A series of pie charts depicting the calorific contributions from carbohydrate, protein and fat in four diets: the typical American diet; the Atkins diet during the induction phase; the classic ketogenic diet in a 4:1 ratio of fat to combined protein and carbohydrate (by weight); and the MCT oil ketogenic diet.
Sources: 

Last AR, Wilson SA. Low-carbohydrate diets. Am Fam Physician. 2006 Jun 1;73(11):1942-8. PMID 16770923.
Huttenlocher PR, Wilbourn AJ, Signore JM. Medium-chain triglycerides as a therapy for intractable childhood epilepsy. Neurology. 1971 Nov;21(11):1097-103. PMID 5166216.
SHS KetoCal. Cited 18 March 2008.Data values (carbohydrate, protein, fat (LCT) and fat (MCT). Percentage of calories:

Typical American: 50, 15, 35, 0
Atkins (induction phase): 5, 35, 59, 0
Classic ketogenic: 1.6, 8.4, 90, 0
MCT ketogenic: 19, 10, 11, 60.
Vector version of Image:Ketogenic diets pie.png by Colin (talk · contribs)
Colin, vectorized by Fvasconcellos (talk · contribs)