When nutritional research is dominated by epidemiology, controlled trials are welcome and always worth reviewing. This week’s note is the latest dietary trial involving Professor Christopher Gardner, who has been prolific in this field. Gardner was the senior author for the DIETFITS study, which we reviewed three times previously (Ref 1). Gardner was the lead author of this week’s paper, which was called “Effect of a ketogenic diet versus Mediterranean diet on glycated hemoglobin [HbA1c] in individuals with prediabetes and type 2 diabetes mellitus: The interventional Keto-Med randomized crossover trial” (Ref 2).
As befits a good title, we know from the heading that this study sought to establish whether the keto diet or the Mediterranean diet performed better in people with borderline or diagnosed type 2 diabetes (T2D). The key outcome of interest was HbA1c, which is a measure of the sugar in the blood over the past three months. Finally, we know that it was a crossover trial, which means that all participants tried both diets. As a result, we don’t need to take into account how different people were in each part of the trial; everyone took part in both interventions. We will see that the title didn’t allow for nuance and that the Mediterranean diet was an adapted Mediterranean diet and there was another (medications) twist.