Keto diet as good as Mediterranean diet for control of HbA1c in diabetics

USA: HbA1c levels did not differ between the ketogenic diet and Mediterranean diet phases, although both diets improved HbA1c from baseline, most likely due to various nutritional similarities, says an article published in The American Journal of Clinical Nutrition. 

There is little agreement on what constitutes an appropriate diet in people with prediabetes and type 2 diabetes (T2DM), particularly between low-carbohydrate choices. As a result, Christopher D Gardner and colleagues conducted this study to compare the effects of two low-carbohydrate diets with three key similarities (incorporate non-starchy vegetables and avoid added sugars and refined grains) and three key differences (incorporate vs avoid legumes, fruits, and whole intact grains) on glucose control and cardiometabolic risk factors in people with prediabetes and T2DM.

Keto-Med was a randomized, crossover interventional study. For 12 weeks, forty individuals aged 18 years with prediabetes or T2DM followed a Well Formulated Ketogenic Diet (WFKD) and a Mediterranean-Plus diet (Med-Plus) in random sequence. Diets shared the three fundamental commonalities mentioned above. WFKD avoided legumes, fruits, and whole intact grains, whereas Med-Plus did. The primary endpoint was the percentage change in HbA1c after 12 weeks on each diet. Secondary and exploratory outcomes were body weight change, fasting insulin, glucose, blood lipids, glucose (continuous glucose monitor), and nutritional consumption.

The key findings of this study were as follow:

1. The primary analysis included 33 people with full data.

2. At 12 weeks, HbA1c levels did not differ across diets.

3. WFKD patients had lower triglyceride levels and increased LDL-C levels.

4. Weight reduced by 8% (1%) vs. 7% (1%) and HDL-C improved by 11% (2%) vs. 7% (3%) for WFKD vs. Med-Plus, respectively; however, there was a significant interaction of diet by order for both.

5. WFKD participants consumed less fibre and 3 fewer nutrients than Med-Plus participants.

6. Data from a 12-week follow-up revealed that the Med-Plus diet was more maintainable.

In conclusion, WFKD was good for higher triglyceride reduction, but it also had possible hazards from raised LDL-C, reduced nutritional intakes from eliminating fruits, legumes, and whole intact grains, and was less maintainable.

Reference:

Gardner, C. D., Landry, M. J., Perelman, D., Petlura, C., Durand, L. R., Aronica, L., Crimarco, A., Cunanan, K. M., Chang, A., Dant, C. C., Robinson, J. L., & Kim, S. H. (2022). Effect of a Ketogenic Diet versus Mediterranean Diet on HbA1c in Individuals with Prediabetes and Type 2 Diabetes Mellitus: the Interventional Keto-Med Randomized Crossover Trial. In The American Journal of Clinical Nutrition. Oxford University Press (OUP). https://doi.org/10.1093/ajcn/nqac154