Which condition is least likely to show positive ketones in urine?

In the context of urinary ketones, overhydration is least likely to show positive ketones in urine because this condition typically involves an excess of body water, diluting substances in the urine. Ketones are produced when the body breaks down fats for energy, which typically occurs in states of fasting, diabetes, or excessive alcohol intake. In overhydration, the body has adequate levels of insulin and glucose, reducing the need for fat metabolism and subsequently decreasing ketone production.

Diabetic ketoacidosis results from insulin deficiency and leads to elevated blood glucose levels, encouraging the body to utilize fat for energy, thus producing significant amounts of ketones. Similarly, alcoholic ketoacidosis stems from high alcohol consumption, which affects carbohydrate metabolism, leading to ketone production as the body tries to compensate for hypoglycemia. Starvation initiates a metabolic state where the body uses fat stores for energy due to a lack of incoming calories, also resulting in ketone production. In contrast, overhydration does not lead to ketone production as the body is not in a state of fat metabolism.