The ketogenic diet: risks and benefits

The keto diet comes with some potential side effects. In particular, the risk of  hyperacidity  in the blood must be taken into account. But other health side effects should not be underestimated. Nevertheless, the ketogenic diet also has significant medical benefits in certain areas. Below you can read about the side effects that can occur with the keto diet and which diseases can benefit from the diet.

Risks of a ketogenic diet

The most serious possible side effect, as already indicated, is the risk of  ketoacidosis .  This is acidification of the blood by ketone bodies and can be harmful to health. Consequences of acidic blood can include:

• a drop in performance
• tiredness and sluggishness
• bad breath
• nausea  and indigestion
• irregular heartbeat
• a rising uric acid level and thus an increased risk of  gout  or kidney stones

Due to the restricted diet, there may also be a risk of a possible  undersupply  of important nutrients.

Another thing to keep in mind with the keto diet is the high risk of the  yo-yo effect,  i.e. rapid weight gain after the end of the diet.

What is the keto flu?

Another possible side effect is the so-called keto flu. This can occur while the  metabolism  switches to ketosis.

Symptoms of keto flu include:

• lack of energy and tiredness
• weakness
• headache
• difficulty concentrating
• cravings
• constipation

The symptoms mentioned usually disappear after a few weeks.

Ketogenic diet in medicine

The keto diet is used under medical supervision to support therapy for certain medical conditions. This is the case, for example, with rare, congenital metabolic diseases or  epilepsy  .

In the case of glucose transporter (Glut1) defect – a metabolic disease in which the body cannot transport or utilize glucose – the keto diet is even the therapy of choice. Because ketone bodies serve as an alternative source of energy.

The following is an overview of the diseases that the keto diet may have a positive impact on.

However, one should always keep in mind that the keto diet is not a medically recognized therapy method. Therefore, in the event of illness, you should always  discuss the diet with a doctor.

The ketogenic diet in epilepsy

Various studies ^1,2  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 should especially apply to a vegetarian ketogenic diet. Additional studies ^3,4  also suggest the effectiveness of the keto diet in adults with epilepsy.

Why the ketogenic diet can reduce epileptic seizures is still unclear. Some researchers suspect that the change in metabolism changes the  intestinal flora  and has an antispasmodic effect. ⁵  Other scientists hypothesize that neurotransmitters are regulated by ketone bodies. ⁶

The keto diet for epilepsy has been scientifically researched and medically applied primarily in America. In Germany, however, the ketogenic diet is rarely used to  treat epilepsy  , as it is difficult to implement, especially in children. ⁷

Ketogenic Diet: Diabetes and Obesity

The keto diet is also said to have positive effects on  diabetes  . Scientific studies ^6,8,9,10  have shown, especially for type 2 diabetes, that a ketogenic diet  can reduce and maintain blood sugar levels  and improve insulin sensitivity. Insulin doses and the risk of complications could and will be reduced as a result.

On the other hand, consumer advice centers warn of insulin resistance caused by ketogenic nutrition.

Since the metabolic change in the keto diet drives fat burning, insulin levels are kept low and a feeling of satiety occurs more quickly, the diet can also be used if you are overweight. ^6,11,12  A ketogenic diet is  also said to be able to help with  lipoedema .

The keto diet and neurological disorders

Research is providing increasing evidence ^9,13  that a ketogenic diet may support the therapy of neurological disorders of the brain. These include  Alzheimer’s, Parkinson’s and  multiple sclerosis .  Impaired glucose uptake and utilization are likely to be common to these diseases. However, the study results so far are not representative because they are either based on studies on animals or with very few study participants.

In any case, all of the diseases mentioned require individual and medically controlled therapy – the additional use of the keto diet should always be discussed with the doctor.

Keto Diet and Cardiovascular Disease

Some studies, such as the 2013 study by Paoli et al., ⁹  have found improvements in body fat, blood pressure, blood sugar and cholesterol levels as part of a ketogenic diet. This could also reduce the risk of cardiovascular disease.

German consumer centers warn, however, that the keto diet could result in cardiovascular diseases. The findings of such studies as those mentioned above should therefore be evaluated with caution as long as there are not enough studies to make reliable statements – especially long-term studies have so far been lacking.

Does a ketogenic diet help with cancer?

There is also scientific debate as to 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 ^14,15,16  indicate effectiveness, other studies ^6,17 have  not been able to confirm this effect and bemoan the lack of high-quality studies.

It must also be considered that cancer cells are very adaptable and therefore probably cannot be eliminated through diet. However, the ketogenic diet may play a role as a supporting element in cancer therapy.

The keto diet in sports

In addition to medical patients, some athletes should also be able to benefit from the ketogenic diet: it is said to improve performance and help to lose weight quickly before a competition, for example. However, this has not been scientifically proven.

Strength athletes  often eat ketogenic food for visual reasons. Because the keto diet dehydrates the body, which makes the muscles more visible.

The ketogenic diet is not suitable for  endurance athletes  such as runners or climbers. Because this group of athletes needs sufficient glucose due to the sustained physical exertion – and for that it needs  carbohydrates .

Who is the keto diet not suitable for?

A ketogenic diet is not for everyone, as some groups of people can be seriously harmed and should steer clear of the low-carb, high-fat diet.

These groups of people include people with

• Elevated blood lipid levels:  If you suffer from hyperlipidemia (elevated cholesterol, triglyceride and lipoprotein levels), the body cannot break down fat properly, which is why a high-fat diet can become a problem.
• Heart diseases 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 with gallstones or a removed gallbladder: Fat digestion is more difficult in people with diseased or absent bile, so that 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 while providing it with a lot of fat to break down.
• Underweight  or an eating disorder:  Those affected are already struggling with a nutrient deficiency and also have to gain weight instead of losing weight.

If you want to try the keto diet despite one of these diseases, you should never do so without consulting a doctor.

Ketogenic diet during pregnancy

So far there are no scientific studies on this topic.

However, in order to be able to guarantee the normal development of the baby, pregnant women are generally recommended  not to go on any diet  and instead  to eat a balanced diet.  This also includes the consumption of carbohydrates.

Conclusion: Is a ketogenic diet healthy?

For people with conditions like epilepsy, a keto diet may have health benefits. Rapid weight loss can also be achieved with this diet.

But consumer advice centers warn of a lack of vitamins, fiber and phytochemicals in the keto diet. 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 Society for Nutrition (DGE) recommends generating only 30 to 35 percent of the energy a day from fats.

The keto diet should, if at all, only be used under medical supervision and, if necessary, with the help of a nutritionist. If you want to lose weight in the long term and without  the yo-yo effect  , you should make your diet more balanced and healthy and exercise regularly.