A ketogenic diet reduces liver fat significantly more than a Mediterranean or low-fat diet, despite achieving the exact same amount of weight loss, according to a study published in July 2026 in the journal Cell Metabolism. Researchers led by Samuel Klein at the Washington University School of Medicine in St. Louis found that participants on a very low-carbohydrate, high-fat diet experienced a 67 percent decrease in liver fat.
Liver Fat Reduction Under Ketogenic Diets
According to the findings published by Samuel Klein’s team at the Washington University School of Medicine in St. Louis, the randomized study investigated how distinct nutritional compositions affect liver metabolism in individuals with obesity, prediabetes, and fatty liver disease. Participants achieved comparable overall weight loss across all three dietary regimens, yet the metabolic outcomes differed sharply. Under the tested keturogenic diet—which comprised 4 percent carbohydrates and 73 percent fat—liver fat content dropped by 67 percent. By comparison, participants following a Mediterranean diet or a low-fat, plant-based diet saw a 45 percent decrease in liver fat.
Impact on Prediabetes Remission and Insulin Secretion
The study also tracked the reversal of prediabetes and 24-hour insulin secretion rates among the cohort. Following a 10 percent reduction in body weight, 50 percent of participants in the ketogenic group achieved complete prediabetes remission. In contrast, prediabetes remission occurred in 29 percent of the Mediterranean diet group and just 7 percent of the low-fat diet group. Furthermore, 24-hour insulin secretion dropped by 74 percent in the ketogenic cohort, compared to a 44 percent reduction in the Mediterranean group and a 27 percent decrease in the low-fat group.
Cardiovascular Risk Factors and Saturated Fat
Data from the Cell Metabolism study challenge conventional assumptions regarding dietary fats and cardiovascular health. Even though the ketogenic diet contained a 23 percent saturated fat share, researchers observed no adverse changes in LDL cholesterol levels or blood pressure among participants. This finding indicates that high saturated fat intake within specific caloric and metabolic contexts does not automatically trigger a worsening of cardiovascular risk markers, according to the published data.
Study Design and Limitations
The randomized trial initially enrolled 55 subjects, with 42 individuals completing the entire protocol—averaging 14 participants per dietary group. Participants had an average age of 43 years and a mean body mass index (BMI) of 38.9. Because the final analysis included a relatively small sample size of 14 people per arm, researchers emphasize that caution is warranted when generalizing these findings to broader populations. Future, larger-scale investigations are necessary to confirm whether these metabolic advantages translate to diverse demographic groups and to evaluate the long-term cardiovascular impacts of strict ketogenic protocols.