Definition. The urine creatinine test measures the amount of creatinine in urine. Creatinine is a breakdown product of creatine, which is an important part of muscle. Creatinine is removed from the body entirely by the kidneys. Creatinine can also be measured by a blood test.
Ketones are the byproduct of breaking fatty acids down to be burned. Okay, it's a water fast, but we can assume that after 3 days, ketosis is acheived. About 250 grams of fat is about the maximum amount of fat that will be burned daily. I say around 250-300 grams per day.
The latest Dietary Guidelines for Americans recommends keeping saturated fat to less than 10 percent of calories a day. For a 2,000-calorie-a-day diet, that's 200 calories or about 22 grams of saturated fat. Use the Nutrition Facts label to find out how much fat is in the foods you eat.