The keto diet carries some possible side effects. Especially the risk of hyperacidity of the blood should be considered. But other health side effects should not be underestimated. Nevertheless, the ketogenic diet also holds a not inconsiderable benefit for medicine in certain areas. Which side effects can occur with the keto diet and with which diseases one can benefit from the dietary form, you can read below.
Risks of a ketogenic diet
The most serious possible side effect, as already indicated, is the risk of ketoacidosis. This is an overacidification of the blood by ketone bodies and can bring health damage. Consequences of overacidified blood may include:
- A drop in performance
- Fatigue and listlessness
- Bad breath
- Nausea and indigestion
- Irregular heartbeat
- A rising uric acid level and thus an increased risk of gout or kidney stones
Also, due to the restricted diet, there may be a risk of a possible undersupply of important nutrients. To note in the keto diet is also the high risk of the yo-yo effect, that is, a rapid weight gain after the termination of the diet.
What is the keto flu?
Another possible side effect is the so-called keto flu. This can occur while the metabolism is changing to ketosis. Symptoms of keto flu include:
- Lack of energy and fatigue
- Weakness
- Headache
- Difficulty concentrating
- Cravings
- Constipation
The above symptoms usually disappear after a few weeks.
Ketogenic diet in medicine
The keto diet is used in certain diseases under medical supervision to support therapy. This is the case, for example, in rare, congenital metabolic diseases or epilepsy. In the case of glucose transporter (Glut1) deficiency – a metabolic disease in which the body cannot transport or utilize glucose – the keto diet is even the therapy of choice. This is because ketone bodies serve as an alternative energy source here. In the following, you will get an overview of the diseases for which the keto diet may have a positive influence. However, you should always keep in mind that the keto diet is not a medically recognized therapy method. Therefore, in case of illness, you should consult the diet with a doctor under all circumstances.
The ketogenic diet for epilepsy
Various studies indicate that a ketogenic diet for epilepsy can reduce or even completely prevent the occurrence of seizures in children and adolescents who do not respond to antiepileptic drugs. This is said to be especially true for a vegetarian ketogenic diet. Other studies also suggest that the keto diet is effective in adults with epilepsy. Why the ketogenic diet may reduce epileptic seizures is still unclear. Some researchers suggest that the metabolic change alters the gut flora and has an anticonvulsant effect. Other scientists assume that neurotransmitters are regulated by the ketone bodies. Scientifically researched and medically applied is the Keto Diät with epilepsy particularly in America. In Germany, however, the ketogenic diet is rather rarely used for the therapy of epilepsy, because it is difficult to implement, especially in children.
Ketogenic diet: diabetes and obesity
The keto diet is also said to have a positive effect on diabetes. Scientific studies have shown, especially for type 2 diabetes, that a ketogenic diet can reduce and maintain constant blood glucose levels and improve insulin sensitivity. Insulin doses as well as the risk for complications could be lowered and thereby. On the other hand, consumer centers warn against insulin resistance brought about by a ketogenic diet. Since by the metabolic change with the Keto Diät the fat burn is driven, the insulin mirror is held low and a faster saturation feeling occurs, the nourishing form can be used also with predominance. A ketogenic diet is also said to be able to help with lipedema.
The keto diet and neurological disease
Research is providing increasing evidence that a ketogenic diet may be able to support therapy for neurological diseases of the brain. These include Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis, among others. These diseases likely have impaired glucose uptake and utilization in common. However, the study results to date are not representative, as they are based either on studies in animals or with very few study participants. In any case, individualized and physician-controlled therapy is necessary for all of the diseases mentioned – the additional use of the keto diet should always be discussed with the physician.
Keto diet and cardiovascular diseases.
Some studies, such as the study by Paoli et al. published in 2013, found improvements in body fat, blood pressure, blood glucose, and cholesterol levels in the course of a ketogenic diet. Thus also the risk for kardiovaskuläre illnesses could lower. German consumer groups, on the other hand, warn that the keto diet could result in cardiovascular disease. The findings of such studies as the above should therefore be evaluated with caution, as long as there are not yet sufficient studies for reliable statements – especially long-term studies are lacking so far.
Does a ketogenic diet help with cancer?
There is also scientific discussion about whether the keto diet can slow down the growth of cancer cells. This is based on the assumption that tumor cells can hardly process saturated fatty acids. While some studies point to an effectiveness, other studies could not confirm this effect and criticize the lack of high-quality studies. In addition, it must be borne in mind that cancer cells are highly adaptable and are therefore unlikely to be eliminated by diet. However, as a supportive element in cancer therapy, the ketogenic diet may possibly play a role.
The keto diet in sports
In addition to medical patients, some athletes are said to benefit from the ketogenic diet: It is supposed to improve performance and help lose weight quickly before a competition, for example. However, this has not been scientifically proven. Strength athletes often eat a ketogenic diet for optical reasons. This is because the keto diet dehydrates the body, making muscles stand out more. For endurance athletes such as runners or climbers, the ketogenic diet is not suitable. This is because this group of athletes needs sufficient glucose due to the sustained athletic stress – and for this it needs carbohydrates.
Who is the keto diet not suitable for?
A ketogenic diet is not suitable for everyone, because some groups of people can suffer serious harm and should therefore rather refrain from the low-carbohydrate and high-fat diet. These groups of people include those with
- Elevated blood lipid levels: if one suffers from hyperlipidemia (elevated cholesterol, triglyceride and lipoprotein levels), the organism cannot break down fat properly, which is why a high-fat diet can become a problem.
- Heart disease such as heart failure: if the body has to switch to a metabolism with ketone bodies instead of glucose, this can put additional strain on a weakened heart.
- Bile problems, for example, gallstones or a removed gallbladder: fat digestion is more difficult in people with diseased or absent gall bladder, so a high-fat diet would be counterproductive.
- Liver or kidney disease: A ketogenic diet can put additional strain on the liver and kidneys, as it deprives the body of water, but at the same time provides it with plenty of fat to break down.
- Underweight or an eating disorder: those affected are already struggling with a lack of nutrients anyway and also have to gain weight instead of lose.
Who wants to try the keto diet despite one of these diseases, should not do so under any circumstances without medical advice.
Ketogenic diet during pregnancy
There are no scientific studies on this topic so far. However, in order to be able to ensure the normal development of the baby, pregnant women are generally advised not to follow any kind of diet and instead to eat a balanced diet. This includes the consumption of carbohydrates.
Conclusion: Is a ketogenic diet healthy?
For people with diseases such as epilepsy, a keto diet may well have health benefits. Also a rapid weight loss can be achieved with this diet. But consumer advocacy groups warn that the keto diet may be deficient in vitamins, fiber and phytochemicals. In addition, the organizations point out that a ketogenic diet can lead to the development of cardiovascular diseases or insulin resistance in the long term. In addition, the ketogenic diet contradicts long-established nutritional guidelines. For example, the German Nutrition Society (DGE) recommends generating only 30 to 35 percent of daily energy from fats. The keto diet should therefore only be used, if at all, under medical supervision and, if necessary, with the help of a nutritionist. Anyone who wants to lose weight in the long term and without a yo-yo effect had better make their diet balanced and healthy, and exercise regularly.
