipose tissue, the level of inflammation previously contained by these cells begins to increase.Inflammation is known to stimulate the accumulation of fat cells.
Furthermore, mice lacking immune γδ T cells showed impaired glucose homeostasis leading to increased blood glucose levels.
According to scientists, the keto diet reduces the risk of diabetes and inflammation, and also improves the body's metabolism.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 at the same time as its breakdown, 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 the symptoms 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 as 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 includes low body energy and impaired mental function, increased hunger, sleep problems, nausea, digestive discomfort, and decreased performance during exercise.
To minimize this, you can start a low-carb diet in the first 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 mineral supplements can help.Try to get 3000-4000 mg of sodium (salt), 1000 mg of potassium and 300 mg of magnesium per day to reduce side effects.