Keto Diet May Offer Benefits Beyond Weight Loss

• A recent study has shown that a ketogenic (keto) diet may offer more health benefits for people with obesity than other weight loss diets. 
• The researchers compared a keto diet with the Mediterranean diet and a low fat, plant-forward diet. 
• All three diets led to weight loss and reduced body fat, but the keto diet offered more benefits for liver and metabolic health.

A diet that severely limits carbohydrates, but is high in fat, like the ketogenic (keto) diet, may provide more health benefits for people with obesity than the Mediterranean diet or a low fat, plant-forward diet. 

According to a study that was published in Cell Metabolism on August 27, a keto diet led to about 50% of participants who had prediabetes no longer meeting the criteria for the condition. It also improved liver and metabolic health more than the other two diets. 

The findings suggest that following a keto diet may be an effective option for people who have obesity, prediabetes, and fatty liver disease. 

Keto diet may improve liver and metabolic health

To understand the metabolic effects of the three diets in individuals, the researchers conducted their clinical trial in 42 participants who had obesity, prediabetes, and fatty liver disease. 

The researchers randomly assigned the participants to one of three diet groups: 

• keto diet
• Mediterranean diet
• low fat, plant-forward diet

Each participant received all their food from the research team. They also met with a dietitian weekly to help them adhere to their set diet plan. 

During the study, the keto diet provided 4% of calories from carbohydrates and 73% from fat. The Mediterranean diet provided 50% of calories from carbohydrates and 35% from fat. The plant-forward diet provided 70% of calories from carbohydrates and 15% from fat. 

The research team tailored each individual’s calorie intake so that they lost about 10% of their body weight over four to five months.

By the end of the study, all three diets had led to a significant reduction in body fat. The participants also became more sensitive to insulin, improving their ability to regulate blood sugar. 

However, the keto diet group showed the greatest improvement in various markers of liver and metabolic function. For example, liver fat decreased by an average of 67%, compared with 45% in the other groups. 

“The most surprising finding was that participants in the ketogenic diet group didn’t experience an increase in blood fat or cholesterol levels despite consuming the most fat,” Max Petersen, MD, assistant professor in medicine and the study’s first author at Washington University School of Medicine, said in a press release. 

The research team also monitored each participant’s metabolic activities over the course of 24 hours by testing their blood throughout. They found that the keto diet group had the largest increase in glucagon. Glucagon is a hormone that promotes fat loss in the liver. 

The keto diet group also showed the greatest reduction in blood insulin levels, which can help reduce liver fat.

By the end of the study, around half of the keto diet group no longer met the criteria for prediabetes, compared with 29% in the Mediterranean diet group, and 7% in the plant-forward group. 

“The study was small but well-designed and controlled, delivering a clear message: when weight loss is equal, dietary composition still affects the liver,” Yesika Garcia, MD, board certified endocrinologist with Medical Offices of Manhattan, who wasn’t involved in the study, told Healthline. 

She also noted that there are a few important caveats to the study findings.

“The study was small, containing only 42 participants with characteristics that can’t be easily generalized to the population, and lasted about 5 months. And crucially, the benefit to muscle — which is the body’s biggest sugar-burning engine — was identical across all three diets and resulted from weight loss. This means that the real star in metabolic health continues to be weight loss,” she said.

How keto diet differs from Mediterranean and plant-forward diets

The keto (ketogenic) diet is a high fat, very low-carbohydrate, and moderate-protein eating plan. It is designed to induce nutritional ketosis, in which your body begins to derive more energy from fat. It may be beneficial for weight loss. 

Typical macronutrient distribution for the keto diet involves: 

• 50%–60% fat
• 30%–35% protein
• 5%–10% carbohydrates

While the keto diet has grown in popularity, and this study found it can help reduce metabolic risk, Garcia told Healthline that it may not be for everyone. 

She also noted that the keto diet is difficult to sustain over a long period and that diets only work when you follow them. 

Mediterranean diet

The Mediterranean diet is based on the foods regularly consumed by people in countries bordering the Mediterranean Sea. This includes a focus on fruits and vegetables, whole grains, nuts, and legumes. People following a Mediterranean diet typically eat fewer ultra-processed foods and more minimally processed foods. 

It may be higher in carbohydrates and lower in fat than the keto diet. However, as Garcia pointed out, “[The] Mediterranean diet continues to have the deepest, most battle-tested track record for preventing diabetes and heart disease in the long game.” 

The Mediterranean diet may also be more sustainable, as it is a style of eating rather than a diet plan. 

Plant-forward diet

A plant-forward diet also focuses more on fruits, vegetables, whole grains, and legumes. But, unlike a vegan diet, it doesn’t necessarily eliminate all animal-based foods. 

The main focus of a plant-forward diet is that, while meat may be included, it is not the main feature of a meal. 

However you choose to approach eating, Garcia noted that losing weight remains the foundation for metabolic health.  

“For the right person with their doctor in their corner, keto might add a genuine metabolic boost. But mind the food quality, and above all, pick something you can actually stick with that fits your life,” she advised.