Does the keto diet really help

Does the Keto Diet Really Help With Depression?

The keto diet can help with epilepsy and neurodegenerative diseases. But does it also work for depression?


Does the Keto Diet Really Help With Depression? The keto diet is a diet that is essentially based on consuming as much fat as possible and only a minimal amount of carbohydrates. The result is a change in the way the body's cells gain energy, away from carbohydrates and towards fat or the so-called ketone bodies, which are obtained from fat in the liver.

The advantages, it is said, are manifold:

  • Rapid reduction in excess weight
  • Prevention of neurodegenerative diseases such as Alzheimer's and Parkinson's
  • More energy, focus and clarity
  • Higher performance in endurance sports
  • Prevention and alleviation of anxiety disorders and depression
  • Insulin resistance and type 2 diabetes regress
  • Decreased cancer cell growth
  • Reducing the risk of heart disease

This list is not exhaustive, but includes the main reasons why millions of people are now on the keto diet. But as with any diet that makes it to popularity and the health section of breakfast television, the question arises: what is a fact and what is an assertion?

How does the keto diet work?

The basic principle of the keto diet can be outlined in a few sentences. A normal diet, no matter how healthy or unhealthy, has carbohydrates at its center. The human body converts these carbohydrates into a number of simple carbohydrate compounds, mainly glucose, and uses them as a source of energy. Fat is stored for bad days. Likewise, superfluous carbohydrates are partly stored away in the form of glucose and partly after they have been converted into fatty acids.

But the body also has the ability to use fat as a source of energy. But he only does this when he does not have enough carbohydrates available. And that's the whole trick of the keto diet: very little carbohydrates, lots of fat and little to moderate protein.

At the center of the keto diet, and hence the name, are the so-called ketones or ketone bodies. This is a group of chemical compounds made from fat cells in the liver. These can also cross the blood-brain barrier through the blood circulation and be used in the brain in the mitochondria of the brain cells to generate energy. The condition in which more ketones can be found in the blood and the body's energy supply is increasingly based on ketones and thus ultimately fat is called ketosis or ketylose.

Ketosis is not an unnatural condition, but a normal reaction of the body to an insufficient intake of carbohydrates, such as is the case with fasting. After all, there has to be a mechanism that makes all the fat that we store away on the stomach and buttocks for bad days available for the body to use for energy production when the bad days actually occur.

In fact, the observation that fasting can lead to ketosis was the catalyst for the development of the keto diet in the 1920s. Fasting has been used successfully as a treatment for epilepsy since ancient times. Closer studies of the mechanisms of fasting and why fasting can help with epilepsy shed light on the importance of fat metabolism and ketone bodies. The development of more effective drugs in the decades that followed led to a decline in the use of the keto diet, although it is still used today, for example, in children who are unresponsive to these drugs.

Due to the old age of the diet, there are different models of exactly what a ketogenic diet should look like. The classic keto diet, for example, consisted of 90% fat and a maximum of 10 to 15 grams of carbohydrates per day.

The following rule of thumb is currently recommended:

  • 5% to 10% carbohydrates
  • 15% to 20% proteins
  • 70% to 80% fat

The amount of usable carbohydrates, i.e. carbohydrates that the body can actually use for energy, should be less than 50 grams per day, depending on the person even less than 30 grams.

What are the benefits of the keto diet?

With the keto diet, it can sometimes be difficult to distinguish between facts, claims, and wishful thinking. It has been proven that an increased ketone concentration in the blood has a positive effect on the brain metabolism. It has an inhibitory effect on inflammatory processes, has a neuroprotective effect and has a mitigating effect on the balance of neurotransmitters and on the rate at which neurons fire signals.

A positive effect in preventing epileptic seizures has long been proven. Studies also suggest that the keto diet can help with neurodegenerative diseases like Alzheimer's and Parkinson's.

Another area where studies have shown the keto diet to be beneficial is in cancer treatment. Tumors of certain types of cancer such as colon cancer or prostate cancer show less growth and greater sensitivity to chemotherapy under the influence of a ketogenic diet.

See also: Ketogenic Diet as Supportive Cancer Therapy

Despite the nearly one hundred year history of the keto diet and its use to treat neurological disorders, the evidence regarding the treatment of mental disorders such as depression and anxiety disorders is astonishingly manageable. The few studies on the topic are either limited to animal experiments or were carried out with a very small number of study participants. Large-scale, double-blind studies of people specifically targeting the treatment of depression and anxiety disorders are still pending.

