Keto Diet Cut Liver Fat by 67% in Obesity Clinical Trial

Keto Diet Led to Largest Liver Fat Reduction

A clinical trial published in Cell Metabolism found that a ketogenic diet reduced liver fat by an average of 67% in adults with obesity, prediabetes, and fatty liver disease. This reduction was greater than the 45% average decrease seen with Mediterranean and plant-forward low-fat diets.

The study involved 42 participants who were randomly assigned to one of three diets: ketogenic, Mediterranean, or low-fat plant-forward. All participants lost about 10% of their body weight over four to five months, but the keto group saw the most improvement in liver fat levels.

Study Design and Who It Applies To

The trial was a randomized, controlled study in which all food was provided to participants, who met weekly with a dietitian to maintain adherence. The participants were adults with obesity, prediabetes, and fatty liver disease.

The ketogenic diet supplied 4% of calories from carbohydrates and 73% from fat. The Mediterranean diet had 50% of calories from carbohydrates and 35% from fat, while the plant-forward diet provided 70% carbohydrates and 15% fat.

Metabolic Health Benefits Beyond Weight Loss

Despite similar weight loss across all groups, the ketogenic diet produced the strongest improvements in several metabolic markers. About half of the keto group no longer met the criteria for prediabetes after the intervention, compared to 29% in the Mediterranean group and 7% in the plant-forward group.

The keto group also showed the largest increase in glucagon and the greatest decline in blood insulin levels, both of which are linked to lower liver fat.

Practical Considerations for Metabolic Health

For people with obesity, prediabetes, and fatty liver disease, reducing carbohydrate intake through a ketogenic diet may provide additional metabolic benefits beyond weight loss alone. The study suggests that diet composition, not just calorie reduction, can affect liver fat and blood sugar control.

All participants in the study received close dietary supervision and regular support from dietitians, which may not reflect typical real-world conditions.

Limitations and Caveats

The study was limited to 42 adults with obesity, prediabetes, and fatty liver disease, so results may not apply to other populations. The intervention lasted four to five months, and long-term effects were not assessed.

Although the ketogenic diet was high in fat, participants did not experience an increase in blood fat or cholesterol levels during the study. However, the findings do not address long-term cardiovascular outcomes.