"Ketosis has had a negative connotation because it was initially discovered in the urine of untreated diabetics, especially those experiencing acidosis. In recent years however, scientists have come to realize that ketosis occurs normally at varying levels, particularly in children, who may develop ketosis within hours of a meal, in adults during prolonged exercise, and in pregnant and lactating women [22]. Ketosis spares muscle from being broken down for its glucogenic amino acids. It is in fact a protective mechanism for the brain and for general survival. Cahill and coworkers, in their substantial work with the biochemistry of starvation, suggested that more than 60% of human energy needs can be met by ketolysis [32].
Ketosis is associated with acidosis in diabetes because several of the products can form ketoacids [21]. However, the level of ketones in acidosis is far higher than the levels observed in carbohydrate restriction or in starvation. In normal individuals at rest, HB and AcAc are at concentrations below 0.1 mM. After several days of fasting, levels of AcAc rise to about 1–2 mM; HB concentration rises to 5–8 mM [33]. In diabetic acidosis, blood levels of HB are as high as 25 mM [24]."
