Studies on the Metabolism of Eskimos

It is well known that in most human subjects ketosis appears -when the material metabolized becomes restricted to protein and fat. This condition is observed after several days of fasting, on diets deficient in carbohydrate, and in diabetes in consequence of the loss of ability to metabolize carbohydrate. These facts have led to the view that a certain minimum combustion of carbohy,drate is necessary to avoid ketosis. The diet of the Eskimo has long been recognized as an apparent exception to this view. Being restricted almost wholly to animal tissues and containing therefore ,only a very small proportion of carbohydrate, such a diet might be expected to produce a ketosis. Similar diets fed. to human subjects of temperate zones do so. Although the fact appears not to have been investigated, it has been assumed that Eskimos ,do not exhibit ketosis on their customary diets. To account for this assumed fact it has been suggested that the Eskimos must possess an adaptation to non-carbohydrate diet. In his analysis of the ketogenic and antiketogenic factors, the balance between which seems to determine the appearance or non-appearance of ketosis, Shaffer (1) has considered the Eskimo ,dietary, using the data reported by Krogh (2). According to his .analysis the metabolism of the foodstuffs contained in the Eskimo dietary would not be expected to cause ketosis, because the calculated antiketogenic effect of the large protein ingestion was