Keto Diet Trial Links to Higher Prediabetes Remission

What Happened

A clinical trial published Aug. 27, 2026, in Cell Metabolism reported that a ketogenic diet produced larger improvements in several liver and metabolic markers than a Mediterranean diet or a low-fat, plant-forward diet in adults with obesity.

All participants in the trial were assigned a diet for about four to five months and had their calories adjusted so they lost about 10% of their body weight, allowing the researchers to compare metabolic effects beyond weight loss itself.

What The Study Tested

The researchers enrolled 42 participants with obesity, prediabetes, and fatty liver disease and randomly assigned them to a ketogenic diet, a Mediterranean diet, or a low-fat, plant-forward diet.

Participants received all food from the research team and met weekly with a dietitian to support adherence to the assigned diet.

What The Trial Found

All three diets reduced body fat and improved insulin sensitivity, which is linked to better blood-sugar regulation.

The ketogenic diet group showed the largest average decrease in liver fat (67%), compared with 45% in both the Mediterranean and plant-forward groups, and the ketogenic group had the highest reported prediabetes remission rate after the intervention.

• Average liver fat decreased 67% in the ketogenic group vs 45% in both comparison groups.
• About 50% of the ketogenic group no longer met criteria for prediabetes vs 29% (Mediterranean) and 7% (plant-forward).
• The ketogenic diet group had the largest increase in glucagon during 24-hour blood monitoring and the greatest reduction in blood insulin levels compared with the other diets.
• The report notes the ketogenic group did not show an increase in blood fat or cholesterol levels despite consuming the most fat.

Why This Matters for Metabolic Health

For readers managing obesity, prediabetes, or fatty liver disease, the trial’s design suggests that carbohydrate restriction may affect liver fat and glucose-related hormones even when weight loss is held roughly constant across diets.

The study authors highlight a subgroup framing: the corresponding author says the data suggest that, for people with high liver fat content and prediabetes, reducing carbohydrate intake can have therapeutic effects on metabolism beyond weight loss alone.

• The ketogenic diet in this trial was very low in carbohydrates (4% of calories) and high in fat (73%).
• The Mediterranean diet in this trial provided 50% of calories from carbohydrates and 35% from fat.
• The plant-forward diet in this trial provided 70% of calories from carbohydrates and 15% from fat.

Limitations And What the Results Do Not Settle

The findings come from a single clinical trial with 42 participants who all had obesity, prediabetes, and fatty liver disease, and the intervention lasted about four to five months, so the results may not apply to other groups or to longer time frames.

Because participants were provided all their food and had weekly dietitian support, outcomes in typical real-world settings, where adherence varies and food is self-selected, may differ.