The ketogenic (keto) diet is widely popular as an effective way to lose weight and control blood sugar, and is sometimes even promoted as a long-term health option. However, a new scientific study casts doubt on this picture, indicating that weight loss may come with a hidden metabolic cost that appears over time.
The study, conducted by researchers from the University of Utah Health and published in the journal Science Advances, followed the long-term effects of following the keto diet, and concluded with disturbing results related to liver health, blood fats, and the ability to control blood sugar.
The keto diet depends on reducing carbohydrates to a minimum in exchange for a significant increase in fat, which prompts the body to enter a state known as “ketosis,” where it begins to burn fat and produce ketone bodies as an alternative source of energy. This regimen was originally developed to treat epilepsy, before it later became popular as a weight loss method.
But most previous studies focused on short-term results, especially weight loss, without delving into the long-term health effects.
To address this research deficiency, experts conducted a long-term experiment on adult male and female mice, which were divided into different diet groups, including a strict ketogenic diet based almost entirely on fat. Follow-up continued for more than nine months, with weight, body composition, blood fat levels, liver function, blood sugar, and insulin measured.
The results showed that mice on the keto diet did not gain significantly more weight compared to a high-fat Western diet. However, any increase that occurred was at the expense of fat, not muscle mass, which indicates an unhealthy change in body composition.
The most notable surprise was the appearance of fatty liver disease in mice that followed keto, despite not gaining weight. The accumulation of fat in the liver is a major indicator of serious metabolic disorders.
According to researchers, large amounts of fat do not disappear, but must be stored somewhere, and often end up in the liver and blood. What is noteworthy is that the effect was more severe in males, who showed clear damage to liver function, while females seemed more resistant to this damage, which the researchers seek to explain in subsequent studies.
Serious blood sugar imbalance
In the early stages, the keto diet seemed to lower blood sugar and insulin, which is usually considered a positive advantage. But when small amounts of carbohydrates were reintroduced, sharp and long-lasting jumps in blood sugar occurred, indicating an imbalance in the body’s response to glucose.
The analysis showed that the pancreatic cells responsible for secreting insulin became less efficient, likely due to stress resulting from chronic exposure to fat. Although these disorders improved after stopping the ketogenic diet, the results raise serious questions about its long-term safety.
The researchers warn against rushing to generalize the results, as the study was conducted on animals. However, it highlights potential risks that have not been adequately studied in humans.
The research team stresses that anyone considering following the keto diet, especially for long periods, should do so under medical supervision, bearing in mind that weight loss does not necessarily mean improved metabolic health.
