Study Indicates Keto Diet May Offer Enhanced Metabolic Benefits Compared to Other Diets

Conducted by researchers at Washington University School of Medicine, the study involved 42 participants with obesity, prediabetes, and fatty liver disease. Participants were assigned to one of three dietary plans: a ketogenic diet with 4% of calories from carbohydrates and 73% from fat; a Mediterranean diet comprising 50% carbohydrates and 35% fat; and a low-fat, plant-forward diet containing 70% carbohydrates and 15% fat. All participants underwent a weekly support program with dietitians to ensure adherence.

Over approximately four to five months, the calorie intake for all groups was adjusted so that participants lost about 10% of their body weight, which averaged around 25 pounds. Lead author Dr. Max Petersen stated that while moderate weight loss improved metabolic function similarly across the diets, the ketogenic diet provided additional benefits, including a more significant reduction in liver fat and enhanced insulin sensitivity.

Specifically, participants on the ketogenic diet experienced a 67% reduction in liver fat, compared to a 45% reduction in both the Mediterranean and low-fat groups. They also exhibited the largest increases in glucagon, a hormone involved in blood sugar regulation, and decreases in circulating insulin levels.

Dr. Petersen noted that the lower carbohydrate content of the ketogenic diet likely contributed to reduced insulin levels throughout the day. The results suggest that the changes observed in glucagon levels from dietary protein intake and lower insulin levels could explain the enhanced metabolic benefits of the ketogenic diet.

The implications of these findings became more pronounced when examining prediabetes status after weight loss; about half of those in the ketogenic group no longer met the criteria for prediabetes, versus 29% in the Mediterranean group and 7% in the low-fat group.

Moreover, participants on the ketogenic diet did not experience increased blood fat or cholesterol levels despite the higher dietary fat intake. Dr. Petersen highlighted that the limited carbohydrate intake in the ketogenic diet led to smaller post-meal increases in blood glucose compared to the other diets, resulting in the most significant improvements in hemoglobin A1c and fasting blood glucose levels.

While the study points to the ketogenic diet having pronounced metabolic benefits, it should be noted that the trial was small and lasted only a few months, making it difficult to draw long-term conclusions. The results indicate that dietary composition can influence metabolic health beyond weight loss, particularly for individuals with high liver fat and prediabetes. Larger, long-term studies are necessary to ascertain the durability of these benefits and their effects on conditions like type 2 diabetes. Dr. Petersen concluded by emphasizing that achieving compliance with dietary guidelines is a challenge in real-world settings.