Zero is one of the most popular intermittent fasting apps designed to make tracking your eating windows simple, stress-free, and more consistent. With a clean fasting timer, customizable fasting protocols, mood and energy logs, and Apple Health/Google Fit syncing, it gives beginners everything they need without overwhelming features.
The free version includes the core tools most people use daily. The premium plan unlocks deeper insights and advanced analytics for users who want structured habit-tracking. Zero doesn’t offer medical data or nutrition coaching—it’s built for gentle habit support, not clinical analysis.
If you want a lightweight, beginner-friendly fasting app that keeps you consistent without pressure, Zero is a solid choice.
- Simple, beginner-friendly fasting timer
- Clean UI with minimal distractions
- Optional habit-building tools (streaks, reflections)
- Syncs with major health ecosystems
- Free version offers substantial core functionality
- No medical or advanced metabolic tracking
- Premium analytics locked behind subscription
- Sync issues reported occasionally on Android
- Data accuracy depends heavily on user input
- No food logging or nutrition guidance built-in
What Zero – Intermittent Fasting Is (and Isn’t)
Get a realistic understanding of Zero so you don’t expect features it was never built to offer.
Zero is a lightweight intermittent fasting companion app built around one core function: helping you track fasting windows with simple visual timers. It does not prescribe meal plans, diet rules, or caloric targets, making it accessible to beginners who want structure without pressure. The app also includes streaks, reflections, mood/energy logs, and articles curated by Zero’s science advisors.
What Zero Does Offer
Zero provides customizable fasting protocols (e.g., 16:8, circadian fasting, or custom schedules). The timer is intuitive: you tap to start or stop, add notes, and monitor your progress on a clean dashboard. Reflection prompts help you observe hunger patterns, while energy/mood logs offer a subjective record of your experience. None of these metrics are medical, they’re behavioral tools so users can take a gentler, mindful approach rather than chasing strict numbers.
What Zero Does NOT Offer (Important Limits)
Zero is not a medical or diagnostic app. It doesn’t measure blood sugar, ketones, metabolic rate, or provide clinical fasting recommendations. It also does not validate whether your fasting protocol is appropriate for you personally CDC and NIH guidance emphasize that fasting is not suitable for everyone, particularly people with certain medical conditions, during pregnancy, or when taking specific medications (CDC; NIH). These limitations are important so users avoid expecting medical precision.
What Are the Key Features of Zero Fasting?
Learn how Zero’s core tools actually support day-to-day fasting habits.
Smart Fasting Timer + Streaks
The fasting timer is Zero’s main attraction. You choose a protocol, tap start, and Zero tracks your elapsed fasting time with clean visuals. Streaks add light motivation, useful for behavior change but avoid pressuring you. If you struggle with consistency, streak reminders can help without overwhelming you. This cluster is simple but effective, especially for people who dislike cluttered UI.
Insights, Journaling & Mood/Energy Logging
Zero offers optional reflection tools: mood logs, hunger tracking, and lightweight journaling that help you identify patterns across days or weeks. These tools are subjective, not medical indicators but they help users notice triggers (late meals, stress, dehydration). Scientific organizations like the NIH frequently note that self-monitoring is associated with better habit formation, though accuracy is based on user reporting.
Integrations (Apple Health, Google Fit, Wearables)
Zero syncs with Apple Health and Google Fit for basic metrics like sleep and activity. Remember: wearable data is not medical-grade; both the WHO and NIH note that consumer sensors can vary in accuracy by device type and lighting conditions. Still, syncing improves your timeline by helping you understand when late exercise or short sleep affects your fasting experience. If sync fails, you can re-authorize permissions manually, a common fix covered in the troubleshooting section.
Pricing & Plans
Choose the right version without overpaying for features you won’t use.
Free Version
Zero’s free tier includes the fasting timer, streaks, reflections, basic insights, and limited content. For many beginners, this is enough, especially if you’re simply tracking windows without needing deeper analytics or lessons.
Premium Version (Zero Plus)
Zero Plus unlocks advanced insights, fasting graphs, extended content, and richer mood/energy analytics. Pricing may vary by region; instead of quoting numbers that may change, we note that the app typically uses a subscription model with optional trials. Zero Plus is best for users who want structured analytics or guided education, but casual users may prefer the free plan.
Pros and Cons of Zero Fasting App
A clear, unbiased look at where Zero performs well—and where it doesn’t.
Pros of Zero Fasting App
- Simple, beginner-friendly fasting timer
- Clean UI with minimal distractions
- Optional habit-building tools (streaks, reflections)
- Syncs with major health ecosystems
- Free version offers substantial core functionality
Cons of Zero Fasting App
- No medical or advanced metabolic tracking
- Premium analytics locked behind subscription
- Sync issues reported occasionally on Android
- Data accuracy depends heavily on user input
- No food logging or nutrition guidance built-in
What Real Users Say
Understand actual patterns in user experiences beyond isolated comments.
