Confusion in the nomenclature of ketogenic diets blurs evidence

Ketogenic diets have been proposed as a non-pharmacological strategy for the management of several chronic conditions. Their efficacy and safety have been evaluated in the field of neurology, oncology and endocrinology for disorders including cancer, dementia, drug-resistant epilepsy, migraines, obesity, polycystic ovary syndrome and type 2 diabetes mellitus. The nutritional requirements of these subjects are expected to differ significantly. Indeed, although all ketogenic diets restrict carbohydrates, each intervention is characterized by a specific daily calorie intake, macronutrient composition and duration. However, the adopted nomenclature was often unclear to the general reader; also, the same abbreviations for different protocols were used. This possibly resulted in mistakes in the interpretation of the available evidence and limited the impact of studies on the topic in the clinical practice. Adopting a clear and consistent vocabulary is key in any context. Here, we present a practical and clinically-based proposal for the classification and abbreviation of ketogenic diets.