“Fat makes you fat”. At least since the hype of the ketogenic diet, we have known that the opposite can be achieved with a high-fat diet. A large number of people have known the state of ketosis since the Atkins diet – which became popular in the 1970s – in which carbohydrates are almost completely avoided and only fat is permitted as an energy source. The ketogenic diet is also used in the treatment of diseases, for example the ketogenic diet has been used as a form of therapy to combat epilepsy for around 100 years. The ketogenic diet also has health-promoting properties for the effects on the brain and inflammatory markers. Nevertheless, the change is a massive intervention in the metabolism, which should ideally be accompanied by experts. In the following I report from specialist articles, non-fiction books and my own experience.

The diet of most people today is rather low in protein and high in carbohydrates. As the body’s “favourite source of energy”, the need for carbohydrates is highly dependent on how much energy is actually consumed. People who work mainly in the office and hardly move beyond that require far less energy than their diet allows for. At the same time, the lipid metabolism atrophies, which leads to lifestyle diseases such as insulin resistance, obesity, and type 2 diabetes. That is why a reduction in carbohydrates in the western diet very often has positive effects. Especially since carbohydrates are not essential for humans. This means that people can also live (survive) without carbohydrates. On the other hand, without fat and protein, we would die in the long run.

Our brain needs fat for various processes and as a building material. Because fat molecules cannot cross the blood-brain barrier, they are converted to ketone bodies in the liver. These can then pass through the barrier unhindered via the bloodstream and be used, among other things, to generate energy. Ketones are primarily produced during fasting and/or during the ketogenic diet. The state of ketosis is therefore a natural process and important for our metabolic flexibility. The more flexible we react to nutrients, the more adaptable our organism behaves.

In principle, the ketogenic diet is the most extreme variant of the low-carb diet. The carbohydrate content may be around 10-50g daily. However, this also depends on the carbohydrate intake at which the body remains in ketosis and can vary from person to person.

The use of ketones has an antioxidant and anti-inflammatory (anti-inflammatory) effect on our central nervous system. This in turn has a positive effect on the health of our brain and our nerve cells, since, for example, neurodegenerative diseases are repeatedly accompanied by inflammatory processes. Ketones generate less oxidative stress in the nervous system than carbohydrates and can also be used to generate energy in strong states of excitement. Overexcitation occurs, for example, in various diseases such as epilepsy, but also in high stress or traumatic brain injuries.

They improve the oxidative metabolism of mitochondria. Also, the more dominant fat metabolism in contrast to the normally very active carbohydrate metabolism caused by the wrong diet usually improves the sugar metabolism. You can tell by the fact that the glucose uptake in the cells improves and you become more glucose tolerant. This results in improved ATP production and protects nerve cells and nerve tissue. The ketogenic diet shows an approximately 50% lower seizure frequency, especially in drug-resistant epilepsy. In addition, this form of nutrition also shows improvements in other neurological diseases such as dementia or Parkinson’s. Ketone bodies have a positive influence on the motor function, which is disturbed in many neurological diseases. By using a ketogenic diet, sudden neuronal discharges, such as those that occur during an epileptic seizure, are significantly reduced.

Almost all organs can absorb ketone bodies from the blood and use them for energy production. After an adaptation phase of several days, the central nervous system is able to cover about a third of its energy needs from ketone bodies. The kidneys and heart muscle even prefer ketone bodies to glucose as a source of energy. The health-promoting effect of the increased ATP production leads to a greater availability of various neurotransmitters, which contributes to the optimal functioning of the nervous system. Insomnia, depression, and anxiety disorders can lead to greater use of serotonin. The neuroprotective function of the ketogenic diet can reduce serotonin consumption and reduce symptoms of inadequate serotonin levels, such as those of depression. Ketosis supports brain health and reduces possible neurodegenerative processes in the future. Functioning neuronal networks are relevant for healthy brain activity and cognitive abilities. Although our brains function on glucose, research shows that glucose destabilizes neuronal networks, while ketones stabilize those networks. The sharp increase in dementia cases in recent years makes the ketogenic diet a realistic strategy for disease prevention.

