Is The Ketogenic Diet Safe For Teens

Ketogenic Diet: That's Behind the High Fat Diet

In the ketogenic diet, carbohydrates are avoided, animal products, avocados and lettuce are at the top of the menu.
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The ketogenic diet strictly eliminates carbohydrates. The basic idea: if all the carbohydrate stores are exhausted, fat reserves are broken down. Since the ketogenic diet consumes plenty of fat and hardly any carbohydrates at all, the body remains in the fat metabolism without starvation.

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The ketogenic diet plan: these foods are allowed

The principle of ketosis

The body's cells primarily obtain energy from carbohydrates, above all glucose. When the carbohydrate stores are empty, the body is forced to change its metabolism in order to maintain all important body functions. It gets into the starvation metabolism and taps into fat deposits for energy production. The liver converts the body's own fatty acids into ketone bodies, from which energy is obtained.

Typical symptoms of ketosis

Anyone who opts for a ketogenic diet strives for the ketosis metabolism, in which fat is used instead of carbohydrates for energy. These body signals and tests provide information:

  • Breath: Bad, fruity breath indicates that the ketone acetone is increasingly present in the body and is excreted through the breath. The acetone content can be determined with a special breath test device (breathalyzer).

     
  • Blood test: There are special measuring devices that can detect ketone bodies in the blood. With a small prick like when measuring blood sugar, it can be determined whether and how many ketone bodies are in the blood.

     
  • Urine test: Ketones are also excreted in the urine. The concentration is determined with a test strip.

     
  • Loss of appetite: Many notice that appetite decreases in the ketogenic metabolism.

     
  • Weight loss: Even heavy weight loss can indicate the ketosis metabolism. During the changeover phase, however, the weight loss is usually mainly due to the increased excretion of water.
  • Atkins diet, low-carb or therapeutic fasting - there are many ways to achieve your desired weight. But what are the advantages and disadvantages of these concepts? How can you avoid the yo-yo effect? What works against cravings? Read everything about diet and how to lose weight quickly here.

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Possible benefits of the ketogenic diet

Julia Tulipan, biologist, self-employed nutritionist and expert on low-carbohydrate diets, names possible advantages:

  • Improving insulin sensitivity, i.e. how sensitively the body reacts to the hormone insulin. Insulin sensitivity controls muscle building and fat burning and is of great importance for general health.

  • Reduction of inflammation in the body, as ketone bodies promote apoptosis - the natural cell death. It is important to break down defective cells or cell components.

  • Reducing free radicals that can damage cells, DNA, and arteries. Free radicals are byproducts of converting food into energy. Since less oxygen is involved in the use of fat for energy production, fewer free radicals are produced in the ketogenic metabolism.

  • In many cases, an increase and stabilization of physical and mental performance can be achieved, which for example reduces performance drops in the afternoon.

  • A natural regulation of satiety and feeling of hunger occurs, which prevents cravings.

  • Heavy weight loss due to the ketogenic diet. Also a meta-analysis1 Several studies published in the British Journal of Nutrition in 2013 showed that people on a ketogenic diet can achieve great weight loss over the long term.

Possible disadvantages of the ketogenic diet

However, many people who have tried the strict eating plan also notice disadvantages:

  • Physical complaints, also known as keto flu, are possible during the transition phase. These include mental and physical performance losses, such as extreme tiredness, exhaustion, lack of strength, a reduced energy level and difficulty concentrating. Insomnia, abdominal pain, nausea, constipation (constipation) and diarrhea (diarrhea) can also occur. To help the body change its metabolism, it makes sense to take in more electrolytes. Low-carbohydrate, fresh vegetables help stabilize digestion.

  • The limited menu can promote an undersupply of vitamins and minerals.

  • The high consumption of animal-based foods can (depending on the origin of the products) lead to an increased intake of undesirable accompanying substances such as hormones, antibiotics and accumulated heavy metals that burden the body. In addition, a high proportion of animal fats in the daily menu correlates with the development of diseases that can be influenced by diet, for example of the cardiovascular system, says Bernhauser.

