Question

Marissa has joined a weight loss program. As part of the program, she regularly submits a urine sample which is tested for ketones. She went to the clinic today, had her urine checked, and was confronted by the nurse who accused Marissa of cheating on her diet. How did the nurse know Marissa was not following her diet?

Answer 1

Ketones are produced when body fat is burned for the production of energy. Normally, ketones should be present in very low amounts, the sample. If Marissa had to lose weight, then she must be following a ketogenic diet, which means less carbs in the diet and more fat and proteins, so that fat-burning state is achieved in the body. This diet also suppresses hunger. It is apparent that the nurse observed fewer ketones in the sample of Marissa, and got to know that she had been eating carbs and hence, was cheating on her diet. 

Answer 2

Ketones get produced when the body burns fat. So if the ketones are too low, little fat has burned. They also can indicate if there is enough insulin to convert glucose into energy.