Trendy diets come and go, but intermittent fasting (IF) has proven to be popular and shows some early promise in scientific studies. But while the basic concept is simple (limiting your eating to certain hours or days and intermittently fasting in between), it can be hard to do in practice.
You need to choose a specific IF cadence (there’s the 16:8, 5:2, alternate-day fast, and others), use schedules or timers, and develop the willpower to not break the fast. Not surprisingly, there are a number of excellent apps that can help. Here are the best IF apps for iOS and Android.
Talk to your doctor before starting any new diet, including intermittent fasting.
Simplest Way to Start Fasting: Zero
Zero is a very polished and user-friendly fasting app. It starts by assessing your goals and what kind of eating schedule you currently have, then it matches you with one that isn’t terribly different.
Easy to get started quickly.
Basic fasting is free.
Reporting and statistics is inspiring.
No preset choices for common fasts like 5:2 or alternate day fasting.
The Zero Plus subscription is surprisingly expensive.
The app can send you notifications when it’s time to start and stop your fast, and you can easily track your progress over time, which includes celebrating your fasting streaks and watching your weight change over time.
The app is free with an in-app upgrade to the Zero Plus plan for $10 per month. If your needs are simple, the free version does literally everything you could need and gives you a half-dozen fasting choices. But if you want to build a custom fasting plan, you’ll need to upgrade.
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Best for Experimenting with Fasting Plans: BodyFast
Every step of the way, BodyFast seems to emphasize that you’re not in this struggle alone. The first few screens explain the basics of IF, and the app offers to recommend fasting plans for you based on your goals. BodyFast also has a premium feature called Coach which seems to suggest you’ll get a lot of personalized help.
Dozens of plans and schedules to choose from.
Excellent scheduling and tracking.
Trophies and other kudos for staying on target.
Coach isn’t truly personalized to you.
That’s not really the case, though; the Coach upgrade (which costs $56 per year if you buy an annual plan) simply unlocks many of the app’s premium fasting plans and includes special features like weekly challenges to keep you engaged.
If you have your eye on one of the dozens of advanced plans, you might need to pay the premium, but the app includes a solid selection of a dozen fasts for free. Nonetheless, if you want to try every kind of intermittent fast imaginable, they’re pretty much all just a tap away.
The app keeps you informed about when to fast and when to stop, and the overall interface is polished and easy to follow. Combined with the trophies to build your confidence and keep you on track, this is a compelling fasting app.
Best for Free-Form Fasting: FastHabit
If you want a simple but attractive app that can remind you when it’s time to start your fast and gives you a gorgeous countdown till you can eat again, FastHabit might be for you. It doesn’t know what kind of fast you’re on; you simply specify the number of hours in your fast and if you want a reminder. There’s a snazzy chart that shows your progress and tracks your streaks.
Nifty interface for starting and stopping fasts.
Great progress summary.
Super-cheap upgrade to Pro version.
No built-in fasting plans or schedules.
Most of the good stuff is behind a paywall, but it’s a tiny paywall. While most fasting apps require an ongoing subscription, FastHabit unlocks everything for a mere $3. That’s well worth it; you get enhanced stats, weight tracking, reminders about your upcoming fast, and more. If you like the way FastHabit works, you owe it to yourself to pay for the upgrade for the full set of features.
Best for Uncommon Fasting Plans: Window
Window contains fasting plans you won’t find in most other apps, like the Warrior Diet and the OMAD plan, as well as most of the usual suspects and the ability to craft your own custom fasting schedule and goals. Not only will you get notifications reminding you when the fast starts and ends, but you can also enable notifications reminding you to log your weight and celebrate when the fast period is half over.
Lots of fasting plans including uncommon ones
Full scheduling and reminders.
Weight tracking and water reminders.
No free tier; must pay immediately to try the app out.
And the app rewards you with rich and detailed statistics screens that keep you informed about your progress, streaks, and other trophies.
Unfortunately, none of those things are free. You can install the app for free, but to start using it, you’ll need to pay $3 per month to subscribe to the app. Not sure if you want to pay? You do get a three-day free trial, but you’ll need to remember to cancel your subscription if you decide not to continue.
Best for Journaling: Fastient
You won’t get lost in “feature bloat” with Fastient, which keeps things simple – perhaps excessively so. It’s important to be aware that Fastient doesn’t lean into any particular IF strategy, so it doesn’t matter if you’re doing 16:8 or alternate days, for example. In fact, there’s no scheduling at all; you just need to remember when to start and stop the fast in the app, and then Fastient will track your progress for you. That, in a nutshell, is what Fastient does: It tracks.
Very clean and simple interface.
The app is free and has no in-app purchases.
You can set goals for days or fast duration.
No scheduling to remind you when to start and stop your fast.
It will let you know how long you fasted, what your fasting history looks like, and how many pounds you’ve lost. But this app won’t remind you it’s time to put the food away for the day.
Fastient does give you the ability to leave free-form notes, though, which means you can use the app to journal as you diet. Want to track what you’ve eaten, how you feel, and when you slipped? Fastient records it all and lets you review it at any time using the ridiculously simple three-tab interface.
Best for Community Engagement: Life Fasting Tracker
Life Fasting Tracker is one of the most full-featured apps we’ve seen. It’s packed with features in the free version, and the Life+ subscription (which costs $3 per month) takes it up a few notches even further.
Community circles.
Library of article and videos on health and diet.
Opportunity to chat with professional coaches.
Many of the best features are only available after upgrading.
But before we get to that, Life Fasting Tracker not only tracks your fasting, but it syncs with your Fitbit and logs data like weight, waist size, glucose levels, and ketones (if you’re on a keto diet, by the way, this is the tracker for you, because it leans into ketone level tracking pretty hard).
But the app has so much more, like an active in-app community. Vora, which also has a built-in community, could learn a lesson from Life Fasting’s easy-to-use community circles. There’s also a library of educational videos and articles, as well as the opportunity to chat one-on-one with coaches on topics like weight loss, exercise, diet, cancer support, and more (for $15 per 30 minutes).
And if you upgrade to Life+, you get the opportunity to create custom schedules with reminders, choose from a library of IF routines, and more.
The Most Social Fasting App: Ate
Not a traditional fasting app, Ate is a food photo journal that you can share on social media with friends, diet buddies, and coaches. This is great for anyone who enjoys working through diets by talking and sharing. To use the app, you take a photo of your meal and indicate whether the food was “on path” or “off path.”
A novel approach to managing a diet and fasting.
Fast and simple food photography.
Indicating whether the meal was on or off path is a good way to hold yourself accountable.
No fasting plans or scheduling.
You can add notes and write about how the fast is making you feel; as soon as you do, a timer starts, and it tracks the length of time until you snap the next photo. As long as you are diligent about photographing your meals and snacks, you’ll be able to track your fasting periods.
All that is free. It costs $30 per year to go premium which adds a handful of extra features, like the ability to reuse photos, track drinks, and track activities as well. The premium features are a work in progress, as the developer considers the app to be in beta, and rolls out new features to the premium subscribers first.
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