Ketone bodies - urine; Urine ketones
There are no risks.
Special diets can change test results. For example, a diet low in carbohydrates and high in protein and fat can raise ketone levels in the blood which can then enter the urine.
Some drugs, including glucocorticoids, can cause false positive measurements.
Inzucchi SE, Sherwin RS. Type 1 diabetes mellitus. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 247.