What is keto asidosis

Ketogenic Diet (Keto diet)

The ketogenic diet is a form of nutrition that is very high in fat and low in carbohydrates, through which the body adjusts itself to a non-energy-deficient starvation metabolism and increases ketone bodies in the liver. The ketogenic diet is mainly used to treat drug-resistant epilepsy in children and adolescents.

Short version:

  • With the ketogenic diet, low-carbohydrate food intake leads to a kind of starvation in the body, but there is no energy deficit, as is the case with fasting.
  • The metabolism gradually changes and finally comes into what is known as ketosis.
  • Ketosis occurs when the body runs out of carbohydrates and therefore no longer has any glucose available for energy production and instead burns a glucose substitute - the ketone bodies that are formed in the liver.

The diet is already being used successfully as an additional therapy for epilepsy in children and adolescents, which are difficult to treat with medication. More recent studies also suggest that therapeutic success in Alzheimer's disease is possible. A non-medical form of the ketogenic diet are so-called low carb diets (e.g. Atkins diet). They are mainly used for weight loss.

How does our metabolism work?

Metabolism describes all (chemical) processes that take place within our body cells and control vital processes in our body. These include, for example, sleep, wakefulness, growth, muscle building, breathing and much more. So that our metabolism works and our body functions can run smoothly, our body needs nutrients and energy, which it converts or breaks down into enzymes and hormones, but also excretion products and toxins.

Our body gets the energy for this conversion and dismantling work from the nutrients that we supply with food. The main energy suppliers include

which our body converts in the stomach and intestines into glucose (simple sugar), fatty acids and amino acids and transfers them into the blood.

How does ketosis arise?

Normally, our body gets a large part of the energy it needs from carbohydrates, which are broken down into glucose and then used to generate energy. If not enough carbohydrates are consumed, the metabolism - as is the case with fasting, for example - changes to a starvation metabolism (catabolism) after a few days, in which the body supplies itself with energy.

The body draws on its own glucose stores and converts its fat reserves in the liver into a compound of molecules - the ketone bodies. The ketone bodies formed serve as a glucose substitute, so to speak, in order to provide enough energy - especially for the brain. This physiological process is called ketosis or ketolysis (hence the "ketogenic diet").

For which diseases is the ketogenic diet used?

The ketogenic diet is used as an additional therapy, especially in children and adolescents with certain forms of epilepsy, for whom (more than two) drugs for epilepsy treatment have so far not had an adequate effect.

It has been observed that ketosis can significantly reduce the frequency and severity of epilepsy attacks if the cause of the attacks is hypoglycaemia in the brain. Because ketone bodies contain more energy and "burn" more slowly than glucose, hypoglycaemia occurs less quickly. This also means that seizures occur less often, so the assumption. However, the exact mechanism has not yet been clarified.

Ketogenic diets are also used successfully for rare defects in energy metabolism, such as the GLUT 1 defect and pyruvate dehydrogenase deficiency.

Promising therapeutic results could also be observed in the following diseases:

  • Rett Syndrome
  • Landau-Kleffner Syndrome
  • Ohtahara syndrome

According to preliminary studies, a ketogenic diet should also have a positive effect on Alzheimer's disease or strokes. Further studies are currently investigating the effect of the ketogenic diet on cancer. There is the hypothesis that the ketogenic diet can "starve" tumor cells.

According to this, cancer cells are supposed to feed primarily on the sugar hormone insulin, which is increasingly released when eating bread, pasta and sugar. The ketogenic diet could - so the hypothesis - throttle the supply valve for the cancer cells. How the low-carbohydrate diet influences disease states has not yet been conclusively explained or proven in any of these cases.

Who is the ketogenic diet used with?

The ketogenic diet is used primarily in children and adolescents as an additional therapeutic measure under strict medical supervision. Infants can also be treated on a ketogenic diet.

Experience has shown that the diet seems to lose its effectiveness in children older than 8 to 12 years and is also more difficult to follow because of the diet that takes getting used to. In adults, the ketogenic diet is rarely used for treatment and has therefore been little researched.

How is the keto diet carried out?

The diet is carried out under medical nutritional supervision and should be initiated as an inpatient (approx. 5-7 days) in a hospital or a suitable institution. Complications such as digestive problems caused by metabolic changes can be treated quickly.

