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 had been dabbling with intermittent fasting in a haphazard way until I got the app, trying to go until dinner.. feeing awful, no defined endpoints, no overall vision.. and was finding it tough, demotivating and demoralising, and has given up several times. I found a link to the app on a blog about intermittent fasting and thought I’d have a play with it.. and it’s mind blowing simple.. choose a fast start it, it times it for you.. but that’s just the beginning.. by tracking I’m the fats with a clear goal and endpoint. It allows you to hold on a little linger and go the distance, helping with motivation and will power. The different fasts and predicted end times allow you to plan to help fit fasting in with you life.. and the overall tracker gives you a little reward and inspiration. It’s very well designed and executed, allows you to edit start and end times, and even coped with me fasting across multiple time zones on a long haul flight without any issues! Good work! There also a section with articles and a little of the theory behind the fasting. Overall I’ve found that fasting consistently has helped my body really adapt to it in a way that I just couldn’t do with keto, and I find I’ve got plenty of energy to train and exercise, and trimmed down a little.. is definitely recommend checking it out..!
Simply genius.
roxabelle
I love it. It’s easy to get into, simple to use, and has seriously helped me kickstart my process of slimming down. Just 6 days in to the 16:8 method my clothes fit better than ever, and that is largely aided by having an uncomplicated app like this one to track my progress and keep me motivated. If I forget to start (or finish) recording my fasts I can easily edit them in the app. If I could add one thing I’d love to be able to switch views on the main screen, between counting the number of hours you’ve been fasting for to just showing the time you started and the time you can stop. So at a glance you can see the time itself rather than counting hours - particularly when you’re adjusting your fast period to fit with social activities (I.e. fasting usually begins at 6 pm for me, but that’s when yoga finishes one day a week, so I move it back to half 6 so I can get a light bite in after, and start later the next day). All in all a simply brilliant app, and I’ve been recommending it to everyone. So grateful that this was put together and shared for free 🙌🏻🙌🏻🙌🏻
10 pounds a month for a broken stats dashboard
Lastgerbera
I have done some homework and this app came on top of many articles as the most user-friendly fasting app. However I really doubt that those who reviewed those have used the app for more that several days. While I opted for premium option because I was new to the concept of fasting and felt I needed support, I received only tons of confusion and conflicting messaging from dashboard/ coach and email updates. They all said different things - from 0 fasts done last week to 3/4 are done to congratulations you nailed it - all 4 are complete. I’m talking about the same week progress that was interpreted by app is very different ways. It’s really not well synchronised at all between modules and the coach is just not worth 10 pounds a month, no way!Although I logged tickets with customer support no resolution was provided. Another major disappointment is how male dominated this app is! All videos are done by male experts, who talk about all topics health including breastfeeding. There is confusing advise about how periods work or don’t work with fasting, to the extent that it’s obvious they don’t know and still trying to put just some content out there. And of course no tracking of periods together with weight or fasting to at least give control and awareness to women to see how those things affect each other. I unsubscribed after using for about 6 weeks.
Love this app
Diane67P
This app is so easy to use, so informative. you can adapt the app to how you want to fast with guides on how to fast but ultimately you can do it almost your way! What I also love is the information and knowledge behind the people that have done the videos and the reading material that it’s not cash work it’s research.As a 55-year-old woman in mid menopause that has tried every day on under the Sun, to some success but obviously as our body gets used to the different types of diets this is the only eaten plan which recommends the best foods to eat after a fast doesn’t tell you that you have to eat this or measure that. After a week and a half trying different types of fast well different lengths as one shoe definitely doesn’t fit all I have now lost over a stone and a half!!!So I would recommend this app to everyone, thank you so much for finally a way of eating that we can adapt to every day with or without an a large income. I also love that I have time to plan the meals that I really enjoy rather than panicking trying to eat three or six small meals a day as sometimes recommended.Sorry this is rather long review, and I don’t normally leave them, however I think it’s so important that people understand the knowledge how food impacts your body and can cause massive long-term problems. Sorry this is rather long review, and I don’t normally leave them, however I think it’s so important that people understand the knowledge how food impacts your body and can cause massive long-term problemsThank you again Diane XX
Developer Response
Hi Diane - Thanks for the kind words and glad to hear you're enjoying 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 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.
