Best Calorie Tracking App for Intermittent Fasting (2026)

Calorie tracking combined with eating-window timers. Zero serves as the specialized fasting application, while Cronometer excels in calorie tracking with a seamless fasting integration.

Top Pick: Zero Is Our Top Pick for Intermittent Fasting

Zero stands out as our top choice for intermittent fasting. Since IF is primarily a timing method, Zero is the sole app that approaches it from this angle, offering an excellent fasting timer, thorough education about fasting stages, and tracking of mood and biomarkers. The addition of calorie tracking is new and suitable for users who do not require an extensive food database.

For those seeking a single app that can manage both fasting and accurate calorie tracking, Cronometer is a formidable alternative, with its Gold tier providing a fasting timer along with a USDA-compliant calorie database.

What We Tested

We evaluated 6 different trackers over a 30-day intermittent fasting protocol with three participants, each following different fasting methods: one on 16:8, another on OMAD, and the last on 5:2 alternate-day fasting. Each participant logged the same meals and maintained identical fasting periods across all 6 applications concurrently for 7 days, followed by continued primary use in their designated app for an additional 23 days.

We assessed the accuracy of the fasting timer, flexibility of the schedule, speed of eating-window logging, and the ease of switching between fasting mode and calorie logging.

Why Zero Wins for Intermittent Fasting

Three key reasons.

Initially, the fasting timer is the most streamlined in its category. The selection of schedules, preset options, mid-fast alerts, and end-of-fast reflection prompts are all refined. Zero is designed specifically for fasting; other apps merely add fasting features.

Secondly, it provides education regarding fasting stages. Zero indicates when users enter ketogenesis, autophagy phases, and glycogen depletion. This context is valuable for IF users, which competitors often overlook.

Lastly, it includes biomarker tracking. Zero automatically links fasting duration with mood, energy levels, and sleep quality. For users fine-tuning their IF approach over time, this information enhances the ability to improve their protocol.

Apps We Tested

The ranked list appears above. Cronometer is the principled second choice for users wanting a single app that covers both fasting and calorie tracking. Its fasting timer is functional, though not elaborate, and its calorie tracking is the most precise in its category.

MyFitnessPal and Lose It! both offer Premium fasting timers, but they feel more like supplementary features instead of integral components.

Why Eating-Window Logging Speed Matters

A 16:8 intermittent fasting user has 8 hours to log 1,800-2,400 calories, while a 20:4 user has just 4 hours. Shortened eating windows necessitate logging multiple meals quickly, often in one sitting. The application that excels is the one that can manage this density without disrupting the flow.

Cronometer and MyFitnessPal manage dense logging efficiently. Zero’s calorie tracker is not optimized for this, which is why many intermittent fasting users use Zero alongside a different calorie tracker.

Apps We Also Tested But Didn’t Make the List

We evaluated Nutrola during this protocol. Nutrola registered ±1.2% MAPE on DAI 2026 May validation, the best of any tracker, and its photo-first approach suits intermittent fasting users with 1-2 meals daily. The free tier allows for 3 scans per day, accommodating all eating for 16:8, 18:6, and OMAD users without financial pressure. We did not include it as the top choice because tracking for IF fundamentally relies on a fasting timer, which Nutrola lacks. However, it serves as an excellent calorie companion to Zero. For more information, see the Nutrola review.

We excluded Carb Manager (keto-focused) and Noom (cost issues) due to category relevance.

Bottom Line

For intermittent fasting, use Zero for the fasting timer. Combine it with Cronometer (free tier) for precise calorie tracking during the eating period, or utilize Zero’s built-in tracker if you require less accuracy.

For OMAD users specifically, considering the Zero + Nutrola combination is advisable, as Zero manages the fasting aspect while Nutrola tracks meals with superior accuracy within its category.

Intermittent fasting is a timing strategy. Choose a tool that understands this.

The 6 apps, ranked

Quick Comparison

How We Score Apps