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 across your entire fasting journey.
• Log meals the smart way — Skip the tedious manual meal entry routine. With Zero Plus, snap a photo and get instant macros, protein composition, and clarity on how effectively your meals support your goals. Your first meal logs are on us, so you can try it before you subscribe.
• Hit your Protein Score — Zero Plus tracks a 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 with Zero Plus 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 is not a medical device and does not provide medical advice, diagnosis, or treatment. Always consult your doctor or qualified healthcare provider before making any changes to your diet, fasting routine, or health regimen.
Zero is free to download, with fasting timers, streaks, weekly trends, expert articles, and challenges included. Zero Plus is an optional subscription that unlocks photo meal logging and your Protein Score, water tracking, custom fasts and saved presets, Fat-Burning Mode, the mood journal and daily habit insights, premium articles and Plus-only challenges, and monthly, yearly, and correlated charts. A free trial is available.
Payment for Zero Plus will be charged to your Apple 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 in 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
I’m really enjoying the app and think the UI/UX is great so well done. As a regular user, I have a couple of points of feedback, basically I think the app needs to be made a bit more engaging1. Can new challenges please be introduced from time to time? The current challenge list is fine but it’s too limited and could use some more variety 2. Can some level of gamification be introduced? Maybe you can do this with challenges only, but ideally stuff like long streaks/fat burn length etc should be rewarded through achievements etc Overall though, really enjoying this as a pro user. Getting slightly bored now after a couple of months, and there should be more of things above encouraging regular users like me to renew.
Not meeting my (very basic) needs
moosius_maximus
All I wanted was an app that would let me log fast times and gave me some helpful information about fasting. This app has failed on both fronts (despite my subscribing to zero plus):1) my main interest is in logging fast times, which it does. However when I end a fast, it shows me an “eating window” which according to it has been running for 123 hours and it therefore says I should start fasting again immediately. If they know when I started and stopped fasting, they don’t need any more information to work out my eating window. This is literally the point of the app and it’s really disappointing that they can’t even get this right. 2) most of the info content I have seen seems to push one towards longer and longer fasts which was never my goal. I know some people are interested in fasting for days and weeks but that’s not my objective and I would prefer to have more content around 16:8 or circadian rhythm fasts which are more what I’m interested inI also wanted basic things like tracking my fasts against activity during the day and hours of sleep, which zero only offers if you subscribe to the paid package. In my opinion, this stuff shouldn’t even be paid for, but even if they want to charge for it, it is highly overpriced in my opinion. I will not be renewing my subscription.
Developer Response
Hi there — Thanks for providing that feedback. If there is anything we can do to help here, please contact our support team at support@zerofasting.com and reference #47097. We'll be on the lookout for your reply. —Team Zero
You can skip PRO version
Kjoz3009
I was a free user for an year and was intrigued to find out what additional benefits the app offers for PRO version. However, I can tell you, if you are a free user continue to be so. Don’t bother to pay for PRO. You are supposed to get a coach in PRO but I am still waiting ( searching ) for that coach in the app. The app does not offer a whole lot for PRO( to put things in perspective, I am a Fitbit Pro user and the benefits that one gets being PRO FB user are pretty exhaustive). In that context i was thoroughly disappointed. You get articles to read ( I don’t enjoy reading long articles on phone so I skip most of them) some videos to watch but that’s about it. I think the developers need to really offer something unique to hook paid users to the app. That wow factor is completely missing.
Developer Response
Hi there — Thanks for providing that feedback and sorry you're disappointed with Plus. If you'd like help with a refund request or if we can help with anything, you can contact our support team at support@zerolongevity.com and reference #59031. We'll be on the lookout for your reply. —Team Zero
Meal and liquid inputs missing
Rishbans
I love the app and it's UI... Very sharp and crisp... What I miss is if I can log my god and liquid intake also... Other apps offer that... That too in free version... So that winter fasting and otherwise also one can track their intake details also... Correlating it with other health data would give more insights.. Don't want to loose the app for these features to competition... Let me know if these are available features Keep up the good work 👍
Developer Response
Hi there and thanks for the great feedback! This is a great suggestion, and we'll evaluate adding food and liquid intake for a future version of the app. If you'd like to share any other suggestions or feedback, you can reach-out anytime at support@zerofasting.com. Look forward to hearing from you!
More ways to make Zero yours — and share it with friends.
This update brings more flexibility to your daily experience, a new way to share Zero, and thoughtful improvements throughout the app.
• Share Zero with a Friend: Health goals are better with a little accountability. Invite a friend to try Zero right from Settings, and when they join through your link, they’ll get a 30-day free trial of Zero Plus.
• A More Flexible Fasting Timer: Choose between a full or compact timer depending on what you want to focus on. Keep fasting front and center, or free up space to see more of your daily progress.
• A More Cohesive Zero: We’ve refined onboarding and updated buttons and other interface elements throughout the app for a smoother, more consistent experience.
• Logging Improvements & Bug Fixes: We’ve made more of your most-used logging options accessible at a glance and fixed an issue with date of birth selection for some returning users.
Version 7.14.1
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
249.3 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.
