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 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 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 do not write app reviews but I’m compelled to for this app. I used this app for 809 days straight! Lost some weight but more importantly it became a lifestyle that I was happy, healthy and proud of having finally been achieved. I stopped fasting due to a medical problem and after a year I decided to go back to my loyal fasting app. I’m aggravated more than anything but also totally bummed. I like looking at all of the badges I had received, the progress I made and my longest streak in anything I’ve done. I was dedicated. I have been trying to log a fast for over 24hrs. I have deleted and redownloaded the app at least 3x. Now I’m forced to use another app. At least I’ve decided that neither are worth paying for at this point. I was poster child for the success that intermittent fasting can bring and Zero was my buddy and right hand in my success. Now I’m forced to use another app. Won’t be paying for the new app and even if zero did work, I feel like maybe it’s not worth it anymore. Is that the trick, I have to pay for it again for me to even use the basic fasting timer? That’s not right! Before I pay for any app (especially expensive ones like this) I have a strict rule for myself that I must use it for 21 consecutive days. I wouldn’t even consider paying for it unless I’ve put in the 21. And you’d think seeing as I used and paid for it for over a year and after not using and coming back that the developers would possibly offer a welcome back deal…nope! So disappointed!!!
Developer Response
Hi there, We're so sorry this unintentional issue occurred! We're working on fixing this however please email us at support@zerolongevity.com and include the email address that is associated with your account and reference # 62449 so our support team can take a look at your account directly. –Team Zero
Works. 30lbs in 2.5 months
reviewer0102030405
I tried keto, I tried them all. Ended up binging and gaining more back quickly. Found fasting and really knocked out the cravings. With Zero it’s really easy to follow your progress without feeling like you’re staring at a clock waiting to eat again. The articles help ease your mind in the beginning knowing that your hunger pangs and other side effects are common and have reasons. Also how to avoid them and get past the fasting wall. I love the timer and how you can count up or down. I count up because I like seeing how far I can push myself within reason. Counting down makes me want to eat as soon as it hits 0:00. The app has some great tracking features and syncs up with apple health so it takes down the data from my smart scale. Nice knowing that I don’t have to manually enter everything every time. A welcomed improvement would be a way to change the theme of the app to keep it fresh or personalized. Different colors etc. this is a small ask for me. Overall I love the app and have lost 30lbs, 6%body fat in 2.5 months. Tbh I haven’t exercised much at all. Just having my body do what it does and use the energy I’ve stored away for years. But now losing the weight of nearly two full size dyson vacuums, I have more energy both mentally and physically that I now crave to get out and do more
Updated: Room for Improvement
Mattiekinsss
21 Nov Update: The developers reached out to me from my initial review and were super helpful and were able to walk me through how to better navigate the app. My lack of understanding how to fully use all the features is why I struggled to change fast settings without saving it as a preset. Due to their amazing response, explanations and helping me fix my complaints deserves 5 stars. It’s definitely worth the subscription and has earned 5 stars in my book.👌🏾 I can recommend this app 100% ⭐️⭐️⭐️⭐️⭐️—————————————————————It’s ok, I love the majority of the features. & unfortunately I forgot to cancel after my free trial. But it’s not worth $70/year. I don’t understand why there isn’t an option to shift or plug in a fast without having to make it a preset. Life happens and I sometimes do an odd hour fast just to get back on track. But that doesn’t mean I want it to be saved as a preset. You should have the option to just put in a fast without being forced to save it as a template. They’re typically one off fasts. The lack of flexibility there is annoying. It’s also odd that it’s not an option under the premium section. If I’m paying to track my fasts it should be a bit more flexible for the price we’re paying. I’ll look for another app that has this simple feature. It’s great aside from that.
Developer Response
Hi there – Thanks for takiing the time to provide this feedback. If you'd like a refund please visit the following link and choose 'Billing & Subscriptions' then 'Request a Refund": https://getsupport.apple.com/productsGood news! There's no need to make it a preset. If you'd like to fast longer than your goal, go ahead and when you've reached your desired duration, tap the end button on the timer. If you'd like to set a shorter goal (1) tap the small number in the circle just above the timer and to the right (2) tap 'Custom Fast' (instead of tapping a space under 'Your Presets') (3) choose the duration (4) tap 'Load Fast' (if not in a fast already) or 'Change Fast'(instead of 'Save As Preset') if no fast is running on the timer. If you'd like help with these items or anything else in the app please email us at support@zerolongevity.com with the details and include reference #68995 and our support team will assist you directly. –Team Zero
Literally life changing!
Msatx
This app has been literally life changing! I accidentally stumbled upon it, just wanted something SIMPLE to log my fasting hours when I first started learning about intermittent fasting but it has sparked my interest in all things related to fasting and health. Im not able to afford paid version and Im extremely grateful that the free version has enough basic information and tracking features to inspire change and at least plant that seed to help people want to learn more, and to want to live with more insight, regardless of economic situation. I was that moron.. the one watching with suspicion while wolfing down pizzas, thought people fasting were just weird food hating extremists. This app has been a revelation, and has been instrumental in opening the door to a new world to me so to speak. It has been invaluable in changing my attitude towards food, fasting, meditation. If you have the means to buy the paid version do it, it will be a small investment for what you get. For me sadly the the price point for the paid version for this and the podcast is not doable but the free version can be very eye opening. Dont just log fasts like I did at first. Dive in and discover everything on the app thats available for free and listen to the podcasts. Fasting and tracking my glucose is now my normal way of life. Grateful.
Small improvements, smoother experience.
This update adds meal sharing and improves reliability across the app.
• Share Your Meals: Fueling strong? Show it off. Text a friend to motivate each other or share on social to inspire others.
• Signup & Onboarding Fixes: Fixed issues that could cause crashes during account creation and onboarding.
• More Reliable Purchases: Improved account setup to ensure subscriptions are correctly linked to your profile.
Version 7.5.1
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, 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
221 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, but access is managed by the developer through in-app controls.
