3. Increased Ketones in the Blood
One of the hallmarks of a ketogenic diet is a reduction in blood sugar levels and an increase in ketones.
As you progress further into a ketogenic diet, you will start to burn fat and ketones as the main fuel sources.
The most reliable and accurate method of measuring ketosis is to measure your blood ketone levels using a specialized meter.
It measures your ketone levels by calculating the amount of beta-hydroxybutyrate (BHB) in your blood.
This is one of the primary ketones present in the bloodstream.
According to some experts on the ketogenic diet, nutritional ketosis is defined as blood ketones ranging from 0.5–3.0 mmol/L.
Measuring ketones in the blood is the most accurate way of testing, and is used in most research studies. However, the main downside is that it requires a small pinprick to draw blood from the finger (9).
A test kit also costs around $30–$40, and then an additional $5 per test. For this reason, most people will just perform one test per week, or every two weeks.
Bottom Line: Testing blood ketone levels with a monitor is the most accurate way to measure whether you are in ketosis or not.