A very low-carbohydrate, high-fat diet may provide stronger metabolic benefits for people with obesity than either a Mediterranean diet or a low-fat diet, according to a clinical trial published August 27 in the Cell Press journal Cell Metabolism. After four to five months on a ketogenic (or "Keto") diet, about half of the participants with obesity and prediabetes no longer met the criteria for prediabetes.
"We know weight loss can improve metabolic health in people who are obese," says Samuel Klein, the study's corresponding author at Washington University School of Medicine in St. Louis, Missouri. "Our data suggest that if you have high liver fat content and prediabetes, reducing carbohydrate intake can have important therapeutic effects on metabolism beyond just weight loss alone."
Comparing Three Popular Weight Loss Diets
An estimated 40% of adults in the United States have obesity. Doctors often recommend low-fat, low-carbohydrate, or Mediterranean diets for weight loss, but researchers have not known whether one approach provides extra metabolic advantages beyond the effects of losing weight.
The three diets differ sharply in how much carbohydrate and fat they provide. A low-carbohydrate diet, also known as the Atkins or ketogenic diet, greatly restricts carbohydrates. A low-fat diet, by contrast, can get as much as 70% of its energy from carbohydrates. A Mediterranean diet emphasizes plant-based foods such as vegetables, olive oil, and nuts, along with moderate amounts of fish and dairy. A ketogenic diet can include foods rich in saturated fat, including animal products.
