The basics of ketogenic diet: works of Shaffer and Wilder & Winter
It is interesting that while the ketogenic diet becomes well researched as a method for improving energy metabolism during quite a few medical conditions and the number of original research articles as well as reviews grow currently approaching 15,000, only 19 out of all of them cite the original work, which in fact is the basis of the diet. >>> Read more
The ketogenic diet is no longer considered a strictly anti-epileptic diet: its suggested and tested applications includes a broad spectrum of disorders of energy metabolism. The ketogenic ratio formula used in clinics for calculating the ketogenic diet composition was offered by Wilder and Winter in 1922 (1). They argued that the levels of ketogenic substances depend on the ratio between fatty acids and glucose of the metabolizing foods. The ratio when ketogenesis is initiated they called the threshold of ketogenesis: “When the proportion of acetoacetic acid to glucose in such mixtures was that of 1 (or possibly 2) molecules of acetoacetic acid to 1 of glucose, the former substance was completely oxidized. When the proportion of glucose was less, a considerable fraction of acetoacetic acid escaped oxidation.”
Shaffer (2, 3) calculated the number of molecules of ketogenic substrates corresponding to the number of molecules of glucose and concluded that the maximal ratio compatible with the oxidation of the ketogeniec compounds was reached when a ratio of of ketogenic molecules to the number of glucose molecules was 1: 1. He subsequently considered that each glucose molecule is ketolytic for 2 molecules of acetoacetic acid, a 2:l ratio.
Wilder and Winter, 1922 included in their formula the following measurements obtained in clinical settings:
1) basal metabolism for 24 hour periods plus 10 per cent for the specific dynamic action of food and 10 per cent for movements;
2) the calories from the protein metabolism assessed by nitrogen excretion;
3) the calories from fat metabolism taken as the sum of the calories of protein and carbohydrate combined subtracted from the total calories of the day.
The values for carbohydrate and fat are used in the calculation of the ratio between the ketogenic molecules and the glucose molecules (2, 3).
“Under the conditions of these experiments, provided these assumptions are tenable, the ratio between the ketogenic and the glucose molecules at which a clinically significant ketosis appears has a value of at least 2: 1. A ratio of this value implies that every molecule of glucose is ketolytic for 2 molecules of acetoacetic acid.”
- Wilder R., Winter M. Thew threshold of ketogenesis. J. Biol. Chem. 1922 52: 393-401.
- Shaffer, P. A., Antiketogenesis. I. An in vitro analogy, J. Biol.Chem., 1921, xlvii, 433.
- Shaffer, P. A., Antiketogenesis. II. The ketogenic antiketogenic balance in man, J. Biol. Chem., 1921, xlvii, 449.