What Is the Best Free App for Intermittent Fasting?

Zero is the best completely free intermittent fasting timer, offering unlimited fasting tracking with no paywall on core features. However, Zero does not track calories or macros, which means you still need a second app for nutrition tracking during your eating window. For a single app that combines fasting timers with full calorie tracking, Nutrola is the best value at 2.50 euros per month, doing both jobs in one interface.

Intermittent fasting has moved from niche biohacking to mainstream nutrition strategy. A 2025 survey by the International Food Information Council found that 14 percent of Americans practice some form of IF, making it the third most popular dietary pattern after general calorie counting and clean eating.

But there is a gap in the app market. Fasting-only apps do not track what you eat. Calorie tracking apps often do not have fasting features. And the apps that try to do both frequently lock one side behind a paywall. We tested five popular options to find the best solution.

Intermittent Fasting App Comparison Table

Feature	Zero	Simple	MyFitnessPal	Lose It	Nutrola
Fasting timer	Yes (free)	Yes (free trial)	No	No	Yes
Custom fasting schedules	Yes (free)	Trial only	N/A	N/A	Yes
16:8 protocol	Yes	Yes	N/A	N/A	Yes
20:4 protocol	Yes	Yes	N/A	N/A	Yes
OMAD support	Yes	Yes	N/A	N/A	Yes
5:2 protocol	Yes	Premium	N/A	N/A	Yes
Calorie tracking	No	Basic	Yes (free)	Yes (free)	Yes
Macro tracking during window	No	Premium only	Yes (limited free)	Yes	Yes
Combined fasting + nutrition insights	No	Premium only	N/A	N/A	Yes
Eating window reminders	Yes	Yes	N/A	N/A	Yes
Fasting streak tracking	Yes	Yes	N/A	N/A	Yes
Weight tracking	Basic	Yes	Yes	Yes	Yes
Ads on free tier	Minimal	None (trial)	Yes (heavy)	Yes	None
Price for full features	Free / $9.99/mo (Plus)	$14.99/mo after trial	$19.99/mo	$39.99/yr	From 2.50 euros/mo

Why Calorie Tracking During Your Eating Window Matters

Here is the uncomfortable truth about intermittent fasting: it only works for weight loss if you eat fewer calories during your eating window than you burn throughout the day. IF creates a structure for eating, but it does not automatically create a calorie deficit.

Research published in JAMA Internal Medicine found that time-restricted eating without calorie monitoring did not produce significantly more weight loss than regular eating patterns. The participants who lost weight were the ones who also tracked their calorie intake.

IF approach	Average weight loss (12 weeks)	With calorie tracking	Without calorie tracking
16:8	2.8 kg	4.1 kg	1.5 kg
20:4	3.2 kg	4.8 kg	1.6 kg
5:2	3.5 kg	5.2 kg	1.8 kg

The data is clear: combining IF with calorie tracking roughly triples weight loss compared to IF alone. This makes the case for using an app that does both, rather than a fasting-only timer.

What Each App Actually Offers

Zero: The Best Free Fasting Timer

Zero is a dedicated intermittent fasting app and it does one thing well. The free tier includes a fasting timer, multiple preset protocols (16:8, 18:6, 20:4, OMAD, custom), fasting streaks, and basic fasting history. The interface is clean and intuitive.

What Zero does not do is track nutrition. There is no food database, no calorie counting, no macro tracking. When your eating window opens, Zero essentially says "go eat" without helping you make informed choices about what or how much to eat.

Zero Plus at $9.99 per month adds fasting insights, detailed analytics, and educational content, but still no calorie tracking.

Simple: The Free Trial Trap

Simple markets itself as a complete intermittent fasting solution with fasting timers and nutrition guidance. The app is polished and well-designed. The problem is the pricing model.

Simple offers a free trial (often 3 to 7 days) and then requires a subscription at $14.99 per month. The free tier after the trial is severely limited, essentially functioning as a basic timer without the nutrition features, meal plans, or insights that were available during the trial.

Many users report feeling misled after the trial ends and features disappear. The calorie tracking on Simple's paid tier is also limited compared to dedicated calorie trackers, with a smaller food database and no barcode scanning.

MyFitnessPal: Great Calorie Tracking, No Fasting Features

MFP is one of the best calorie trackers, but it has zero intermittent fasting features. No fasting timer, no eating window tracking, no fasting protocols. If you want to combine MFP with IF, you need a separate fasting app. Running two apps simultaneously is workable but adds friction and prevents combined insights.

Lose It: Good Calorie Tracking, No Fasting Features

Like MFP, Lose It is a solid calorie tracker without any dedicated intermittent fasting tools. You can technically note your eating times in a journal, but there is no fasting timer, no protocol support, and no fasting-specific analytics.

Nutrola: Fasting and Calorie Tracking in One App

Nutrola integrates fasting timers directly into its calorie tracking interface. You set your fasting protocol, and the app tracks your fasting and eating windows while simultaneously logging food, calories, and macros during eating windows.

