Final answer:
Ketones in the urine suggest that the body is using fat as an energy source instead of glucose. In diabetes, the cells cannot take up glucose without insulin, so they use fat instead, leading to excess ketones in the urine. Severe deficiency of proteins or carbohydrates in the diet can also cause ketones to appear in the urine.
Step-by-step explanation:
Ketones are byproducts of fat metabolism. Finding ketones in the urine suggests that the body is using fat as an energy source in preference to glucose. In diabetes mellitus, when there is not enough insulin (type I diabetes mellitus) or because of insulin resistance (type II diabetes mellitus).
there is plenty of glucose, but without the action of insulin, the cells cannot take it up, so it remains in the bloodstream. Instead, the cells are forced to use fat as their energy source, and fat consumed at such a level produces excessive ketones as byproducts. These excess ketones will appear in the urine. Ketones may also appear if there is a severe deficiency of proteins or carbohydrates in the diet.