Reducing oxidative stress from ketones causes greater glutathione production in the brain. The increased glutathione production is mainly found in the hippocampus, which is responsible for the emotional world. In depressed people, the hippocampus is smaller than usual. Chronic emotional stress and trauma lead to a reduction in volume in the hippocampus. This leads to decreased resilience to future stressors and negative emotional events. This makes it harder to process emotional stimuli. There is now ample evidence that the ketogenic diet improves the balance between GABA and glutamate in the nervous system. Glutamate is the main excitatory neurotransmitter while GABA is the main inhibitory neurotransmitter. Neuronal damage caused by e.g. epilepsy, concussion, or by depression and burnout cause an imbalance between GABA and glutamate. This leads to increased neurological stress and chronic over-excitation in the nervous system. The result is rapid fatigue of the nerve cells and chronic hypersensitivity in many areas of the brain, which can lead to light and noise sensitivity, increased sensitivity to crowds, headaches or even migraines and tinnitus. It is not uncommon for those affected to tire quickly and suffer from sleep disorders and concentration problems.

The hypothalamus, which is often enlarged in depressed people and is the seat of our central stress control system, can be negatively influenced by a carbohydrate-rich diet with a high sugar content (compared to a high-fat diet with the same amount of calories) and the resulting inflammatory processes. A high-fat diet with a calorie surplus generally does not have this effect. In order to avoid hypothalamic inflammation, a high intake of high-glycemic carbohydrates should be avoided.

In addition, the reduction in glucose metabolism has an analgesic effect, which reduces the perception of pain. That’s why I recommend my pregnant clients to avoid sugary foods in the last 6 weeks of pregnancy.

Glucose metabolism is also an important mechanism in Alzheimer’s and is often disrupted, which is why Alzheimer’s dementia is often accompanied by insulin resistance in the brain. Because of this metabolic disorder, using ketone bodies as a primary energy source often works better. In Alzheimer’s, the deficits in glucose metabolism become apparent years before the first symptoms of Alzheimer’s dementia. Laboratory values ​​such as fasting blood sugar, insulin and HOMA-IR are therefore very well suited to uncovering possible deficits in the glucose metabolism in good time and thus counteracting the development of Alzheimer’s dementia and other neurodegenerative diseases at an early stage.

In order to also go into the nutrient supply of a ketogenic diet, the usually increased meat consumption should be discussed here in particular. This is particularly beneficial for the brain. The brain is mostly made up of fat, cholesterol, protein, some vitamins and minerals. The vitamins and minerals primarily serve neurochemical processes, e.g. the production of neurotransmitters, which act as biochemical messengers in the body. These are important for mood, behavior, drive, etc. Among other things, we need zinc for the production of the messenger substance serotonin, vitamin B6 and iron for all neurotransmitters, vitamin D3 for calcium regulation, B12 for the formation of the myelin sheath, magnesium for glutamate inhibition and omega 3 as a building block for the brain and neuronal signal transmission not only in the brain, but everywhere in the body where electrical signals are transmitted. Plant-based foods do not always have all the nutrients or make absorption more difficult due to different amounts of anti-nutrients. A carnivorous (meat(e)eater) or ketogenic diet tends to be packed with all the necessary vitamins and minerals, since muscle and organ meat contain all the nutrients needed for the brain.

A vegan diet can also lead to better glycemic control and lower inflammation levels. This also supports a better inflammatory status and has a stabilizing effect on blood sugar levels. A balanced diet with a healthy (normal) lifestyle should be preferred to a purely plant-based diet with regard to the nutrient deficits mentioned above.

The high fat content of the ketogenic diet not only affects the neuronal plasticity described above through the polyunsaturated omega 3 fatty acids; also, saturated and monounsaturated fats – which make up the core structural fats of the body – are not harmful even at high doses. Monounsaturated fats are known for their beneficial effects on risk markers such as cardiovascular disease. It has been shown that you can reduce LDL cholesterol (including oxidized ones) and triglycerides and increase the good HDL cholesterol. They reduce inflammation and lower blood pressure.

The EPA and DHA contained in omega 3 fatty acids are mainly found in high-fat cold-water fish such as salmon, mackerel, herring, anchovies, sea bass, as well as in shellfish such as oysters and mussels, and also in large quantities in grass-fed animals. A lack of these fatty acids can contribute significantly to many physical ailments. DHA is also essential for optimal brain development. It therefore makes sense to ensure a good ratio of omega 3 to other fatty acids and to regularly consume monounsaturated fatty acids (olive oil, avocado).

