Zero: Fasting & Health Tracker 17+

Weight Loss & Metabolic Health

Zero Longevity Science, Inc.

    • Free
    • Offers In-App Purchases


Stop counting calories and start intermittent fasting with Zero, the world’s most popular fasting tracker and metabolic health app.

Zero maximizes your body’s natural fat-burning ability between your last meal today and your first meal tomorrow. Based on the science of intermittent fasting, we help you extend your natural overnight fast to increase fat burning and accelerate weight loss. By building simple, science-backed habits, you’ll lose weight, preserve muscle, and live better, longer. Best of all, you’ll do this without counting calories, tracking macros, or restricting foods.


Zero Members have lost millions of pounds — and that’s no accident. Featured in GQ, Good Housekeeping, Men’s Health, Fortune, Techcrunch, Women’s Health, The Tim Ferriss Show, The Joe Rogan Experience, and more, Zero is the world’s most popular intermittent fasting app for all skill levels, from those embarking on their first health journey to expert health and fitness coaches.


Zero is a science-backed, evidence-based approach to losing weight and burning fat effectively. In just 28 days, you'll start to see transformative results, beginning with weight loss and extending to better mood and improved energy, all while transforming your relationship with food. By the 3-month mark, you'll have improved your body composition along with metabolic health markers including waist circumference, fat mass, blood pressure, glucose, and insulin. And the best part? You’ll never need another diet again.


The world's most popular intermittent-fasting Timer helps you track your fasts, your progress, and your goals. Start your Timer and stay on target with all the popular intermittent-fasting types, including:

• 13-HOUR FAST, or “circadian- rhythm fast,” based on research by Dr. Satchin Panda (Salk Institute) that aligns your eating window with your body’s internal clock

• 16-HOUR FAST, or the 16:8 intermittent fast, used by celebrities, athletes, and millions of Zero Members to manage weight and improve metabolic wellbeing

• 18-HOUR FAST, or 18:6, for more advanced fasters

• Other popular fasts such as OMAD (one meal a day), the 20:4 fast, and custom prolonged fasts of up to 7 days


Zero has helped millions of Members form new habits and achieve their weight-loss and health-gain goals. In just a few weeks, you’ll shift your metabolism towards burning more fat with real-time tips, personalized stats, and our exclusive Fat-Burning Mode. Discover insights into the changes your body is experiencing, get daily guidance, and break through plateaus with this one-of-a-kind approach powered by the science of intermittent fasting.


Learn the science behind the daily habits that help you succeed on your journey towards weight loss and health gain. Every week, the Zero science team distills cutting-edge health research down to actionable steps and delivers the latest insights on everything you need to know to get and stay healthy. You’re never alone with Zero as your guide.


Stay focused with expert-led, science-backed content, community Challenges, achievements, and more. Zero is your partner for building healthy habits that propel you towards better, lasting health.


Streaks and Badges celebrate your daily progress throughout your health journey, helping you make progress in the short term while achieving your long term health goals.

Download Zero to get started.

Payment for Zero Plus will be charged to your iTunes Account when you subscribe. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. Manage your subscription by going to your Account Settings.

Read more terms & conditions:
Terms of use:
Privacy policy:

What’s New

Version 5.36.0

Thanks for using Zero!
In this release, you’ll find a few upgrades making it easier to log and edit fasts. We’ve also included a number of bug fixes and performance improvements.

If you have any feedback or questions, please contact our Support Team at

Ratings and Reviews

4.7 out of 5
41K Ratings

41K Ratings

Cdourzi ,

No editing?

We have to sign up now and we can’t edit fasts anymore. Going to look for a new app :(

Amyspiglet ,

I love it especially the Apple Watch app 🥰

Love ❤️

Wallacker ,

Was good, once

Hooray, unneeded update to add a pay version. Only reason I chose this app to start with was that it was simple.

Developer Response ,

Hi there, thanks so much for reaching out! To clarify, Zero Plus is an optional premium upgrade. The free Zero app will always be available to you free of charge and there's absolutely no requirement to upgrade to a subscription. If you have any further questions or if there's any way I can further assist please don't hesitate to reach out at ' Best wishes, Michelle

App Privacy

The developer, Zero Longevity Science, Inc., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer's privacy policy.

Data Linked to You

The following data may be collected and linked to your identity:

  • Health & Fitness
  • Location
  • Contact Info
  • User Content
  • Identifiers
  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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