A patient's urine sample tests positive for both glucose and ketone bodies, indicating a severe case of Diabetes mellitus. The appearance of ketone bodies in the urine is primarily the direct result of an abnormally high rate of which of the following metabolic processes?

Step-by-step solution

In Diabetes mellitus, due to insulin deficiency, cells are unable to adequately take up and utilize blood glucose for energy. To meet energy demands, the body shifts to the breakdown of lipids. This excessive lipid breakdown produces ketone bodies as a byproduct, which accumulate in the blood and are excreted in the urine (ketonuria). Breakdown of glycogen or proteins does not directly produce ketone bodies. Answer: Breakdown of lipids