The inpatient stay also means that the patient and his relatives can be better trained and looked after in dealing with the ketogenic diet. The training is usually carried out by specially trained dieticians or dietitians and provides, among other things, the following content:

  • suitable foods for the ketogenic diet
  • Preparation of "ketogenic", i.e. high-fat foods
  • Control measurement of ketones in urine and blood
  • Dealing with diet mistakes

A ketogenic diet must be strictly and carefully followed in order to achieve the desired effects. Well-functioning cooperation between the patient, parents or relatives, doctors and dieticians is also essential for the success of the therapy and can only be optimally achieved in a team. During the diet, the patient's condition must be monitored regularly, even after discharge from the hospital.

It is also essential to measure blood lipid levels - such as total cholesterol (Chol), triglycerides (TG), LDL cholesterol and HDL cholesterol, as negative influences on fat metabolism have been described. In addition, the urine and blood ketosis values ​​- similar to a blood sugar control - must be measured or monitored using test strips and a measuring device, as well as the patient's blood gases.

After about two to three months of consistent diet, the effectiveness of ketosis in the body can be assessed. Medicines for the treatment of epilepsy in children and adolescents are therefore usually continued to be taken when the diet is initiated and only slowly reduced when successful.

How is the ketogenic diet structured?

With the ketogenic diet, carbohydrates that are contained in bread, pasta, potatoes or sugar, for example, are greatly reduced. At the same time, the absorption of fats from meat, fish and healthy oils is greatly increased. Over time, the body switches to a kind of starvation metabolism, produces more ketone bodies and goes into ketosis.

Before starting any ketogenic diet, it is important to determine or calculate the exact energy and protein requirements (depending on age and energy expenditure) of the patient in order to be able to adapt the diet or nutrition plan individually. To do this, the exact weight ratio - the "ketogenic ratio" - of fat to carbohydrates and proteins is calculated.

For example, a ketogenic ratio of 4: 1 means that the food consumed must consist of 80% fats in total. Depending on age, the remaining 20% ​​must contain the required amount of proteins. The proportion of carbohydrates is thereby reduced to a minimum and thus enables effective ketosis to be maintained in the body. Multivitamins, minerals and trace elements such as calcium are also taken in the form of carbohydrate-free preparations in order to avoid deficiencies.

What side effects can I experience with the keto diet?

In general, there are hardly any or easily treatable side effects on a ketogenic diet. During the metabolic changeover phase, hypoglycaemia (blood sugar levels <50 mg / dl), diarrhea, vomiting and / or refusal to eat can occur. Especially in the first few weeks of changing your diet, you may feel more tired.

The most common problem, however, is diet errors (e.g. caused by "hidden" sugar in toothpaste, cough syrup, etc.). They can lead to the loss of ketosis and thus trigger seizures. Even with infections that are accompanied by fever and vomiting, a lack of fluids can lead to acidosis (disturbance of the acid-base balance). Sometimes people also experience constipation, kidney stones, or hypercholesterolemia.

The long-term side effects of the ketogenic diet have not yet been adequately studied. However, there is some evidence that growth may be impaired in children and adolescents.

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Tanja Unterberger
Medical review:
Univ. Prof. Dr. Kurt Widhalm
Editorial editing:
Katrin Derler, BA

Status of medical information:

S1 guideline of the Society for Neuropediatrics: Ketogenic Diets; http://www.awmf.org/uploads/tx_szleitlinien/022-021l_S1_Ketogene_Di%C3%A4ten_2014-04.pdf (last accessed: 15.03.2017)

Hall KD, Chen KY, Guo J, Lam YY, Leibel RL, Mayer LE, Reitman ML, Rosenbaum M, Smith SR, Walsh BT, Ravussin E. Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. American Journal of Clinical Nutrition 2016; 104: 324-33

Bostock ECS, Kirkby KC, Taylor BVM. The current status of the ketogenic diet in psychiatry. Frontiers in Psychiatry 2017; 8: 43: 1-10

Ashrafi MR, Hosseini SA, Zamani GR, Mohammadi M, Tavassoli A, Badv RS, Heidari M, Karimi P, Malamiri RA. The efficacy of the ketogenic diet in infants and young children with refractory epilepsies using a formula-based powder. Acta Neurol Belg 2017; 117 (1): 175-82

Van der Louw E, Van den Hurk D, Neal E, Leiendecker B, Fitzsimmon G, Dority L, Thompson L, Marchió M, Dudzinska M, Dressler A, Klepper J, Auvin S, Cross JH. Ketogenic diet guidelines for infants with refractory epilepsy. European Journal of Pediatric Neurology 2016; 20 (6): 798-809

Schoeler NE, Corss JH. Ketogenic dietary therapies in adults with epilepsy: a practical guide. Practical Neurology 2016; 16 (3): 208-14

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