# Key to Health: Metabolic AI — Your metabolism, optimized > AI-powered metabolism tracking and personalized health coaching. (iPhone/iPad app by Keyto, Inc..) - Source: https://appshunter.io/ios/app/key-to-health-metabolic-ai/id1441365703 (this page in markdown: same URL + `.md`) - Developer: [Keyto, Inc.](https://appshunter.io/developer/1441274260) - Category: Health & Fitness - Price: Free with in-app purchases - Rating: 4.80/5 from 2,251 App Store ratings · 143 written reviews indexed - Age rating: 17+ - Requires: iOS 15.6 · 44 MB - Languages: American English - Released: 2019-02-08 - Data updated: 2026-08-29 - Monetization: subscription - User reviews in markdown: https://appshunter.io/ios/app/key-to-health-metabolic-ai/id1441365703/reviews.md ## What is Key to Health? Finally understand what's working for your body—no guesswork, no gimmicks. Key to Health is designed for high-achieving, busy people who want to look better, feel better, and optimize their long-term health without spending hours on complex routines. Backed by science. Guided by AI. Built for real life. Our breath sensor gives you real-time feedback on your body's fat metabolism—so you can see what your daily choices are actually doing, not just hope for the best. Pair that with smart AI coaching, and you have a system that adapts to you. What you'll get: • Real-time fat metabolism tracking with our breath acetone sensor • Personalized coaching from Key, your AI health guide • Clear, science-based goals and progress tracking • Tools to build strength and support long-term health • Eat what you love—no restricted foods, no keto required Meet Key: Your 24/7 AI Coach Key learns from your habits, adjusts your plan, and guides you every step of the way. Instant support and personalized guidance, whenever you need it. Grounded in clinical evidence. In a published clinical trial, participants following the Key to Health program lost an average of 10% total body weight over 48 weeks. No fad diets. No extreme routines. No forbidden foods. Just real progress, made easy. This app and breath monitor are for adults 18 years and older. Subscription pricing and terms: Key to Health offers an auto-renewing monthly subscription at $49.99/month to provide you with unlimited access to the Key to Health Premium collection while you maintain an active subscription. Payment will be charged to your Apple Account when you confirm the initial subscription purchase. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current subscription period. Your account will be charged for renewal within 24 hours prior to the end of the current period at the current subscription price. You may manage your subscription and turn off auto-renewal by going to Settings > Manage Subscription on your device after purchase. Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription, where applicable. Read more about our terms and conditions here: Terms of service: https://keytohealth.ai/terms Privacy policy: https://keytohealth.ai/privacy ## Key features - Real-time fat metabolism tracking - AI health coaching - Personalized goals and progress tracking - Strength building tools - No restricted foods or diets ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Keyto Annual Subscription | $95.99 | per year | | Keyto Monthly Subscription | $14.99 | per month | | Keyto 2 Month Subscription | $99.99 | per 2 months | | Keyto 1 Month Subscription | $49.99 | per month | ## What do users think of Key to Health? Overall sentiment: positive **Pros** - 🚀 Easy to use - 👍 Accurate ketone readings - 🚀 Convenient and portable - 👍 Helpful for staying on track with keto - 👍 Motivating and informative app - 🚀 Simple and straightforward **Cons** - 🐛 Connectivity issues - 🐛 Inconsistent readings - 💰 Expensive subscription - 🔍 Limited food database - 🐛 Buggy app updates - 🔍 Lack of customization options **Commonly reported bugs** - App crashes when reaching 100% during measurement - Inconsistent connectivity between device and app - Incorrect weight display in metric units - App stuck in loop during onboarding process **Most requested features** - Add ability to edit or delete recorded readings - Integrate with Apple Health or other fitness apps - Expand food database, especially for non-US users - Provide more personalized coaching and feedback ## Recent user reviews (10 of 143) All indexed reviews: https://appshunter.io/ios/app/key-to-health-metabolic-ai/id1441365703/reviews.md ### 5/5 — Great device and app *2026-07-09, version 4.0.3* Really love this device and app. I wish you’d make a change to the age ratings. It’s on 18+ now so I cannot use it on my phone. Don’t see why this needs to be 18+. Even 16+ would be very conservative. ### 3/5 — Great but… *2026-06-03* This a great little device to measure ketosis. However the app has this fire sound effect after taking measurements that is SO LOUD. I’m trying to take measurements in the beginning of the day upon first waking up, but there’s no way to turn this sound fx off. There is no option to turn it off in the app settings or in apple’s settings. It does not even respond to the volume setting! I should be able to take my measurements without waking other people up. Please allow the option to silence it! ### 5/5 — New design is magic *2026-05-30, version 4.0.3* I have been using Keyto on and off for many years with great results. The new design is super. It was a much needed refresh and it delivers. Excellent product. ### 1/5 — Don’t Bother *2026-05-25, version 