What is the normal acetone/ketone value in urine?

The normal value for acetone or ketones in urine is indeed negative. In a healthy individual, the body typically does not produce ketones in significant quantities, as these are byproducts of fat metabolism and usually only appear in the urine under specific conditions, such as prolonged fasting or uncontrolled diabetes.

When the body is functioning normally and relying primarily on glucose for energy, there will be little to no ketones present in the urine, leading to a negative reading. The presence of ketones, whether reported as trace, small, or large, indicates that the body is utilizing fat for energy, which is not typical for a non-fasting, non-diabetic state. Therefore, the negative result is indicative of a healthy metabolic state regarding carbohydrate usage and overall energy balance.