From 1921 onwards (Wilder “The Effect of Ketonemia on the Course of Epilepsy”, Mayo Clinic Bull. 2:307, 1921), scientific studies on the use of the ketogenic diet as a therapy for epilepsy multiplied. After this initial enthusiasm, interest in the diet waned rapidly in the 1940s and 1950s; it was only rediscovered from the 1970s onwards and is currently used as a therapy for pharmacoresistant epilepsy in most countries worldwide. In recent years, numerous scientific studies on the use of this diet have been published by researchers from all five continents, and especially in English-speaking countries, support from patient and family associations is very strong and contributes to the dissemination and understanding of the diet.