The traditional 4:1 (four parts fat : one part carbohydrate, one part protein) classical ketogenic diet and 41% used the medium chain triglyceride diet (60% MCT fat).

In other words, in the above studies the diet was 66% fat, 17% carbohydrate and 17% protein which is more carbohydrate than Atkin's induction.

A type of fat called medium chain triglycerides appear to stimulate ketosis.