Atomic Fast: Fasting & Diet

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In-app purchases

About this app

Snap a photo of your meal to estimate calories, macros, and nutrients in seconds. Track your fasts. See how your eating patterns, hydration, sleep, and activity connect over time.

AtomicFast combines intermittent fasting, AI calorie tracking, macro counting, Health Connect 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, deeper fasting, and autophagy. Tracking your fast is easy, zero hassle.

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. AtomicFast 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 just to understand what you ate.

BREAK-FAST SCORE

The first meal after a fast matters. AtomicFast 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. AtomicFast 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

AtomicFast 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.

HEALTH CONNECT INTEGRATION

AtomicFast syncs with Health Connect to read sleep, heart rate, HRV, steps, workouts, weight, respiratory rate, and more.

Meals write nutrients plus water back to Health Connect, 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

ATOMIC+ SUBSCRIPTION

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
- Google Drive backup and data export
- Full nutrition insights
- Premium fasting and wellness features

Available as Atomic+ Monthly, Atomic+ Annual (with 7-day free trial), or Atomic+ Lifetime.

Ratings and reviews

The camera meal logging is genuinely impressive, not flawless but saves so much time compared to typing everything manually. The fasting phases are what keep me going when I feel like breaking early. Readiness score took some getting used to but now I check it every morning before deciding how long to fast that day. Only gripe is the free version is pretty limited for the AI scanning, you'll probably end up subscribing. But honestly worth it if you're serious about this stuff Best fasting app!

Atomic Fast is a great app for tracking intermittent fasting and building healthy habits. The interface is clean, simple, and easy to use. It helps me stay consistent with fasting by tracking fasting hours, meal timing, and daily progress. The reminders and motivational features are very useful. Perfect for anyone who wants to improve metabolism and maintain a healthier lifestyle. Highly recommended!

Atomic Fast does a great job balancing fasting and nutrition tracking. I like being able to see my fasting progress alongside meals and hydration in one place. The interface is clean, responsive, and visually appealing, which makes me want to keep using it every day.

What’s new

• Improved onboarding input validation — display name, date of birth, and target weight are now properly validated with safety guardrails
• Portrait orientation lock on the welcome screen for better experience on smaller devices
• Better handling of partial Health Connect permissions
• Performance improvements to the timer dashboard
• Stability improvements and bug fixes