A ketogenic diet reduced liver fat more effectively than a Mediterranean or a low-fat, plant-forward diet — even when all three led to the same amount of weight loss — according to a tightly controlled clinical trial.
Researchers at Washington University School of Medicine in St. Louis studied 42 participants with obesity, prediabetes and elevated liver fat, randomly assigning them to one of three diets and supplying all their food for four to five months. The diets: ketogenic (4% carbs, 73% fat), Mediterranean (50% carbs), and plant-forward/low-fat (70% carbs). The findings appeared in Cell Metabolism.
What they found
The keto group cut liver fat by 67%, versus about 45% in each of the other groups — despite a similar ~10% body-weight loss across all three. About half of keto participants no longer met prediabetes criteria, versus 29% (Mediterranean) and 7% (low-fat). Notably, the keto group did not show increased blood fats or cholesterol despite the high fat intake — which the researchers called the most surprising result.
Why it matters — and the caveats
“Reducing carbohydrate intake can have important therapeutic effects on metabolism beyond just weight loss alone,” said senior author Samuel Klein. Still, this was a small study (42 people) under controlled feeding — conditions hard to replicate in daily life — and it focused on people with prediabetes and high liver fat. It doesn’t mean keto is right for everyone, and cholesterol responses can vary between individuals. This article summarizes research and is not medical advice.