Share of fat, protein and carbohydrates in the energy supply

The following distribution of macronutrients is aimed for in the ketogenic diet:

fat: 70 to 80 percent of the total energy intake
Proteins: 15 percent
carbohydrates: 5 to 10 percent

Nutritionist Tulipan emphasizes that the distribution can be individual. A more recent approach is therefore a "well-formulated ketogenic diet" in which the food selection is not unnecessarily restricted.

  • Fat: When it comes to fat, the quality is crucial. In the ketogenic diet, for example, the focus should be on non-highly processed vegetable fats and good free-range animal fats, says Tulipan. Metabolism expert Bernhauser still criticizes the very high proportion of animal fats in the ketogenic diet, as these are suspected of promoting lifestyle diseases.

  • Proteins: While less radical low-carb diets don't limit protein levels as strictly, that wouldn't work on a ketogenic diet. Because a high protein intake triggers an insulin response in the body that inhibits the formation of ketone bodies, explains Tulipan.

  • Carbohydrates: The ketogenic diet is not a "zero carbohydrate diet" either. But even if you wanted to take it to the extreme, the body could produce glucose endogenously: "Fatty acids are stored in the form of triglycerides and their breakdown releases glycerol, which is used for energy production in gluconeogenesis - a metabolic pathway in which glucose is not -Carbohydrate precursors are formed - can be introduced, "says Tulipan.

Tulipan explains that the general recommendations of the DGE to eat unprocessed, fresh and nutrient-rich foods as far as possible should also be applied to the ketogenic diet - regardless of the distribution of the main energy suppliers.

Ketogenic Diet: Which Foods Are Allowed?

High calorie foods high in fat and protein are high on the list of desirable foods:

  • flesh

  • fish and seafood

  • Eggs

  • Milk, cheese and other dairy products

  • Nuts and seeds

  • Low-carb vegetables like tomatoes, cauliflower, green vegetables like spinach, and broccoli

  • Low-carb fruits like berries, lemons, limes, kiwi and avocado

  • Mushrooms

Foods To Avoid On The Keto Diet

  • Grains such as rice, wheat, rye, corn or oats

  • Cereal products such as baked goods, muesli, pasta, chips

  • Carbohydrate-rich tuber and root vegetables such as parsnips, potatoes, carrots

  • legumes

  • Carbohydrate-rich fruits such as bananas, grapes, figs, pomegranates, persimmons

  • Sweeteners such as sugar, agave syrup, honey

  • Ready-made products, as these usually also contain a lot of carbohydrates

  • Dried fruits, because they are rich in fructose

  • sugared dairy products

  • Fruit juices and sugared drinks

  • alcoholic drinks

  • sugary sauces and dips such as ketchup or salad dressing

Lose weight with a ketogenic diet

What is special about the ketogenic diet is that it does not work through an artificial calorie restriction, but rather a hormonal path in which the insulin level is kept constant and relatively low. This promotes the release of fat. "Due to the more stable blood sugar, the body does not get into the blood sugar roller coaster, which also naturally regulates hunger and satiety and prevents cravings," says nutritionist Tulipan.


Other nutrition experts advocate less radical dietary changes: "In my opinion, sustainable weight loss cannot be achieved successfully with a short-term, radical diet," says nutritionist Isabel Bernhauser. In order to lose weight successfully in the long term, it would rather be a long-term change in diet that supports the metabolism and is tailored to the needs of the person concerned.

Who Is The Ketogenic Diet Not For?

The strict nutrition plan can be dangerous with various diseases. These include:

  • Type 1 diabetes
  • certain diseases of the pancreas
  • Metabolic disorders
  • Renal failure
  • severe liver disease

In addition, there are currently no reliable studies on the ketogenic diet during pregnancy and breastfeeding. The long-term consequences of a persistent state of ketosis on the body have not yet been adequately researched either.

