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
This is truly the best fasting app I used so far, and I can honestly say that with every new update Zero is getting even better. As an app it has an edge over the others I have downloaded and used over time. Now, I only use Zero as the companion to my IF lifestyle.Few recommendations for future updates perhaps that I would suggest would be:- Addition of the also very popular 14/10 IF regimen (even if there is the custom fast option)- Addition of an "eating" window timer (both windows are equally important) (fasting & feasting timers)- Addition of the different stages induced biologically and physiologically by the human body during fasting, at different time frames, backed up by the latest science on the matter (i.e. displayed in real-time on the fasting timer during a fast)- Improved/varying viewing/sorting option for the history journey tab (e.g. calendar like viewing, or in rows, etc)- A good tip a day, keeps the doctor away (e.g. fun fact, helpful fact, fasting or eating fact, motivational message) displayed after saving each completed fast (for example)
Page to ask you to subscribe appears everytime you open the app. Do not bother starting on this app.
llAnonymousllReviewer||
Updated 24 Oct 25Seems this app is running out of funds and most likely will end soon. They are desperate enough to put a full page notification to ask you to subscribe EVERYTIME you open the app. Stay away from this app!!Apr 25:Once your iPhone is in airplane mode, it does not even allow you to load your app to start or end a fast. It seems they want you to be logged on possibly so that they can extract data from you while you use their app and the only way is to ensure you have internet connectivity while using their app. It seems they are finding ways to generate revenue besides trying to get you to subscribe. It has gone even worse and as of version 5.30.0, it forces you to accept a trial because there is no exit option. And if you forget to unsubscribe, an annual fee of more than $100 will be charged. Beware, Zero is fast becoming a scam and it seems to indicate they might be desperate financially to resort to these measure. Furthermore, even though I’ve already subscribed to the normal ad free version, every time you start a fasting window, it annoyingly prompts you to subscribe. This is still going on with the latest version 5.30.0. Do not believe the developer response to this review.Update: 15 May 24. Requires you to put in your date of birth, invading privacy.
Developer Response
Hi there — Thanks for reaching out. While we work hard to support an ad-free version of Zero for most users, we do rely on some paid subscriptions to maintain operations for our greater community. If you have questions, feel free to contact our support team at support@zerolongevity.com. We'll be on the lookout for your message. —Team Zero
The Best App
Anor29
I've been using this app for almost 2 years already. Have changed phones but continue to use it. Though I didn't purchased the premium, the free is already worth it. I can edit whenever I missed updating it and that makes it easier for me to track my fasting cycle. Hopefully the price will be more affordable soon. Thank you 😄😄
Decent fasting app
ruthie loke
I’m using the lite version. The UI is intuitive and pleasant. It does as supposed - a fasting timer with customisable timing plans. I would like it more if there was a built-in forum where we may connect with others who are also on IF. I would prefer that viewing the fasting streak be made optional, as IF is a lifestyle and it’s okay to break your streak. Your body still reaps the benefits. A streak shouldn’t be especially celebrated cos not everyone is trying to achieve a streak. The first time I broke mind I felt demoralised but reminded myself that it’s ok. I know it sounds silly, but I think for the IF protocol to be made into a lifestyle, the narrative surrounding it matters.
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 has an age rating of 16+ with content restrictions.
Some content may be rated higher, and may therefore be restricted and managed by the developer through in-app controls.
