Zero is the all-in-one fasting tracker and nutrition app built for real results. Most fasting and weight loss apps stop at simply tracking fasts or calories. Zero connects the full picture — fasting, protein, meals, hydration, and habits — so you actually change your body composition, not just your eating schedule.
Here’s how Zero helps you get there:
• Track your intermittent fasting — Engage timers, streaks, and insights keep you stay motivated and consistent on your entire fasting journey.
• Log meals the smart way — Skip the tedious manual meal entry routine. Snap a photo and get instant macros, protein composition, and clarity on how effectively your meals support your goals.
• Hit your Protein Score — Track your personalized daily protein target that adapts to your weight and goals. Better protein = better satiety, better muscle retention, better weight loss. Zero makes it automatic.
• Complete the equation: Fasting + Protein — Most people fast or track meals. Zero brings them together so you lose weight, protect muscle, and avoid the pressure and guilt of traditional calorie trackers.
• Stay hydrated to power your fasts — Water tracking helps you maintain energy, reduce cravings, and support metabolic function throughout the day.
• Build healthy habits that actually matter — Track movement, sleep, mood, and other daily pillars that reinforce your fasting and fueling routine.
• Challenge yourself — Hit protein targets, maintain fasting streaks, and stay accountable with motivating challenges built around outcomes, not vanity metrics.
• Learn the real science — Understand how fasting, protein, and hydration work together for sustainable weight loss and metabolic health — with insights from leading experts.
• See measurable progress — Watch your streaks grow, your protein consistency rise, and your body composition improve with clean, insightful trend views.
Whether you’re starting out or optimizing an existing routine, Zero gives you the structure, guidance, and clarity most apps miss.
Zero includes a free version and an optional subscription for premium features. A free trial is available.
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: https://www.zerolongevity.com/terms-of-use
Privacy policy: https://www.zerolongevity.com/privacy-policy
Very well-equipped app, nothing too fancy, but, as well as the topic of the app itself (intermittent fasting), it is a surprisingly good solution to keep yourself at bay while fasting. The features that I’ve been missing:- uploading old data from the other device;- being able to leave additional comments to each fast (and maybe other symptoms except for mood, like they do it in menstrual apps);- a bit more information in the “library” section. Otherwise, thank you for the wonderful job you have done with the app!
Best app to fast with
nothing like Messenger
Great simple app design. I mainly use the app as a fasting clock/reminder and sometimes I like to scroll through my monthly summary. Too bad they have recently removed monthly stats from the free version. I don’t use sophisticated features like coach, calories/sleep/activity count so paying $70/year for a fasting calendar is too much in my case. Please consider creating more affordable plan to enable monthly stats.
Developer Response
Hi there - Thanks for taking the time to provide this feedback. If you've been using the app since before Apple's iOS 4.19.0 you should still have access to this feature. If you still don't see this in the app please send us an email with the details at support@zerolongevity.com and include the email address associated with your account (you can find this by tapping 'Me' then tap your profile picture). We'll be on the lookout for your email. – Team Zero
Worse design, still lags sometimes
0xhappery
Great app, loved old design more, it seemed smoother and calmer, don’t love the contrasts of the current one. Apple health data doesn’t sync properly, and text on the fasting circle overruns into the circle. But thanks overall. The best one for fasting out there.
Quick note
notprivate
I think you should add the editing of real hours fasted. Didn’t find such feature. As sometimes you just forget to stop the clock and prolonged hours aren’t real and fair. So ability to quick edit and bump then down would be helpful. Thank you, overall pleasant experience.
Developer Response
Hi there – Fasts can be edited by tapping 'Edit' on the timer just after a fast has been ended in the app or by tapping 'Me' ➝ tap 'See All' just to the right of the 'Calendar' text ➝ tap th date you'd like to edit and use the edit buttons to edit the start/end time of the fast ➝ tap 'Update Fast'. If you'd like help with this please send us an email at support@zerolongevity.com with any details and our support team will assist. – Team Zero
Your fasting companion just got even better.
This update brings a completely redesigned Apple Watch experience, deeper fasting insights, and a few quality-of-life improvements throughout the app.
• All-New Apple Watch App: We’ve completely redesigned the Zero Apple Watch experience with a fresh new look and expanded fasting functionality, making it easier than ever to start, end, and track your fast from your wrist.
• More Detailed Fasting Insights: Explore enhanced fasting zones to better understand what your body is doing throughout every stage of your fast.
• Smarter Logging: The logging sheet is now easier to navigate, helping you quickly find the actions you use most.
• Bug Fixes: Improved the weight chart experience when no data is available and fixed a dark mode issue on the MVV screen.
Version 7.12.0
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 based, for example, on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Provider
Zero Longevity Science, Inc.
Size
249.7 MB
Category
Health & Fitness
Compatibility
Requires iOS 17.0 or later.
iPhone Requires iOS 17.0 or later.
Apple Vision Requires visionOS 1.0 or later.
Apple Watch Requires watchOS 10.0 or later.
Languages
English
Age Rating
16+
16+
This app is rated 16+ with content restrictions.
Some content may be rated higher, and may therefore be restricted and managed by the developer through in-app controls.
