Calorie Tracker Guide · 2026-11-14
Verdict
Key to Health: Metabolic AI prices as Free · 4 in-app purchase option(s). Senza: Keto & Fasting prices as Free. Senza: Keto & Fasting is marked for Barcode scanner, Apple Health, Macro tracking. Key to Health: Metabolic AI is not. Editorial scores are 5.4 for Key to Health: Metabolic AI and 5.2 for Senza: Keto & Fasting, on a 10-point scale. That score is not the store rating.
Price
Key to Health: Metabolic AI: Free · 4 in-app purchase option(s).
Senza: Keto & Fasting: Free.
Monthly figure: Key to Health: Metabolic AI $99.99, Senza: Keto & Fasting unknown.
Yearly figure: Key to Health: Metabolic AI $95.99, Senza: Keto & Fasting unknown.
Features that differ
Barcode scanner: only Senza: Keto & Fasting is marked available.
Apple Health: only Senza: Keto & Fasting is marked available. Mentioned in the App Store description.
Macro tracking: only Senza: Keto & Fasting is marked available. Mentioned in the App Store description.
Workout tracking: only Senza: Keto & Fasting is marked available. Mentioned in the App Store description.
Fasting: only Senza: Keto & Fasting is marked available. Mentioned in the App Store description.
Fit
Key to Health: Metabolic AI has no best-fit line.
Senza: Keto & Fasting has no best-fit line.
Where the scores differ
Pricing value: Key to Health: Metabolic AI 4.1, Senza: Keto & Fasting 10. Key to Health: Metabolic AI: 10 - annualised price $95.99/15 (+0.5 if free trial). Senza: Keto & Fasting: 10 - annualised price $0.00/15 (+0.5 if free trial).
Feature depth: Key to Health: Metabolic AI 1.1, Senza: Keto & Fasting 2.3. Key to Health: Metabolic AI: Quality-weighted share of tracked features available (excellent 1.0 .. poor 0.2), x1.6, capped at 10. Senza: Keto & Fasting: Quality-weighted share of tracked features available (excellent 1.0 .. poor 0.2), x1.6, capped at 10.
User feedback: Key to Health: Metabolic AI 7.9, Senza: Keto & Fasting 9. Key to Health: Metabolic AI: Bayesian rating 4.59 (iOS 4.75x2256 + Play 2.72x165, prior 4.3x200) + review stars sentiment +0.15 over 20 reviews. Senza: Keto & Fasting: Bayesian rating 4.72 (iOS 4.78x10816 + Play 4.44x1907, prior 4.3x200) + review stars sentiment +0.45 over 20 reviews.
Maintenance: Key to Health: Metabolic AI 8.8, Senza: Keto & Fasting 1.7. Key to Health: Metabolic AI: Last release 2 days ago (half-life 90d, 70%) + median 16 days between releases (30%). Senza: Keto & Fasting: Last release 332 days ago (half-life 90d, 70%) + median 47 days between releases (30%).
Traction: Key to Health: Metabolic AI 5.6, Senza: Keto & Fasting 6.8. Key to Health: Metabolic AI: log10 of 2421 total ratings (iOS+Play), 1M ratings = 10. Senza: Keto & Fasting: log10 of 12723 total ratings (iOS+Play), 1M ratings = 10.
Coachability: Key to Health: Metabolic AI 5.5, Senza: Keto & Fasting 0. Key to Health: Metabolic AI: Best quality of aiCoach / coachConnection features. Senza: Keto & Fasting: Best quality of aiCoach / coachConnection features.
Who should pick which
Choose Senza: Keto & Fasting if you need Barcode scanner and Apple Health.