A clinical trial has found that a ketogenic (or “Keto”) diet reduced liver fat by an average of 67% in people with obesity and prediabetes. This was significantly more than either a Mediterranean diet or a low-fat eating plan, despite all three groups losing the same amount of weight.
Study Design and Participants
Researchers at Washington University School of Medicine in St. Louis enrolled 42 adults with obesity, prediabetes, and fatty liver disease. They were randomly assigned to follow one of three diets: a ketogenic diet, a Mediterranean diet, or a plant-forward low-fat diet. The research team provided all food, and participants met with a dietitian weekly to help them stay on track.
The three eating plans differed in their macronutrient composition. The ketogenic diet supplied just 4% of calories from carbohydrates and 73% from fat. The Mediterranean group got 50% of calories from carbohydrates and 35% from fat. The plant-forward diet derived 70% of calories from carbohydrates and only 15% from fat.
Researchers adjusted calorie intake so that everyone in the study would lose approximately 10% of their body weight. This took roughly four to five months.
Results Across All Three Groups
By the end of the study, participants in every diet group had significantly reduced their body fat and showed improved insulin sensitivity, helping the body control blood sugar more effectively. However, the ketogenic diet produced the strongest changes in several measures of liver and metabolic health.
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Liver fat fell by an average of 67% among people following the keto plan. That compared with an average reduction of 45% in both the Mediterranean and plant-forward groups.
The researchers also tracked participants’ metabolism over a 24-hour period by repeatedly analyzing their blood. People in the ketogenic group showed the largest rise in glucagon, a hormone that helps reduce fat stored in the liver. They also had the greatest decline in blood insulin levels, another change that can help lower liver fat.
Impact on Prediabetes
The ketogenic diet also had the most significant impact on prediabetes. After the weight loss intervention, about 50% of participants following the ketogenic diet no longer met the criteria for prediabetes. However, the source does not provide specific percentages for the other two diets.
The findings were published August 27 in the journal Cell Metabolism.
