Study Finds Long-Term Keto Diet May Cause Metabolic Issues in Mice

The popular ketogenic diet, often admired for its ability to promote weight loss and support low-carbohydrate lifestyles, has been linked to adverse metabolic effects in mice, according to recent research. The diet, characterized by high fat and very low carbohydrate intake, induces a state called ketosis—where the body burns fat for fuel and produces ketone bodies. While this approach has been traditionally used to treat drug-resistant epilepsy in children, its long-term impacts on metabolism have raised concerns.

In a comprehensive study conducted by scientists at the University of Utah and the Utah Diabetes and Metabolism Research Center, mice were divided into four dietary groups, including a ketogenic diet with 90% fat content, a high-fat diet with 60% fat, and lower-fat diets. The mice had free access to their respective diets for up to 36 weeks for males and 44 weeks for females. The findings revealed that although the ketogenic diet helped control weight and supported weight loss, it also led to significant negative effects.

Mice on the ketogenic diet experienced severe hyperlipidemia, indicating high levels of fats in their bloodstream. More alarmingly, male mice developed fatty liver disease and had impaired insulin secretion, leading to glucose intolerance—a precursor for diabetes. Interestingly, female mice appeared less affected, with fewer signs of liver issues. Overall, the study demonstrated that long-term adherence to a ketogenic diet could cause major metabolic disturbances, including liver dysfunction and elevated blood fats.

The research highlights the importance of caution when considering the ketogenic diet beyond its typical short-term use, especially for long-term health benefits. The study's results suggest a need for further investigations into how variations in diet composition affect different sexes and how to mitigate these risks, particularly for those using ketosis for medical reasons such as epilepsy. These findings underscore that while keto diets can support weight management, they may carry substantial long-term metabolic risks that require careful consideration.

For more details, see the full study: Molly R. Gallop et al, "A long-term ketogenic diet causes hyperlipidemia, liver dysfunction, and glucose intolerance from impaired insulin secretion in mice," published in Science Advances (2025).