2.2.1 The classic ketogenic diet (CKD)

Created by Wilder in the 1920s [1], the CKD is the oldest of all ketogenic diet therapies and in its purest form consists of 80% fat by weight (roughly equivalent to 90% fat by caloric intake), translating to a 4:1 ratio of fat to protein plus carbohydrate, although a 3:1 ratio or lower can often be used [2]. In the CKD, the fat source consists predominantly of long-chain fatty acids, obtained from standard foods.
