A recent study compared the effects of a keto diet and a Mediterranean diet on blood sugar control, gut health, and weight loss. In this small study involving individuals with newly diagnosed diabetes, the keto diet showed superior results in improving metabolic health metrics compared to the Mediterranean diet. Notably, the keto diet led to better outcomes in blood sugar levels, gut microbiota composition, BMI, and waist circumference. However, the study also highlighted that the benefits of the keto diet were not sustained over the long term, with advantages diminishing after 6 months.
The keto diet, known for its success in weight loss, involves a drastic reduction in carbohydrates to shift the body’s energy source to burning fat. While it can yield significant weight loss and other benefits, the keto diet has been associated with various adverse effects, particularly with prolonged use, making it challenging to study safely in human subjects.
In contrast, the Mediterranean diet takes a more balanced approach to nutrition and lifestyle without extreme carbohydrate restrictions. The study enrolled participants aged 45 to 65 with obesity and newly diagnosed type 2 diabetes who had not yet started any medication for the condition.
Individuals were randomly assigned to either a low-calorie ketogenic diet or a Mediterranean-type diet. Those in the low-calorie keto group received protein-based meals containing less than 30 grams of carbohydrates per day, with a gradual transition to the Mediterranean diet after 2 months to mitigate safety concerns related to the keto diet. Both groups followed the Mediterranean diet for the remainder of the study from month 4 onwards.
Key findings included the keto diet group exhibiting significant improvements in HbA1c levels, BMI, waist circumference, and beneficial gut bacteria at the 6-month mark compared to the Mediterranean diet group. The study, published in the journal Metabolites, emphasized short-term improvements in gut microbial diversity, anthropometric measures, and metabolic indicators.
In a study focusing on a low-calorie ketogenic diet group, researchers found that there was an increase in beneficial gut bacteria, notably the Akkermansia species, known for its role in metabolic health and gut barrier protection. However, after a six-month period, many of the initial health improvements observed in the participants began to diminish, though they did not regress entirely to pre-study levels. Despite this, the researchers remained optimistic about the potential benefits of the ketogenic diet.
When discussing concerns related to keto diets, Dr. Jason Ng, an expert in endocrinology and metabolism from the University of Pittsburgh, highlighted several risks. These include the possibility of nutrient deficiencies due to a lack of varied vegetable and grain intake, as well as potential liver and kidney issues resulting from the increased demand on these organs to metabolize fats and proteins. Constipation may also arise from a lack of fibrous foods necessary for regular bowel movements. Additionally, Dr. Ng mentioned that mood swings and cognitive difficulties can sometimes occur when the brain is deprived of sugar.
Michelle Routhenstein, a preventive cardiology dietitian, echoed these concerns, noting that some individuals on keto diets may experience elevated blood sugar levels, inflammation, high blood pressure, and adverse changes in lipid profiles. She emphasized the importance of nutrient adequacy, effective meal planning, and a balanced approach to diet rather than following short-term fad diets.
Despite these risks, some experts acknowledge the potential benefits of the ketogenic diet in certain contexts. Dr. Ng suggested that carefully selected, otherwise healthy individuals might experience weight loss and improved gut microbiota with close monitoring to mitigate side effects. He particularly noted the potential value of keto diets in managing obesity and insulin resistance in patients with type 2 diabetes who struggle with weight loss or sugar control.
On the other hand, Routhenstein cautioned against recommending keto diets for individuals with type 2 diabetes due to the heightened risk of heart disease associated with the condition. Instead, she advocated for a Mediterranean diet as a safer and more sustainable dietary approach for managing type 2 diabetes and improving overall health. Dr. Ng supported this view, emphasizing the Mediterranean diet’s effectiveness in controlling blood sugar, facilitating weight loss, and its overall health benefits.
In conclusion, while the ketogenic diet may offer certain advantages in specific scenarios, experts urge caution and emphasize the importance of individualized dietary recommendations based on health conditions and long-term sustainability. Rather than quick-fix diets, a balanced and nutrient-rich approach to eating, such as the Mediterranean diet, is recommended for optimal health outcomes, particularly for individuals with chronic conditions like type 2 diabetes.
