 Background: Humans naturally produce ketone bodies under daily living conditions. The main ketone bodies are two functioning acids, beta-hydroxybutyric acid 3-OHB and acetoacetate, and the pH-neutral, but odorous, acetone. In the fed state, level of 3-OHB is suppressed to an almost unmeasurable level while, in the fasted state, it rises to 0.1-0.5 millimoles mM. Main regulation of ketone synthesis is the abundance of sugars and resulting adaptations in insulin secretion. Thus, ketone bodies are formed when sugar is not readily available and insulin is suppressed. This picture is, to a certain degree, seen in acute inflammatory states and, indeed, during starvation, where level of 3-OHB increases to 5-8 mM. 