Atomic Fast: Fasting & Diet
Startise Health & Fitness iPhoneiPadiPod touchApple Watch
Atomic Fast: Fasting & Diet is a free Health & Fitness app for iPhone and iPad by Startise. Rated 5.0/5 from 29 ratings. Requires iOS 18.0.
- Rating
- 5.0
- 29 ratings
- Price
- Free
- on the App Store
- Size
- 22 MB
- Age 4+
- Updated
- Sep 21
- 2026 · v1.3.4
Screenshots
About Atomic Fast: Fasting & Diet
Track your fasts through real metabolic phases, then snap a photo of your meal to log calories and macros in seconds — and see exactly how the two connect. Most fasting apps track time; most calorie apps track food. Atomic Fast connects both. Atomic Fast combines intermittent fasting, AI calorie tracking, macro counting, Apple Health insights, and hydration tracking in one app — made for people who already fast and want more than just a basic timer or food diary. FASTING TIMER WITH METABOLIC PHASES Track your fasts with a real-time fasting timer and estimated metabolic phase guidance. Follow your progress through clear visual stages, from digestion and transition to glycogen depletion, fat burning, ketosis, deeper fasting, and autophagy. Choose popular fasting schedules like 16:8, 18:6, 20:4, OMAD, or create your own custom plan. Adjust your goals anytime, and get fasting milestone notifications without the pressure. AI CALORIE TRACKING IN SECONDS Take a photo of your plate. Atomic Fast typically identifies foods in under 5 seconds and estimates calories, macros, and nutrients — like a smart AI calorie counter and macro tracker that actually understands what you ate. You can also log meals by: - Describing what you ate with text or voice - Scanning nutrition labels - Scanning barcodes - Searching the USDA food database - Adding meals manually when needed No more typing one ingredient at a time. BREAK-FAST SCORE The first meal after a fast matters. Atomic Fast scores your break-fast meal from 0 to 100, with practical suggestions on protein, fiber, carbs, and balance for a smoother transition back into eating. MEALS AND FASTS THAT WORK TOGETHER Most fasting apps track time. Most calorie trackers and food diaries track food. Atomic Fast connects both. See how your last meal affects your next fast, how your fasting consistency affects your eating patterns, and how nutrition timing may connect with sleep, recovery, and daily energy. METABOLIC INSIGHTS Atomic Fast helps you spot patterns across fasting, meals, hydration, sleep, heart rate, HRV, activity, and more. Interactive charts and daily insights help you understand habits like calorie trends, macro balance, fasting consistency, and how nutrition timing may connect with sleep, recovery, and energy levels. Daily insight examples: - "Ending eating by 7 PM dropped your sleeping heart rate by 4 bpm last week" - "On high-recovery days you hit your fasting goal 30% more often" Insights are calculated on your device. Your patterns stay yours. DAILY READINESS SCORE Wake up to a readiness score from key health signals: sleep, HRV, resting heart rate, activity, exercise, and respiratory rate. A simple guide to whether today is a good day to push your fast, stay normal, or focus on recovery. APPLE HEALTH AND APPLE WATCH Atomic Fast syncs 24 Apple Health data types: sleep, heart rate, HRV, steps, workouts, weight, respiratory rate, and more. Meals write 11 nutrients plus water back to Apple Health, keeping your nutrition data connected across your favorite health apps. HYDRATION TRACKING One-tap water logging. Smart reminders that fit naturally around your fasting routine. BUILT FOR EVERYDAY USE - Three themes including a signature Deep Purple mode - Two timer styles: Atomic Ring and Classic Ring - Smart notifications for fasting milestones, hydration, meal reminders, and weekly recaps - Awards and streaks to celebrate progress without pressure - Offline-first experience - Privacy-focused design - Apple Watch companion app ATOMIC+ The free version is the real product — fasting tracking, manual food logging, readiness score, daily insights, themes, and 7 AI meal scans per week, all free and ad-free. Atomic+ unlocks: - Unlimited AI meal scans - iCloud backup and data export Available as Atomic+ Monthly, Atomic+ Annual (with 7-day free trial), or Atomic+ Lifetime. Terms of Use: https://atomicfast.com/terms Privacy Policy: https://atomicfast.com/privacy
Ratings & reviews
5.0
29 ratings
What’s new
Version 1.3.4 · Updated September 21, 2026
Fasting hours now count on the day your fast ends, so an overnight 16-hour fast shows as 16 everywhere instead of being split at midnight. Some past daily totals and streaks may shift by a day. Also fixed a few English labels that showed up as code. Thanks for fasting with us!
App privacy
The developer, Startise, reported these privacy practices to Apple.
Data Linked to You
The following data, which may be collected and linked to your identity, may be used for the following purposes:
- Identifiers: Device ID, User ID
- Usage Data: Product Interaction
- Contact Info: Email Address
Used for: Analytics, App Functionality
Data Not Linked to You
The following data, which may be collected but is not linked to your identity, may be used for the following purposes:
- User Content: Photos or Videos
Used for: App Functionality
Alternatives to Atomic Fast: Fasting & Diet
Looking for apps like Atomic Fast: Fasting & Diet? Here are 6 similar apps on the App Store. The highest rated is Fasting Tracker • Easy Fast (5.0/5), and all 6 are free to download.
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Fasting Center
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Easy Fast - Fasting Tracker
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milkberi
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Fasty: Fasting Tracker
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Fasting Tracker • Easy Fast
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WeightFit: Weight Loss Tracker
4.7
| App | Rating | Price | Last updated | Compare |
|---|---|---|---|---|
| Atomic Fast: Fasting & Diet | 5.0 / 5 (29 ratings) | Free | September 21, 2026 | |
| Fasting Center | 4.7 / 5 (22) | Free | Oct 8, 2026 | Compare |
| Easy Fast - Fasting Tracker | 4.5 / 5 (242) | Free | Oct 10, 2026 | Compare |
| milkberi | 4.6 / 5 (248) | Free | Oct 15, 2026 | Compare |
| Fasty: Fasting Tracker | 4.9 / 5 (7) | Free | Feb 15, 2026 | Compare |
| Fasting Tracker • Easy Fast | 5.0 / 5 (8,997) | Free | Oct 11, 2026 | Compare |
| WeightFit: Weight Loss Tracker | 4.7 / 5 (530) | Free | Oct 3, 2026 | Compare |