In any case, a strict, ketogenic diet should only be tackled by healthy people in consultation with an experienced doctor and nutritionist.

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Follow a strict ketogenic diet over the long term?

Many people are also considering the ketogenic diet as a long-term diet. However, there is no reason for a healthy person to follow a ketogenic diet for years and the strict nutrition plan can hardly be adhered to in everyday life.

"In reality, after a transition phase, you usually fluctuate back and forth and cyclically between strictly ketogenic and somewhat relaxed phases, which is actually the more natural approach," says Tulipan. The goal is rather a so-called "metabolic flexibility", which describes the original state of a healthy cell, through which the body generally gets back into fat metabolism more quickly.

Criticism of the ketogenic diet

The extremely low-carbohydrate form of nutrition is controversial among nutrition experts, as the choice of food is severely restricted, which can lead to nutrient deficiencies. "In addition, our organism, and in particular the brain, prefer carbohydrates - whereby full-fledged sources instead of refined sugar - are the primary sources of energy," says Isabel Bernhauser. The brain could also function with ketone bodies, but it would take more effort to produce them and to design the metabolism accordingly.

Carbohydrate restriction must be compensated for on a ketogenic diet plan with sources of fat and protein. Since vegetable foods predominantly have too high a carbohydrate content, animal foods are often used primarily. However, a high proportion of animal fats correlates with the development of lifestyle diseases such as atherosclerosis, cardiovascular or rheumatic diseases, says Bernhauser. Food of animal origin also often contains undesirable accompanying substances such as hormones, antibiotics and accumulated heavy metals, as animals are further down the food chain. "This is one of the reasons why, from my point of view, a ketogenic diet is not recommended in the long term," says Bernhauser.

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Ketogenic diet as a form of therapy

The ketogenic diet is also occasionally used to treat illnesses. Switching to a ketogenic diet as a therapy should generally only take place under medical supervision.

Childhood epilepsy and brain metabolic disorders

A strictly medically controlled ketogenic diet can be used for treatment-resistant epilepsy in childhood. This must be initiated and monitored by doctors and nutrition experts with good metabolic knowledge. The strictly controlled eating plan requires a high level of discipline from both children and parents as it involves weighing the foods, adhering to the reduced food choices and measuring ketones on a daily basis. The goal is to maintain controlled ketosis.

The ketogenic diet can also be used for disorders of the brain's energy metabolism - such as a pyruvate dehydrogenase deficiency - to provide ketone bodies as an alternative source of energy.

The energy metabolism is also disturbed in the case of hereditary diseases such as the GLUT-1 deficit syndrome. The inadequate transport of glucose from the blood to the brain leads to a lack of energy that can possibly be compensated for with a ketogenic diet.

Special diet for cancer

Many scientists are researching the impact of a ketogenic diet on cancer. It is designed to help cancer patients slow the progression of their disease and cope better with chemotherapy. The keto diet strengthens healthy cells, at the same time it slows tumor cells that have a strong "sugar hunger" on a reduction diet.

As far as is known up to now, this form of nutrition mainly benefits patients in whom the tumor is growing rapidly, i.e. the cancer is particularly aggressive and "sugar-hungry". "We observe in patients that the cancer can even come to a standstill," says Kämmerer.

One major difficulty, however, is that a ketogenic diet is a whole-or-not-at-all solution: "If patients save just a little bit of carbohydrates, they get hungry, feel weak and lose weight," warns Ulrike Kämmerer against half-hearted self-experiments . "If cancer patients want, they can also stick to the Atkins diet," suggests the expert.

It is not yet known whether the ketogenic diet can really have a beneficial effect on cancer. This would require further, large-scale long-term studies. Despite isolated positive experiences in the use against cancer, the concept of the ketogenic diet is not yet officially recommended.