Butter in your coffee, avocados for breakfast, lunch without potatoes – welcome to the world of the ketogenic diet. While millions of Germans are drastically reducing their carbohydrates and declaring fat the new superstar on the plate, the question arises: are we dealing with a revolutionary form of nutrition or just the next over-hyped diet trend that will soon disappear into oblivion? As is so often the case, the truth lies somewhere in between – and is more complicated than most keto influencers would have us believe.
The promise of fat burning
The basic idea sounds seductively simple: reduce carbohydrates to a minimum, drastically increase the proportion of fat and force your body into ketosis. This is the metabolic state in which the body begins to convert fat into ketone bodies and use them as an energy source due to a lack of glucose. The result? For many, rapid weight loss, which can be particularly impressive in the first few weeks.
Weight loss is just the beginning
Numerous followers report clearer thinking, increased concentration and an end to the afternoon slump. “It’s as if someone has cleared the fog in my head,” is how many keto followers describe their experiences. These subjective reports are supported by initial studies that indicate positive effects on cognitive performance.
Potential for epilepsy
The therapeutic potential of the ketogenic diet is particularly remarkable. It has been used successfully for epilepsy for almost 100 years – long before it became a lifestyle trend. For treatment-resistant seizures, it can reduce the frequency of seizures by up to 50 percent. The first promising results are also being seen in neurodegenerative diseases such as Alzheimer’s.
Cancer cells do not like a ketogenic diet
Even in cancer therapy, the ketogenic diet is moving into the focus of research. The theory: as many cancer cells are primarily dependent on glucose as an energy source, depriving them of carbohydrates could deprive them of a breeding ground. Initial studies suggest that a ketogenic diet could increase the effectiveness of chemotherapy and radiotherapy – a field of research that is still in its infancy, but which gives rise to hope.
Ketogenic diet – the downsides of fat fever
But where there is light, there is also shadow. The ketogenic diet is no walk in the park. The transition to ketosis can be accompanied by the dreaded “keto flu”: Headaches, tiredness, difficulty concentrating and irritability are typical symptoms of this transition phase. For many, this is too high a price to pay for the promise of rapid weight loss.
Long-term threat of nutrient deficiencies
If you ban fruit, pulses and wholegrain products from your diet, you are missing out on important vitamins, minerals and fiber. Particularly critical: the chronic lack of fiber can permanently damage the intestinal flora and increase the risk of intestinal diseases.
Cholesterol risk | LDL
The effects on cholesterol levels are also a cause for concern. The American College of Cardiology warns of an increase in LDL cholesterol – the fraction associated with an increased risk of cardiovascular disease. The often propagated idea that cholesterol levels no longer play a role in a ketogenic diet is scientifically untenable.
Risk of fatty liver
Doctors are increasingly warning of non-alcoholic fatty liver disease (NAFLD) – a silent epidemic in which fat accumulates in the liver without any alcohol consumption. The consequences can be dramatic: Cirrhosis, liver failure or even cancer. Particularly worrying: according to current estimates, around 25% of people worldwide suffer from NAFLD, in the USA even over a third of the population.
Liver expert Dr. Hugo Rosen from the Keck School of Medicine in California puts it in a nutshell: “I used to see mainly patients with hepatitis C – now I almost only see fatty liver.” The reason? High-fat dietary trends such as keto coupled with the global increase in obesity and type 2 diabetes.
Particularly problematic: if you already have a damaged liver, a high-fat diet such as keto risks further worsening the condition. Even if the keto diet works for some people in the short term, it can be dangerous for the liver in the long term, especially if there is no medical supervision.
What science says
A sober look at the current study situation reveals a differentiated picture. Yes, the ketogenic diet can lead to effective weight loss in the short term. However, long-term studies over several years are largely lacking. The few available long-term studies indicate that weight loss after around one year is no greater than with other forms of diet – with significantly greater effort and greater restrictions.
A common fallacy
The positive effects of the ketogenic diet are often attributed to ketosis alone. However, a large part of the benefits could simply be due to the reduction of highly processed foods and sugar – effects that could also be achieved with less extreme diets.
The frequently cited “superiority” of the ketogenic diet over other diets is often based on short-term studies with small numbers of participants. Randomized controlled trials with large cohorts over longer periods of time – the gold standard of nutrition research – are rare and usually do not show any clear superiority.