Despite the widespread use of a ketogenic diet in the treatment of mental disorders, it must be stated that it is still unclear whether a ketogenic diet will really help with depression in the long term, to what extent it helps, and whether it helps better than other measures.

A study on rats published in 2004 and since then much cited came to the result that rats that were fed a ketogenic diet showed fewer depressive behaviors in a corresponding test compared to a group of rats that was fed normally.

The said test was simply a jar of water that the rats were placed in, and the researchers measured how much time the rats spent moving more than necessary to avoid drowning. The ketogenic rats moved more than the comparison group.

In another animal experiment from 2014, a group of female mice were fed a ketogenic diet for 30 days and then mated. After the boys were born, the babies in the keto group were less susceptible to depressive or anxious behavior than the comparison group, whose mothers were fed normally.

In addition, after killing the mice, there were clear differences in the brain structure, for example the hippocampus involved in learning and spatial orientation, the hypothalamus and the corpus callosum responsible for communication between the two halves of the brain had shrunk, while parts of the cerebellum were enlarged. At the same time, however, a more active neurogenesis in the hippocampus could be determined, i.e. the formation of new nerve cells, which gives rise to speculation, because it is known that this process is weakened in people with unipolar depression. At the same time, however, the hippocampus has also shrunk by an average of 10%, which in turn, with the results of this study, indicates that the volume itself has no meaning, but only the visible effect of other processes.

See also: Study details

Exogenous ketones to achieve ketosis

The body's initial conversion to fat-based energy production is not without problems and poses problems for many people. A completely new menu has to be drawn up, shopping behavior has to be radically changed and anyone who goes to the supermarket with keto glasses quickly finds that the majority of the products on offer are not suitable for keto. Side effects such as dizziness and nausea, hunger, attacks of great craving for sweets and the famous keto flu are not uncommon for the first days and weeks of a keto diet and make some people give up quickly.

One way to speed up the transition process and reduce side effects is to consume so-called exogenous or external ketones. This involves taking in ketones or easily convertible precursors from ketone bodies directly with food, thus increasing the number of ketone bodies in the blood. This also allows you to consume more carbohydrates than you would on a keto-pure diet, making it easier to fill your fridge, plate, and stomach.

Ketone salt and BHB salt

Ketone salt, also called BHB salt, is usually a powder containing the ketone body β-hydroxybutyrate, bound to mineral salts such as sodium, potassium and calcium. Because of their relatively low price, ketone salts are enjoying greater popularity. However, there is evidence that they are not the best way to achieve ketosis. There are two reasons for this:

  • Compared to, for example, MCT oil, the increase in the concentration of ketone bodies when taking ketone salt is relatively small.
  • The high salt content can lead to an unhealthy oversupply of sodium. Some products contain almost 70% of the recommended daily amount of sodium in a serving unit.

Ketone ester

Ketone esters are liquids in which the ketone bodies are not bound to salts, but to alcohol molecules such as glycerine, an ester. They're more expensive than ketone salts, and reports have reported that they taste terrible. On the other hand, they are significantly more efficient at increasing the concentration of ketones in the bloodstream and achieving ketosis without great side effects.

Even if you stick to a normal carbohydrate-based diet, they still work and can put the body in ketosis for a short period of time, up to several hours. Athletes, among others, take advantage of this, as studies have shown that by taking exogenous ketone bodies, an increase in endurance performance and improved regeneration after exercise can be achieved.

MCT oil

MCT oil is made from coconut oil and does not contain any ketone bodies itself. The fats in MCT oil can be converted into ketones very easily by the body, which is why they function more or less like an external source of ketones.

A distinction is made between different types of MCT molecules depending on the molecular structure or the number of carbon atoms in the molecule:

  • C6 (caproic acid): The shortest molecule with six carbon atoms. It converts to ketones quite quickly, but often causes stomach upset.
  • C8 (Caprylic Acid): This form provides the body with the greatest yield of ketone bodies and is the fastest of all MCT forms.
  • C10 (capric acid): Contains 10 carbon atoms and has an anti-inflammatory effect.
  • C12 (lauric acid): With 12 carbon atoms the longest molecule and its properties close to "normal" fatty acids, which is why it does not play a role in the context of the keto diet.

