A popular weight-loss trend is facing fresh scrutiny. A new scientific study has warned that following a keto diet for long periods may significantly increase the risk of liver cancer, raising concerns for millions worldwide.

A new study by American scientists has raised serious concerns about the long-term safety of the keto diet, which is high in fat and extremely low in carbohydrates. While the diet is widely promoted for rapid weight loss, researchers say it may come at a heavy cost to liver health.

Experts note that although keto supporters claim the diet helps people lose weight without hunger, recent evidence points to deeper biological risks.

According to the study, repeated exposure to high levels of fat puts liver cells under constant stress. This stress forces the cells into a more immature state, helping them survive in the short term.

However, researchers warn that these immature cells are more vulnerable to disease and significantly increase the risk of cancer over time.

The study found that long-term high-fat intake causes fundamental changes in the structure and behavior of liver cells. Genes linked to normal liver function weakened, while genes that support cell survival became stronger.

This imbalance, scientists say, creates conditions where cancer can develop more easily.

Findings from animal and human data

The research, published in the scientific journal Cell, involved mice fed a high-fat diet over an extended period. By the end of the experiment, almost all the mice had developed liver cancer.

Scientists warned that once these altered cells acquire harmful genetic mutations, the chances of cancer rise sharply.

Researchers also examined data from human patients suffering from various liver diseases. Similar trends were observed, including weakened liver-function genes and strengthened survival-related genes.

Patients showing these changes were found to have a shorter life expectancy after developing liver cancer.

Timeline and risk factors in humans

Experts explained that changes seen within a year in mice typically take around 20 years to appear in humans. Factors such as alcohol consumption, viral infections, and overall health can accelerate or slow down this process.

These lifestyle factors further push liver cells toward an immature and more dangerous state.

The research team is now exploring whether a balanced and healthy diet can reverse these harmful changes. They are also examining whether modern weight-loss methods, including GLP-1 injections, may help reduce the risk.

Health experts warned that liver disease is no longer confined to older adults or heavy drinkers. Increasingly, younger people are being affected, often without noticeable symptoms until serious damage has occurred.