What is the GKI? 

This simple equation is little more than a ratio that takes 2 variables into account, glucose and ketones. Typically, as glucose goes up, ketones go down and diseases are invited to enter. What diseases? When GKI is >50 we see increased occurrence of Alzheimers, heart disease, hypertension, weight gain, diabetes and cancer. All the stuff we want to avoid as we age. Keeping your GKI <25 is a great step toward living longer with vitality and great health. This is called “Health Span” and more valuable than simple lifespan. My Dad lived to be 90 so his lifespan was excellent but his Health Span wasn't so great as the last 10 years of his life was fairly limited. I want a better outcome for you and I.


How to measure

To measure your GKI all you need is a simple monitor that measures a finger stick blood drop for glucose and ketones. I use the Abbott Precision but you could also use the Keto-Mojo. Both are reliable. You will need 2 different strips for the device, one for glucose and one for ketones but both can be done at the same time. Here is the equation to use:

  • Glucose divided by 18 = X
  • Divide X by your ketone measure = GKI

           Glucose Level ÷ 18 ÷ Ketone Level = Glucose Ketone Index

The Target
The overall goal is to see a reading <6 as a sign that you are in a moderate level of ketosis. For example, is my glucose was 90 and my ketones were 1.0 then 90/18/1 = GKI of 5. If I fast longer or exercise harder, then it is expected that my glucose will drop and my ketones will rise, provided I am eating a ketogenic, low carb diet. My personal goal is to see my GKI fall below 6 at least 3 times per week. You may not always stay that low depending on how rigorous you stay with your diet plan. I also don’t ever want to see my GKI rise above 25 and in fact if it ever does then my personal goal is to get it below 10 within the next 12 hours through fasting or exercise.

  • <1 = Nearly impossible to achieve and unnecessary for most people.
  • 1-3 = Deep ketosis for the purpose of treating seizure, Alzheimers, cancer, Parkinson’s, chronic inflammatory states.
  • 3-6 = Moderate Ketosis for reversal of type 2 diabetes, obesity and metabolic disorders
  • 6-9 = Low level ketosis for weight loss and health maintenance.
  • >9 = NO Ketosis. Limited value.

When to measure
Glucose Level ÷ 18 ÷ Ketone Level = Glucose Ketone Index

You can measure at any time of day but realize that diet, fasting and exercise will change these readings dramatically. I sometimes measure it more than once per day if I am experimenting with my body’s response to a specific intervention such as fasting or exercise. Checking after a 16 hour fast, after exercise and after meals will give you a wide range of results. Be a student of your body as you are ultimately the architect of your own physiology.

Watch our YouTube video on GKI