User reviews highlight Zero’s simplicity and visual clarity. Many praise the app for helping maintain consistent fasting habits without guilt or pressure. However, users also mention that premium content may feel limited for the subscription price. Some Android users note intermittent sync issues with Google Fit. Others appreciate Zero’s gentle reminders and subjective tracking tools rather than heavy analytics.
Zero vs Fastic vs BodyFast (Quick Comparison)
| Use-case | Zero | Fastic | BodyFast |
|---|---|---|---|
| Best for | Beginners, minimal UI | Gamified motivation | Structured weekly coaching |
| Key feature | Timer + mood logs | Water reminders, community | Coach plans and challenges |
| Price model | Free + subscription | Free + subscription | Free + subscription |
| Privacy note | Basic permissions; manual export/delete | Community features require caution | Coach data requires profile setup |
Which App Fits Which Persona?
- Choose Zero if you want the cleanest fasting timer with minimal friction.
- Choose Fastic if community support and gamification motivate you.
- Choose BodyFast if you want structured weekly coaching (non-medical).
Installation & Sync Steps
Set up Zero quickly—plus the easiest sync fixes for wearables.
Install on Android or iOS
- Open Google Play or App Store.
- Search “Zero: Intermittent Fasting.”
- Tap Install → Open.
- Create an account or continue as a guest.
- Grant only necessary permissions (notifications, health data, reminders).
Sync with Apple Health, Google Fit, or Wearables
- Go to Profile → Integrations.
- Enable Apple Health or Google Fit.
- Approve read/write access selectively.
- For wearables (e.g., Garmin, Fitbit), rely on their sync into Apple/Google ecosystems.
Troubleshooting
Fix the issues most users face—fast.
Timer Not Starting
- Force close the app
- Restart your device
- Check offline mode settings
- Reinstall if corrupted
Syncing Issues
- Re-authorize Apple Health/Google Fit permissions
- Toggle Bluetooth
- Update Zero + your OS
- Clear Google Fit cache on Android
Notifications Not Firing
- Confirm notifications → Allowed
- Disable battery optimization (Android)
- Re-add scheduled reminders
Safety & Privacy (Health)
Protect your wellbeing and health data while fasting.
Health & Safety Notes (From DISCLAIMER_HEALTH.md)
- Educational only — not medical advice.
- Stop fasting if you feel faint, dizzy, or unwell.
- Consult a clinician if you have chronic conditions, take medications, or are pregnant/breastfeeding (CDC/NIH guidance).
- Apps and wearables are not medical devices. Metrics can be approximate.
- Review permissions, data sharing, and deletion settings.
- Teens, sensitive users, or those with eating-related concerns should seek professional guidance.
FAQs
Get fast answers to common questions.
Is Zero Intermittent Fasting accurate?
Zero is accurate for visualizing fasting time but does not measure metabolic data. Wearable integrations rely on consumer-grade sensors, which NIH and WHO note can vary in accuracy. Use Zero as a coaching/logging tool—not a diagnostic measure.
Does Zero require a subscription?
No. The free version is functional for most users. The subscription adds advanced charts, insights, and educational content. Pricing depends on region and platform.
Can Zero help with weight management?
Zero helps with habit consistency but does not guarantee outcomes. For weight-related goals, consult a healthcare professional. No app can replace personalized medical advice.
Is Zero safe for beginners?
Generally, yes—when used gently. However, fasting is not appropriate for everyone. If you have medical conditions or notice unusual symptoms, stop and consult a clinician.
Does Zero track calories or diet?
No. Zero focuses on fasting windows and behavioral logs. If you need meal planning, try nutrition and meal planner apps.
Conclusion
Zero is a simple, intuitive fasting app that works well for beginners who want to track fasting windows without complicated features. Its clean timer, mood logs, and Apple Health/Google Fit syncing make it easy to stay consistent.
However, Zero is not a medical tool and doesn’t provide metabolic analysis or personalized nutrition guidance. If you prefer structured weekly plans or gamified motivation, apps like Fastic or BodyFast may suit you better.
For anyone seeking a gentle, low-pressure way to build a fasting habit, Zero remains a solid and user-friendly option.
Zero is one of the most popular intermittent fasting apps designed to make tracking your eating windows simple, stress-free, and more consistent. With a clean fasting timer, customizable fasting protocols, mood and energy logs, and Apple Health/Google Fit syncing, it gives beginners everything they need without overwhelming features.
The free version includes the core tools most people use daily. The premium plan unlocks deeper insights and advanced analytics for users who want structured habit-tracking. Zero doesn’t offer medical data or nutrition coaching—it’s built for gentle habit support, not clinical analysis.
If you want a lightweight, beginner-friendly fasting app that keeps you consistent without pressure, Zero is a solid choice.
- Simple, beginner-friendly fasting timer
- Clean UI with minimal distractions
- Optional habit-building tools (streaks, reflections)
- Syncs with major health ecosystems
- Free version offers substantial core functionality
- No medical or advanced metabolic tracking
- Premium analytics locked behind subscription
- Sync issues reported occasionally on Android
- Data accuracy depends heavily on user input
- No food logging or nutrition guidance built-in
User Reviews