Almost all products on the market are based on caprylic acid (C8) or a mixture of caprylic acid and capric acid (C10).

One of the best-known uses of MCT oil is the so-called bulletproof coffee (literal translation: bulletproof coffee), by which many followers of the keto diet and swear, especially when combining the keto diet with intermittent fasting. Freshly brewed coffee is whisked with butter and MCT oil into a creamy drink and usually drunk as a substitute for breakfast. The drink should have the property of providing the body with sufficient energy for the first few hours of the day without having to consume solid food.

MCT oil is also at the heart of what is known as the MCT diet, which was developed in the 1960s to help people get into ketosis who are struggling to follow the extreme carbohydrate restrictions in their diet. This form of diet takes advantage of the fact that the human body can convert MCT oil to ketones faster and more efficiently than normal fats ingested through the diet. As part of this diet, about 30% to 40% of the energy requirement is covered by MCT oils, 30% by other fats and compared to the classic keto diet, the amount of carbohydrates consumed can be increased up to three times.

Risks and Side Effects of the Keto Diet

The keto diet represents a radical change in diet and it stands to reason that such a step is not without its risks.

Keto flu

A typical phenomenon that affects many people who switch their diet to keto is the so-called keto flu. It occurs in the first days or weeks after the changeover and disappears for the majority of those affected within a week.

The symptoms of the keto flu are different for each person in their occurrence and severity. Symptoms can include:

  • a headache
  • diarrhea
  • Vomit
  • constipation
  • stomach pain
  • dizziness
  • Muscle spasms
  • sleep disorders
  • Difficulty concentrating
  • Increased irritability
  • Fatigue and lack of energy

Not every keto novice is affected by the keto flu. It can be prevented to a certain extent by making sure to drink as much as possible and, despite all restrictions, eat as many vegetables as possible, especially those rich in potassium and magnesium.


Ketosis that is brought about by a change in diet and not by taking external ketone sources, i.e. the classic keto diet, can lead to an excessive level of ketone bodies in the blood and thus potentially to acidosis or ketoacidosis. This is an unhealthy drop in the pH of the blood. The consequences are headache, confusion, tremors, tiredness and dysfunction in the cerebrum, which in severe cases can lead to a coma and even death.

For a healthy person, however, there is little risk of reaching such a dangerous level of ketosis simply by changing their diet. The risk is much higher for people with liver disorders, alcohol problems or a disturbed insulin balance. In particular, type 1 diabetics, who, due to the nature of their illness, are more likely to develop ketoacidosis, should therefore under no circumstances undertake unauthorized experiments. They put their health and life at risk. A detailed discussion with an expert doctor is essential.

Kidney stones

Studies suggest that switching to a ketogenic diet is associated with an increased risk of developing kidney stones. Like type 1 diabetics, people with existing kidney disease should not change their diet or take dietary supplements to induce ketosis without consulting a doctor.


If you take a look around the keto scene, read blogs and discussion groups, then there is often a worrying narrowing of the discussion solely on the question of how much fat you should consume in relation to proteins and carbohydrates. There are recommendations for keto-compliant McDonalds burgers (just leave out ketchup and rolls), recipes for dishes that are half made of bacon, and a general mentality that keto means replacing carbohydrates with butter, eggs and bacon and in the morning sipping bulletproof coffee instead of breakfast.

It is obvious that this cannot be healthy. Switching to a ketone-based energy supply for the body does not mean that the body is no longer dependent on obtaining a multitude of other nutrients, vitamins and minerals from food. It is very easy to go wrong on the keto diet and put yourself in a situation where important nutrients are withheld from the body.


There is much to suggest that the keto diet has a positive effect on the well-being and quality of life of people with depression and anxiety disorders. However, it must also be said that the study situation in this context is still unsatisfactory and is often limited to animal experiments.

The keto diet is not a simple change in diet, but presents you with many problems that can only be mastered by intensely studying the subject matter and planning your daily menu. Side effects of switching are common.

Possible alternatives exist in the form of exogenous sources of ketones such as MCT oils. It is also not clearly known to what extent the exertion of a keto diet pays off in depression and anxiety disorders compared to other forms of nutrition such as the Mediterranean diet or intermittent fasting.

A final judgment is not possible at this point in time.

See also