The keto or ketogenic diet was developed in the 1920s by Dr Russell Wilder at the Mayo Clinic. He prescribed it to kids with severe epilepsy who weren't replying to drugs, and located the diet reduced the regularity and also severity of their seizures. Although, a current study has shown not all children take advantage of the diet. https://www.nm.org/healthbeat/healthy-tips/nutrition/pros-and-cons-of-ketogenic-diet