Keto Diet Cuts Liver Fat by 67% in Clinical Trial

A rigorous clinical trial published in the Cell Press journal Cell Metabolism reveals that a very low-carbohydrate ketogenic diet reduces liver fat by an average of 67% in adults with obesity and prediabetes, outperforming both Mediterranean and low-fat plant-forward diets despite matched weight loss targets across all study groups.

Conducted by researchers at the Washington University School of Medicine in St. Louis, Missouri, the trial tackled a clinical debate: whether specific macronutrient distributions offer therapeutic advantages for metabolic health independent of overall weight loss. By strictly controlling caloric intake so that 42 participating adults each lost approximately 10% of their body weight over a four-to-five-month period, investigators were able to isolate the biological impact of carbohydrate restriction from the benefits of shedding pounds.

Metabolic Mechanisms and Clinical Trial Findings

The randomized trial evaluated three distinct nutritional frameworks: a ketogenic diet providing 4% of calories from carbohydrates and 73% from fat; a Mediterranean diet sourcing 50% of calories from carbohydrates and 35% from fat; and a low-fat, plant-forward diet deriving 70% of calories from carbohydrates and 15% from fat. Clinical teams supplied all food directly to participants and mandated weekly consultations with dietitians to ensure strict dietary adherence.

While all three cohorts successfully achieved the targeted 10% weight loss and demonstrated overall improvements in insulin sensitivity, the ketogenic group experienced markedly superior reductions in liver fat. Specifically, liver fat plummeted by an average of 67% among participants following the keto regimen, compared to an average reduction of 45% in both the Mediterranean and plant-forward cohorts.

Furthermore, glycemic control showed improvements. Approximately 50% of participants adhering to the ketogenic diet no longer met the criteria for prediabetes by the conclusion of the trial. In comparison, remission rates were 29% in the Mediterranean group and just 7% in the plant-forward cohort.

In Plain English: The Clinical Takeaway

• Beyond Weight Loss: Cutting carbohydrates drastically provides direct therapeutic benefits for liver fat and blood sugar control that go beyond the advantages of losing weight alone.
• Hormonal Shifts: The keto diet triggers a spike in glucagon and a drop in insulin, helping the body burn fat stored inside the liver more efficiently.
• Cholesterol Stability: Despite consuming a high-fat regimen, trial participants did not see spikes in blood lipids or cholesterol.

Comparative Dietary Efficacy in Recent Research

The findings offer context for healthcare providers managing obesity, prediabetes, and fatty liver disease. With an estimated 40% of adults in the United States currently living with obesity, establishing evidence-based nutritional hierarchies remains a priority.

Photo: diningandcooking.com

This trial demonstrates that severe carbohydrate restriction engages distinct endocrine pathways.

To contextualize these outcomes, the structural components and clinical results of the three trial arms are summarized below:

Dietary Approach	Carbohydrate (% Calories)	Dietary Fat (% Calories)	Average Liver Fat Reduction	Prediabetes Remission Rate
Ketogenic (Keto)	4%	73%	67%	50%
Mediterranean	50%	35%	45%	29%
Plant-Forward Low-Fat	70%	15%	45%	7%

Contraindications & When to Consult a Doctor

References

• Petersen, M., et al. Cell Metabolism.