In practice, it has been shown that a drastic reduction in carbohydrates can be problematic in the case of severe stress. Metabolic disorders can lead to an aggravation of the respective stress symptoms. Ketones have a positive influence on the regulation of neurotransmitters, but can have a negative effect on serotonin levels if they are already reduced, e.g. due to depression or severe stress. For this reason, it should be clarified beforehand to what extent a ketogenic diet makes sense. Since the organism in many people is adjusted to carbohydrates, a change in diet can initially be accompanied by symptoms such as sleep disorders, headaches, lack of energy and fatigue. After the metabolic change, however, many speak of increased alertness. Digestive and bowel problems can also be side effects.

The Cardiology Association of the American College of Cardiology is critical of the ketogenic diet because many studies have shown that it leads to an increase in LDL cholesterol. Conclusive long-term studies on this side effect do not exist. In addition, the ketogenic diet is not implemented with a calorie surplus, so that a disproportionate accumulation of fat is not possible. In addition – as mentioned above – the “good” HDL cholesterol is also increased. This should always be taken into account when assessing the cholesterol value, since the ratio of HDL to LDL is particularly meaningful.

In diabetes mellitus, a severe lack of insulin can lead to acidosis, since the acidic ketone bodies are not metabolized due to the sufficient supply of glucose and accumulate in the body.

It is not insignificant that the sudden switch to the ketogenic diet can lead to considerable water loss in the initial phase. This in turn is accompanied by a significant loss of electrolytes, which can be life-threatening. When changing your diet, you must therefore pay particular attention to an adequate and balanced intake of sodium, potassium and magnesium.

For an exerciser whose body has adapted to phosphate and oxygen-independent carbohydrate metabolism for energy supply, it can take about 6 months for the system to switch to ketone bodies. At times it can make sense to adapt your training to the ketogenic diet.

A keto study of strength athletes found significant benefits of the ketogenic diet compared to a typical western diet [Rauch et al., 2014]:

Fat-free mass at 11 weeks:
➖Keto: 4.3 +/-1.7kg
➖WD: 2.2 +/-1.7kg

Muscle mass (ultrasound measurement) after 11 weeks:
➖Keto: 0.4 +/-0.25cm
➖WD: 0.19 +/-0.26cm

Ultimately, it can be said that a low-carbohydrate diet is healthy for most people, if only because of the increase in fat metabolism. The extreme form of “ketogenic nutrition” definitely increases metabolic flexibility in the short term, which helps many people to have a healthier metabolism. In particular, people with a high fat content benefit from a reduction in carbohydrates and an increase in fat content. Fats ensure the right signals (saturation, reward center, etc.) and the neurotransmitter balance, and the reduction in carbohydrate intake calms the overwhelmed pancreas through insulin resistance and regenerates insulin-sensitive organs. An increase in fat metabolism protects the cells (mitochondria) and reduces inflammatory processes. Research has shown that the ketogenic diet can be used very successfully for diseases such as epilepsy and Alzheimer’s dementia, both as a preventive measure and as a form of therapy. The ketogenic diet can also help with chronic pain and depression and should at least be considered as an alternative or in addition to medication.

However, the change in diet should be accompanied professionally at least in the initial phase. Deficiencies should be clarified by a doctor. It also makes sense to check your blood values ​​monthly at the beginning in order to identify any misconduct in the implementation or individual reactions to the metabolic adaptation at an early stage. Of course, the ketogenic diet should always be understood here in the context of a healthy lifestyle. This includes a balanced diet with little to no processed food. Adequate intake of omega 3 and monounsaturated fatty acids should also be ensured.

In order to primarily reap the benefits of a ketogenic diet, I recommend a cyclic ketogenic diet, which alternates periods of higher carbohydrates with periods of ketosis, for most people. This trains the metabolism and the body can “switch” from burning fat to burning carbohydrates faster and faster.

Here are my practical tips for the ketogenic diet:

• Avoid protein and carbohydrate intake after training: The reason is the increased fat oxidation in the first hours after training. Then the ketone body production is particularly high.
• Adjust protein consumption: Excessive amounts of protein cause insulin to be released and have an anti-ketogenic effect.
• Excessive amounts of protein are used for energy production by gluconeogenesis and prevent ketosis.
• Larger amounts of isolated protein (e.g., post-workout whey) can disrupt ketone body production.
• Moderate amounts of BCAA (branched-chain amino acids) are good (even when fasting), as they act synergistically with the ketogenic diet and increase ketosis.
• A small amount of readily available carbohydrates before training can increase performance during training (e.g. 10g glucose).
• The general rule is: try it out!

I’ll show you exactly how to do this in my Nutrition Guides.