Scientists fear that the ketogenic diet could lead to the formation of fatty liver disease. Is the keto diet actually harmful to the liver?

Does the ketogenic diet harm the liver?

If you want to lose weight and are looking for a suitable diet, you will quickly come across the ketogenic diet – a particularly low-carbohydrate form of the low-carb diet. Those who follow a ketogenic diet cover their energy needs in particular from fats and proteins. Carbohydrates are reduced to a minimum. Consequently, the ketogenic diet particularly appeals to those people who love fatty foods, such as butter, cheese, and fatty meats.

However, those who want to lose weight are usually overweight – and overweight people often have non-alcoholic fatty liver disease (NAFLD). If these people now switch to a ketogenic diet, it could exacerbate the fatty liver problem even further and lead to serious secondary diseases, fears Hugo Rosen, a liver specialist and dean at the University of California USC School of Medicine ( 1 ).

Can it really be that the ketogenic diet, which – if implemented correctly (!) – is known to cure many diseases, is now suddenly supposed to harm the liver?

What is fatty liver?

In fatty liver, the liver stores more and more fats and eventually becomes fatty. Once the most severe fatty liver stage has been reached, two-thirds of the liver consists of fat-filled cells.

Fatty liver disease generally does not cause any symptoms at first, so it is called a “silent killer” and most sufferers only find out about their fatty liver when it has already developed to a more advanced stage, such as cirrhosis of the liver, non-alcoholic steatohepatitis (NASH, inflammatory liver disease) or even liver cancer.

Fatty liver also makes you susceptible to other forms of cancer and is also considered a risk factor for type 2 diabetes. In the case of fatty liver, the risk of dying from a heart attack or stroke also increases by more than twofold.

More and more people have fatty liver disease

“In the past, most of my patients had hepatitis C, but today the majority have fatty liver,” says Rosen. In the meantime, 25 percent of the world’s population suffers from fatty liver, and in industrialized nations it is even up to 35 percent. In Australia, fatty liver disease is already the most common chronic liver disease. According to Rosen, the main cause is the ever-increasing obesity.

Fatty liver can be diagnosed via blood tests as well as ultrasound or MRI examinations. There are no medications yet, but they want to change that quickly. This is understandable, as the mass of those affected attracts high profits. Basically, however, it is absurd, especially since it is a diet and lifestyle-related condition that could be remedied by weight loss including a change in diet. Then the fat dissolves in the liver and the inflammatory processes that have arisen decrease.

Liver specialist says ketogenic diet can cause fatty liver

A high-fat diet, on the other hand, such as the ketogenic diet, according to Rosen, can cause fatty liver, as studies on mice have shown. In the ketogenic diet, 80 percent of calories are consumed in the form of fat, so the formation of fatty liver in the mice is not surprising, says Dr. Rosen.

Since the University of Southern California does not provide its mouse studies, it is not possible to verify how specifically the mice were fed, what the quality of the diet was, whether they were also given vegetables, whether they were actually in ketosis, and whether only the energy requirement was met or whether it may have been exceeded.

It depends on the quality of the ketogenic diet!

The ketogenic diet can also be designed quite differently. If it is composed of healthy fat and protein sources, the food is natural, if you consume the permitted amounts of carbohydrates in the form of vegetables (especially leafy greens) and if you are careful not to exceed your energy needs, it is hard to imagine that it should harm the liver.

Presumably, Rosen refers to overweight people who are looking for a way to lose weight quickly, who then read on the Internet or other media that you can achieve exactly that with a “flash diet” called a ketogenic diet and now simply eat any fatty foods without any background information, possibly in far too large quantities. In this case, it would not be surprising if fatty liver disease developed or worsened.

Ketogenic diet can even regress fatty liver

However, if the ketogenic diet is implemented correctly, it can contribute to the regression of fatty liver (as several studies on humans (!) show (3 ) ( 4 ) ( 5 ) ( 6 ) – of course always in combination with exercise, optimization of the supply of vital substances, intestinal cleansing and alcohol abstinence. Alcohol in particular rapidly deteriorates liver health, especially if the liver is already ailing, i.e. fatty.

For example, the 2018 review by Gershuni et al. found no connection whatsoever between a properly administered ketogenic diet and fatty liver. Here, the state of ketosis has been found to improve metabolic and inflammatory markers, including lipids, HbA1c and highly sensitive CRP, and to support weight management (7).

Therefore, headlines such as “Ketogenic Diet Contributes to Fatty Liver” (2) do not contribute to a concern as long as they implement this form of diet CORRECTLY.