How do I calculate my Glucose and Ketone Index?

Trying to calculate your ketone levels? Learn all about the Glucose Ketone Index (GKI) and how to use it for tracking ketosis.

Why do I need to watch my Glucose Ketone Index?

You might already be measuring your ketones to see if you are in ketosis. Did you know adding glucose in the mix provides you a more complete picture?

For example, even with ideal ketone levels for weight loss, high blood glucose levels can affect your health goals and prevent you from receiving the full benefits of ketosis.

The GKI number you strive for depends on your health goal, but generally, a lower GKI is best.

How to calculate my GKI?

To calculate your GKI, test your glucose and ketone levels in a fasted state (at least 2 to 3 hours after eating). To do that, you’ll need:

First, measure your blood glucose levels as described on your blood glucose meter. Then, do the same for your ketone levels, following the directions on the test. Note the results, then use the easy formula below:

The formula is not very complicated: [Blood Glucose Result ÷ 18] ÷ Blood Ketone Result = GKI

IMPORTANT: If you’re not in the U.S. and the glucose reading is already in mmol/L, you don’t need to divide your glucose result by 18.

If you have all your results in mmol/L then the formula is even more simple; Glucose Result ÷ Blood Ketone Result = GKI

What are the factors affecting your GKI?

Many lifestyle and environmental factors can affect your GKI because both ketone and glucose levels change quickly in response to diet, exercise, stress, and environmental conditions. If you’re trying to maintain a low GKI number, keep these habits in mind:

  • Fasting: After eating, it can be pretty tough to stay in a very low glucose-ketone range because there’s a degree of glucose increase. Practicing intermittent fasting can be beneficial for decreasing blood glucose levels, keeping GKI low, and maintaining good health.
  • Nutrition: If your glucose levels are high, eating a ketogenic diet and watching out for hidden carbs can help improve your GKI ratio.
  • Stress: When you’re stressed, hormones like cortisol and epinephrine are released, which can cause blood sugar to rise. To keep that ratio low, focus on daily stress-reducing practices, and try to get plenty of rest.