A recent study finds that while ketogenic, Mediterranean and low-fat plant-based diets all promote weight loss, the keto approach yields the most significant improvements in liver fat and prediabetes markers among adults with obesity.
A new comparison of three widely used diets suggests that, when it comes to shedding weight, the ketogenic, Mediterranean and very low-fat plant-based approaches can all work. But the study, published in Cell Metabolism and reported by ScienceAlert, found that the keto plan delivered the strongest gains in some markers linked to metabolic health, especially liver fat and prediabetes.
The trial involved 42 adults with obesity, prediabetes and excess fat in the liver. Participants were split at random into three groups and followed either a ketogenic diet, a Mediterranean-style diet or a very low-fat plant-based plan for about five months. All three groups lost roughly 10% of their starting weight, suggesting that the biggest difference was not in weight loss itself, but in how each diet affected the body beyond the scales.
According to the study, the ketogenic group showed the largest improvement in liver insulin sensitivity. That matters because poor insulin response in the liver is closely tied to metabolic disease. The amount of liver fat fell by about 67% in the keto group, compared with roughly 45% in the other two groups. Remission of prediabetes was also more common in the keto group than among those eating Mediterranean or low-fat plant-based diets.
Researchers said the likely reason is the diet’s very low carbohydrate content, which in this trial made up only about 4% of total calories. That level of restriction can lower blood glucose and insulin, reducing the liver’s drive to produce new fat while encouraging the body to use stored fat instead. The authors did not find a harmful effect on cholesterol in this study, and some cardiovascular risk markers improved as well.
Still, the findings come with clear limits. The sample was small, and the researchers cautioned that larger studies are needed before drawing firm conclusions about long-term benefits and safety. Medical News Today noted that keto’s strict carbohydrate limits can make it hard to follow over time, with possible drawbacks including fatigue and regained weight. Other research also suggests the Mediterranean diet can improve insulin resistance and liver-related measures in people with fatty liver disease, while broader reviews have linked it with lower cardiovascular and all-cause mortality in people with metabolic risk factors.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