4.0.3* This is a scam…I can no longer use my Keyto because they decided to charge $50 a month to use the app. This was free. ### 5/5 — Trends *2026-04-17, version 4.0.1* I don’t have a subscription, so maybe that is why every single day it shows that I it is my first time blowing. It doesn’t show my trend. ### 1/5 — Useless to me since last update *2026-03-31, version 4.0.1* I’ve used the sensor for about a year, and kept a 30 day average of 4-4.8. Since the update, I get a continual battery low indicator (even after 3 battery changes), and mostly get readings of 1. Very annoying that I couldn’t even take a reading after the update without 10 minutes of questions by an AI tool that seems untrained. I’m giving up. It offers no value. ### 3/5 — New Update *2026-03-31, version 4.0.1* The new update doesn’t seem to have been tested. Informational quotes cover the the functional meter when taking a measurement, and the system forces you through and initial questionnaire with no option to skip. ### 5/5 — Easy to use, reliable *2025-11-30, version 3.4.1* Only short coming is the inability to add or edit notes after a reading is recorded in Journey. Also tedious to drill down to see the individual days. The only option at that level in the app is “ cancel “ or “delete”. There needs to be another option, “edit note”. Thanks. ### 1/5 — Keyto data doesn’t since with Apple health *2025-11-19, version 3.4.1* Hands down the worst health data app ever made. Write my keyto score to the health app. Or at least allow me to download my data. Seriously, it’s 2025. Give me my data ### 1/5 — "Generous" 3 months manufacturer warranty! *2025-01-31, version 3.4.1* The device worked well at first, but my Keyto stopped functioning just four months after purchase. I was disappointed to learn that the warranty only lasts three months, which seems questionable. Too many devices stop working past 3 months of use? Unfortunately, this ended up being a waste of money. Given there are no negative reviews on their website is telling as well. ## Frequently asked questions about Key to Health ### What does Key to Health: Metabolic AI do? This app helps you understand your body's fat metabolism in real-time using a connected breath sensor. It provides personalized coaching from an AI guide to optimize your health, track progress, and build strength without requiring restrictive diets or forbidden foods. ### What are the key features of this app? Key features include real-time fat metabolism tracking via a breath acetone sensor, personalized coaching from an AI health guide named KEY, clear science-based goals, progress tracking, and tools to build strength. It emphasizes eating what you love without needing keto or restricted foods. ### How much does Key to Health: Metabolic AI cost? The app offers a monthly subscription at $49.99/month for unlimited access to premium features. Payments are charged to your Apple Account and subscriptions automatically renew unless turned off at least 24 hours before the current period ends. ### Who is this app designed for? This app and its accompanying breath monitor are designed for adults aged 18 and older, particularly high-achieving, busy individuals who want to improve their appearance, well-being, and long-term health without complex or time-consuming routines. ### Can I use this app without a breath sensor? The core functionality of real-time fat metabolism tracking relies on the connected breath acetone sensor. While the AI coaching and progress tracking features may offer some utility independently, the primary benefit of understanding your metabolism is tied to the sensor's data. ## Version history (last 5 releases) ### 4.0.6 — 2026-08-19 • Bug fixes and performance improvements ### 4.0.5 — 2026-08-06 • Bug fixes and performance improvements ### 4.0.4 — 2026-07-09 • Bug fixes and performance improvements ### 4.0.3 — 2026-05-21 • Bug fixes and performance improvements ### 4.0.2 — 2026-05-19 • Bug fixes and performance improvements ## Apps similar to Key to Health | App | Rating | Price | Category | | --- | --- | --- | --- | | [Keto Diet App － Carb Tracker](https://appshunter.io/ios/app/keto-diet-app-carb-tracker/id1406879426) | 4.7 (82,159) | Free | Health & Fitness | | [KetoDiet: Fasting & Meal Plans](https://appshunter.io/ios/app/ketodiet-fasting-and-meal-plans/id575004207) | 4.4 (2,445) | Free | Health & Fitness | | [Carb Manager: Keto & Macro Log](https://appshunter.io/ios/app/carb-manager-keto-and-macro-log/id410089731) | 4.8 (733,332) | Free | Health & Fitness | | [Keto diet app－Low carb manager](https://appshunter.io/ios/app/keto-diet-applow-carb-manager/id1169054597) | 4.6 (61,991) | Free | Health & Fitness | | [MyNetDiary Carb Genius - Keto](https://appshunter.io/ios/app/mynetdiary-carb-genius-keto/id1553449302) | 4.7 (5,093) | Free | Health & Fitness | | [Keto Diet App ⓒ](https://appshunter.io/ios/app/keto-diet-app/id1524415872) | 4.4 (523) | Free | Health & Fitness | ## Related topics [ketone meter breathalyzer](https://appshunter.io/ios/topics/ketone-meter-breathalyzer) · [healthy bytes ai](https://appshunter.io/ios/topics/healthy-bytes-ai) · [metabolic health](https://appshunter.io/ios/topics/metabolic-health) · [nutrimate healthy ai](https://appshunter.io/ios/topics/nutrimate-healthy-ai) · [metabolic health summit 2024](https://appshunter.io/ios/topics/metabolic-health-summit-2024) · [health optimization](https://appshunter.io/ios/topics/health-optimization) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*