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
I have been using plain old Zero happily and successfully for a few weeks. I was sent an email with a discount offer to purchase Zero Plus due to Black Friday. The link took me to the APP and a page that said ‘oops something went wrong- refresh’. Reaching out to Big Sky Health informing them of the issue, they responded to the first email with a custom made response (very thankful because this is rare) with assistance that unfortunately failed. Upon writing back (complicated by time zone separation) for further support the issue has now been resolved by uninstalling and reinstalling the APP. I’ve persisted because even prior to the full suite of the APP features being available to me this suits my personal requirements for IF and provides useful data points. IT have provided ongoing support and are happy to troubleshoot to ensure a good user experience. I’m really looking forward to using the paid version to enhance my fasting. Being an avid follower of Peter Attia for many years, his association with this APP meant it was my first choice when needing an IT fasting tool. The APP is there to lean on too when in the middle of a fast the going gets tough.
Developer Response
Hi there – We're sorry to hear about this issue with the Black Friday/Cyber Monday event. I see our team has been assisting with troubleshooting the issue in ticket # 26971 and you were able to access the Black Friday/Cyber Monday page in the app. The team will continue to follow up with you through resolution thanks for your patience and understanding. ~Team Zero
Fantastic tool
Sanjuro2
The new update took a few minutes to get use to but easily grew on me. It is more pleasant to look at and easy to browse thru. The badges section is a welcome change and serves as additional encouragement for users. The weight goal, though has no bearing on me, also will serve as an encouragement for first time users. I would like see more articles and videos in the learn section. What’s already there, I think, appeals to people with no science background; easy to understand and well explained without having to google every sciency scientific word in the articles. Thank you, Zero Team. Fantastic tool and fantastic work!
My Fasting Record
nnnnzzzzeeeerrrr
Hi I’ve been fasting only for a short time so trying 16/8 hours but thinking I will extend the fasting time very soon. Love this app as I can see everything very quickly and I understand exactly where I am and how I am succeeding to reach my goals. Am in Ketosis according to my strips and feeling great! Monday morning is weigh in time so I just know I’m going to be down....even just a small amount is special for me. Lost 8kg so far maybe 5kg to go. Subject to how I feel and look. I’m relaxed and enjoying my adventure, first time I’ve been so relaxed while loosing weight! This is an add on, as for some reason the original didn’t get sent! I’m only having one problem and that is my iPad and my iPhone are not working in tandem with this app. I’m a 75y young person but I need help to get my full potential and 100% use of the app. I’m finding it a nuisance to have to go from each place to update and use my zero app and it’s so upsetting! I’m hopeful that someone will be reading this report and then let me know how to fix it!
Bait and Switch online reviews.
Scouty-lugs
If there’s one thing I really hate it’s feeling like I’ve had the old bait and switch. Dozens of online reviews talk about a no cost basic plan, recommending this as a good way to trial the IF habit before deciding if you want to pay for the upgrade, many many reviews saying they are happy with the free version… but surprise surprise, there’s no option for a free plan! Just a one week free trial and then billed for a whole year. One week! IF is a long term lifestyle change that is bound to have some starting issues - what the hell am I going to learn and appreciate in a week? Is this a new thing only having paid plans? Is it reviewers getting kickbacks? Because it’s NOT CHEAP and I’m on a pension. All I feel right now is that the reviews were paid promotions and the app is a Bait and Switch scam to take a yearly fee before I even know if I’ll stick to it. I’ll give it a couple of days so I’ve got an idea of what’s included before finding a free alternative. Leaves a very bad impression. Oh well.
Developer Response
Hi there - We offer a free trial so that access to the full scope of the Zero can be experienced, such as Personalized Fasting Zones, exclusive content and Challenges, advanced data and statistics, and more. To exit the trial offer screen and proceed to the free version of Zero, tap the 'X' in the upper right corner during the free trial prompt. If the "X" to exit does not display for you or if you have further questions, please contact our support team at support@zerolongevity.com and include reference #65607 and our support team will assist. If you opt into a trial, upon authorization, a 1-sentence term is displayed about canceling the trial, and upon cancellation within terms, upon expiration, the free version will be available. –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, for example, based 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
Seller
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 Classification
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.
