When I first investigated measuring ketones to determine if I was in ketosis I discovered people use two methods: blood measurements and urine measurements. I started with the blood measurements because it was more accurate, but then purchased the urinary strips because they are much less expensive.
- Test Strips are inexpensive ($0.07 per test)
- Useful when starting the ketotic diet as they can be used to determine if ketosis has started or not.
- Results do not accurately reflect blood ketones levels (see below).
- As a person becomes keto-adapted, the types of ketones the body makes will change and the urine test only detects acetoacetic acid. It is possible for someone to have no detectable urinary ketones and still be in ketosis.
- Accurate measurement of blood levels.
- The Nova Max Plus Glucose Meter I purchased was only $12.49
- One has to stick their finger to draw blood for the test.
- Expensive! Test strips for the best meters can cost $5 a test. I picked the Nova Max Meter because the Ketone Test Strips for that model can be purchased for less than $2 a test. It also tests glucose. Those are only $0.20 per test.
Correlations between blood and urine measurements
These values are based on one research study measuring urine and blood in people at the emergency room with suspected ketoacidosis.
Urine ketones scored as + (1.5mmol/L) = blood ketone 0.5 mmol/L (0.1–0.9)
Urine ketones scored as ++ (4.0mmol/L) = blood ketone 0.7 mmol/l (0.2–1.8)
Urine ketones scored as +++ (8.0mmol/L) = blood ketone 3 mmol/l (1.4–5.2)