Background
Very low carbohydrate ketogenic type diets (VLCKD) have been shown to be more effective for body weight reduction and fat loss compared to balanced or low-calorie Mediterranean diets, at least in the short-medium term [1, 2], although the underlying mechanisms of its efficacy are still not well understood. Despite being a diet in widespread use there are few data available regarding effects on respiratory ratio (RR) [3, 4] and resting energy expenditure (REE) and, more specifically, there are no reports about the effects on RR following a return to a non ketogenic diet. The aim of this study was to compare the effects of a 20 day ketogenic Mediterranean diet with phytoextracts (KEMEPHY) and a low-calorie Mediterranean diet (MD) on RR and REE during and 20 days after finishing the ketogenic phase.