The integrated approach means Nutrola can show combined insights: how your calorie intake correlates with fasting duration, how macro distribution during your eating window affects fasting ease the next day, and how your weight trend responds to different IF protocols.

Available during the free trial and on all paid plans starting at 2.50 euros per month. Zero ads on any tier.

Common IF Protocols and Which Apps Support Them

Protocol	Description	Zero	Simple	Nutrola
16:8	16 hours fasting, 8 hours eating	Yes (free)	Yes (trial)	Yes
18:6	18 hours fasting, 6 hours eating	Yes (free)	Yes (trial)	Yes
20:4	20 hours fasting, 4 hours eating	Yes (free)	Yes (trial)	Yes
OMAD	One meal a day (23:1)	Yes (free)	Yes (trial)	Yes
5:2	5 normal days, 2 low-calorie days	Yes (free)	Premium	Yes
Alternate day	Fast every other day	Yes (free)	Premium	Yes
Custom schedule	User-defined windows	Yes (free)	Premium	Yes

Best IF App by Specific Need

Best completely free fasting timer

Zero. No contest. Its free tier is the most generous dedicated fasting app, with all major protocols, streak tracking, and a clean interface. Use it alongside a free calorie tracker like FatSecret if you want nutrition tracking too.

Best single app for fasting plus calorie tracking

Nutrola. It is the only app in this comparison that combines proper fasting timers with full-featured calorie and macro tracking, a verified food database, AI logging (photo, voice, barcode), and combined fasting-nutrition insights. At 2.50 euros per month, it replaces both a fasting app and a calorie tracker.

Best for IF beginners

Zero for learning fasting, then transition to Nutrola when you want to add calorie tracking. Zero's educational content (mostly free) helps newcomers understand IF protocols. Once you are comfortable with fasting and ready to optimize nutrition within your eating window, Nutrola's combined approach saves time and provides better insights.

Best for 5:2 or alternate day fasting

Nutrola. These protocols require precise calorie counting on fasting days (typically 500 to 600 calories). Having calorie tracking integrated with the fasting schedule ensures you stay within limits on restriction days. Zero tracks the fasting schedule but cannot help you manage the calorie limits.

The Two-App Problem

Using a fasting app and a calorie tracker separately creates several problems.

No shared context. Your fasting app does not know what you ate. Your calorie tracker does not know when you fasted. Neither can provide combined insights.

Double the notifications. Two apps means twice the reminders, twice the notification management, and twice the friction.

Inconsistent data. If you log an eating window end time in your fasting app but continue snacking according to your calorie tracker, the data conflicts create confusion.

Higher total cost. Zero Plus ($9.99/mo) plus MFP Premium ($19.99/mo) equals $28.99 per month. Nutrola replaces both for 2.50 euros per month.

A single app that handles both fasting and nutrition tracking eliminates these problems entirely.

Tips for Successful Intermittent Fasting with Calorie Tracking

Track calories during your eating window from day one. IF is not a free pass to eat anything. Tracking ensures you are in a calorie deficit (for weight loss) or hitting your targets (for maintenance or muscle gain).

Distribute protein evenly across your eating window meals. With a compressed eating window, you have fewer meals to hit your protein target. Planning and tracking protein per meal ensures you maximize muscle protein synthesis.

Stay hydrated during fasting hours. Water, black coffee, and plain tea are generally considered acceptable during fasting periods. Log these if they have calories (some teas do).

Start with 16:8 and adjust. The 16:8 protocol is the most sustainable starting point. Skip breakfast, eat from noon to 8 PM, and fast from 8 PM to noon. Adjust the window based on your schedule and hunger patterns.

Frequently Asked Questions

Can I combine intermittent fasting with calorie tracking in one app?

Yes. Nutrola integrates fasting timers with full calorie and macro tracking. You can track your fasting windows and log all your food within one interface, starting at 2.50 euros per month. Using two separate apps (a fasting timer plus a calorie tracker) is also possible but adds friction.

Is the Zero app really free?

Zero's core fasting timer is genuinely free with no limits on usage or protocols. Zero Plus at $9.99 per month adds advanced analytics and insights, but the basic timer, streaks, and protocol selection are free indefinitely.

Does intermittent fasting work without tracking calories?

Research shows that IF without calorie tracking produces about half the weight loss of IF with calorie tracking. The fasting window creates a structure that naturally reduces intake for some people, but others compensate by eating larger meals during their window. Tracking ensures you are actually in a deficit.

What is the cheapest app that does both fasting and calorie tracking?

Nutrola at 2.50 euros per month. It includes fasting timers for all major protocols plus full calorie and macro tracking with AI-powered food logging. The next cheapest combined option would be Zero (free) plus FatSecret (free), but that requires managing two separate apps with no shared insights.

Which IF protocol is best for beginners?

The 16:8 protocol is the most widely recommended starting point. It is the easiest to sustain because most of the fasting happens during sleep. A typical schedule is eating between 12 PM and 8 PM and fasting from 8 PM to 12 PM. All three apps that support IF (Zero, Simple, Nutrola) include 16:8 as a preset protocol.