Ideal GKI Ratios for Slowing Glioblastoma Using Keto-Mojo
Target a Glucose-Ketone Index (GKI) of ≤2 during active treatment, with sustained levels ≤6 as a minimum threshold for therapeutic benefit in glioblastoma.
Evidence-Based GKI Targets
The most recent and highest-quality clinical trial 1 demonstrated that maintaining a mean daily GKI ≤6 during chemoradiation was achievable in 83% of patients, with per-protocol patients achieving even tighter control (GKI of 1.88 ± 0.56 during chemoradiation and 2.53 ± 0.86 throughout chemotherapy). This intensive metabolic approach was associated with dramatically improved outcomes: median overall survival of 21.5 months versus 14.7 months in controls, and 3-year survival of 27% versus 7%.
Specific GKI Thresholds
- Optimal therapeutic range: GKI ≤2 (achieved during intensive metabolic therapy phases)
- Minimum effective threshold: GKI ≤6 (associated with clinical benefit)
- Warning threshold: GKI >9.63 may indicate inadequate metabolic response 2
Monitoring Strategy with Keto-Mojo
The Keto-Mojo device has been validated as reliable for measuring both ketones (ICC = 0.968) and glucose (ICC = 0.809), with excellent diagnostic accuracy for detecting nutritional ketosis 3. Calculate your GKI by dividing blood glucose (mmol/L) by blood ketone (mmol/L) 4.
Daily monitoring protocol:
- Measure fasting glucose and ketones each morning
- Calculate GKI using the formula: GKI = glucose (mmol/L) ÷ ketone (mmol/L)
- Track trends over time rather than single measurements
- Aim for consistent readings in the target range
Achieving Target GKI Levels
The successful protocol 1 combined multiple metabolic interventions:
- Prolonged fasting periods (typically 3-5 days initially)
- Time-restricted feeding (eating window of 4-6 hours)
- Strict ketogenic diet (typically <20g carbohydrates daily)
- Calorie restriction (intentional weight loss averaged 17%)
This multimodal approach was necessary to achieve GKI levels in the therapeutic range of 1.88-2.53.
Important Caveats
Guideline Perspective
Major European nutrition guidelines 5, 6 explicitly discourage ketogenic diets in cancer patients, citing concerns about:
- Risk of malnutrition and weight loss
- Lack of proven clinical benefit in controlled trials
- Low palatability leading to insufficient energy intake
- No demonstrated survival advantage in systematic reviews
The 2017 ESPEN guidelines 6 specifically state there are "no clinical trials demonstrating a benefit of a ketogenic diet in cancer patients" and note that pilot trials in glioblastoma "did not" show benefit (though this predates the 2026 trial).
Reconciling the Evidence
The 2026 clinical trial 1 represents the first substantial evidence of survival benefit, but this conflicts with established nutritional guidelines. The key difference is intensity and monitoring: the successful protocol achieved much lower GKI levels (1.88-2.53) than previous attempts, suggesting that inadequate metabolic control in earlier studies may explain their negative results.
Safety Considerations
- Weight loss averaged 17% but normalized BMI in overweight patients 1
- Adverse events were mild to moderate
- Quality of life and exercise capacity actually improved (contrary to guideline concerns)
- Close medical supervision is essential
- Not appropriate for already malnourished patients (BMI <18.5)
Clinical Implementation Algorithm
- Baseline assessment: Ensure BMI >20, adequate performance status, no severe malnutrition
- Initial phase: Implement prolonged fast (3-5 days) under medical supervision to rapidly achieve ketosis
- Maintenance phase: Strict ketogenic diet with time-restricted feeding
- Daily monitoring: Track GKI with Keto-Mojo, targeting ≤2 during intensive phases, maintaining ≤6 minimum
- Adjustment: If GKI >6 consistently, increase fasting duration or further restrict carbohydrates
- Integration: Continue alongside standard chemoradiation and chemotherapy
The evidence strongly suggests that achieving very low GKI levels (≤2) requires intensive multimodal metabolic therapy, not just dietary ketosis alone 1, 7. Simply following a ketogenic diet without fasting, calorie restriction, and tight GKI monitoring is unlikely to achieve therapeutic levels based on the available data 8.