Particularly questionable
The myth of “burning fat in your sleep”. Ketosis does not significantly increase the basal metabolic rate. The initial rapid weight loss is primarily due to water loss and lower calorie intake – not a magical metabolic change.
Who can benefit from a ketogenic diet?
Despite all the criticism, there are groups of people for whom a ketogenic diet can make perfect sense. People with epilepsy have been shown to benefit, as have patients with certain metabolic diseases. A low-carbohydrate diet – under medical supervision – can also lead to improved blood sugar control in people with type 2 diabetes.
For competitive endurance athletes, the metabolic flexibility promoted by an intermittent ketogenic diet could bring benefits. Some studies suggest that fat burning can be improved during prolonged exercise – a potential advantage in ultra-distance events.
However, the ketogenic diet is not a panacea for the general population. The extreme restrictions make it impractical for most people in the long term. The social isolation caused by the inability to take part in communal meals, the high planning effort and the potential health risks are out of all proportion to the possible benefits.
The keto-industrial complex
What began as a form of medical therapy has long since become a billion-dollar business. Keto bars, MCT oil, exogenous ketones, blood ketone test strips – the market for keto products is exploding. Influencers praise the ketogenic diet as a miracle cure, while at the same time promoting their own product lines.
The irony is obvious: a diet that originally relied on natural, unprocessed foods is increasingly being replaced by highly processed “keto-friendly” products. Keto bread, keto chocolate, keto pasta – the food industry has long since discovered the trend for itself and is now marketing products that contradict the actual idea of the ketogenic diet.
The simplified presentation in social media is particularly problematic. Complex biochemical processes are reduced to simple formulas and potential risks are ignored. The differentiated scientific discourse gives way to simple black-and-white depictions that do not do justice to reality.
Beyond black and white thinking
The ketogenic diet is neither a miracle cure nor the devil’s plaything. It is a tool that can be helpful for certain people in certain life situations. As with any tool, it depends on what you use it for and how you use it.
Instead of a dogmatic either-or approach, a more flexible approach would make more sense. Periodic ketogenic phases could bring benefits for some people without the risks of permanent extreme carbohydrate restriction. The metabolic switch between glucose and fat metabolism could have health benefits that we are only beginning to understand.
Ultimately, the realization remains that there is no one-size-fits-all diet that is optimal for everyone. Genetic factors, lifestyle, state of health and personal preferences play a decisive role. The best diet is the one that is individually adapted, sustainable in the long term and beneficial to health – with or without ketosis.
CONCLUSION
The ketogenic diet has its place in the nutritional landscape, but it is not a holy grail. It is one approach among many, with specific advantages and disadvantages. If you want to try it out, you should do so in an informed, reflective manner and ideally with expert guidance. Because in the end, it’s not about dogmas or trends, but about a diet that suits your own life and your own health goals.
Sources:
- Pathak SJ, Baar K. Ketogenic Diets and Mitochondrial Function: Benefits for Aging But Not for Athletes. Exerc Sport Sci Rev. 2023 Jan 1;51(1):27-33. doi: 10.1249/JES.0000000000000307. Epub 2022 Sep 16. PMID: 36123723; PMCID: PMC9762714.
- D’Andrea Meira I, Romão TT, Pires do Prado HJ, Krüger LT, Pires MEP, da Conceição PO. Ketogenic Diet and Epilepsy: What We Know So Far. Front Neurosci. 2019 Jan 29;13:5. doi: 10.3389/fnins.2019.00005. PMID: 30760973; PMCID: PMC6361831.
- “Keto diet enhances experimental cancer therapy in mice”, by Vicki Conti, NIH, 2024
- ‘Keto-Like’ Diet May Be Linked to Higher Risk of Heart Disease, Cardiac Events, The American College of Cardiology (ACC)
- Fad diets could contribute to liver disease known as a ‘silent killer’, Keck School of Medicine USC
🩺 Medically tested
This article has been professionally reviewed by Dr. Verena Immer. She is a doctor of integrative and anti-ageing medicine with a holistic approach that combines conventional medical knowledge with complementary methods. She has successfully applied the concept of individualized medicine in her own practice near Munich and currently offers personalized medicine – with a focus on longevity – in Switzerland.
Image source: istockphoto.com |
- Balanced food background: credits @ AlexRaths
- Keto word that comes from ketogenic diet | Credits @ SewcreamStudio
- Ketogenic diet food pyramid | Credits @ dimonspace
- Choosing healthy sources of fat. | Credits @ ulijaDmitrijeva
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