FitCalc

GKI Calculator: Glucose Ketone Index

A GKI below 1.0 indicates therapeutic ketosis (used in cancer/epilepsy research). GKI of 1-3 means high ketosis. GKI of 3-6 indicates moderate ketosis. GKI of 6-9 is low ketosis. Above 9 = not in ketosis. To calculate: GKI = blood glucose (mmol/L) / blood ketones (mmol/L). Example: glucose 80 mg/dL ...

Calculate Your GKI

Glucose Ketone Index for metabolic health.

Glucose Ketone Index

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GKI Interpretation

GKI RangeKetosis LevelTypical Use
Below 1.0Highest therapeutic ketosisCancer adjunct therapy, extended fasting
1.0 - 3.0High ketosisTherapeutic epilepsy management, fasting
3.0 - 6.0Moderate ketosisWeight loss, general metabolic health
6.0 - 9.0Low ketosisNutritional ketosis, keto diet
Above 9.0Not in ketosisStandard diet

How to Measure

Blood glucose: Use any standard blood glucose meter. Measure in the morning, fasting, for consistency. Record in mg/dL (US) or mmol/L (international).

Blood ketones: Use a ketone blood meter (measures beta-hydroxybutyrate). Finger-stick, similar to glucose testing. Urine strips are NOT accurate for GKI — they measure acetoacetate, not BHB.

Glucose Unit Conversion

mg/dLmmol/L
703.9
804.4
905.0
1005.6
1106.1
1206.7

Conversion: mmol/L = mg/dL / 18.016

GKI is a research biomarker. It is NOT a diagnostic tool and should NOT be used to make medical treatment decisions. Therapeutic ketogenic diets for epilepsy or cancer should be done under direct medical supervision. Never replace prescribed medical treatment based on GKI readings. This is not medical advice.
Source: Meidenbauer JJ, Mukherjee P, Seyfried TN. The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy for metabolic management of brain cancer. Nutr Metab (Lond). 2015;12:12. doi:10.1186/s12986-015-0009-2

Sources

  1. Meidenbauer JJ et al. (2015) — The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy. Nutr Metab 12:12
  2. Seyfried TN et al. (2012) — Is the restricted ketogenic diet a viable alternative to the standard of care for managing malignant brain cancer? Epilepsy Res 100:310-326

Frequently Asked Questions

What is the Glucose Ketone Index?

GKI is a ratio of blood glucose (in mmol/L) to blood ketones (beta-hydroxybutyrate in mmol/L). It was developed by Dr. Thomas Seyfried as a biomarker for therapeutic ketosis in cancer research. GKI provides a more complete picture of your metabolic state than either glucose or ketones alone. Lower GKI indicates deeper ketosis and greater metabolic shift from glucose to ketone fuel.

What GKI should I aim for?

It depends on your goal. For therapeutic purposes (epilepsy, cancer adjunct): GKI below 2.0. For weight loss and metabolic health: GKI 3.0-6.0 is effective. For general nutritional ketosis: GKI 6.0-9.0 is sufficient. Most people on a standard ketogenic diet will naturally achieve GKI of 3.0-9.0 without extreme measures.

How do I lower my GKI?

Lower GKI by: (1) Reducing carbohydrate intake further (under 20g net carbs), (2) Extending fasting periods (18:6 or 24h fasts), (3) Increasing physical activity (depletes glycogen), (4) Reducing protein slightly (very high protein can raise glucose), (5) Managing stress (cortisol raises glucose), (6) Improving sleep quality. Therapeutic GKI levels (below 2.0) typically require extended fasting or very strict dietary protocols.

Do I need a special meter to measure GKI?

You need two measurements: blood glucose (any standard glucometer) and blood ketones (a BHB ketone meter). Popular combined meters include the Keto-Mojo, which tests both glucose and ketones from a finger prick. Urine ketone strips are NOT suitable for GKI calculation — they measure a different ketone body (acetoacetate) and become less accurate as you become fat-adapted.

Is GKI relevant for cancer treatment?

GKI is a research biomarker, not an approved cancer treatment. Dr. Seyfried's metabolic theory of cancer proposes that cancer cells are more dependent on glucose than normal cells, and that therapeutic ketosis (GKI below 2.0) may inhibit tumor growth. Some clinical trials are investigating this. GKI monitoring should NEVER replace conventional cancer treatment. Always follow your oncologist's guidance.

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