Dietitian review
The Best Apps for Intermittent Fasting (2026), Reviewed by a Dietitian
PlateLens is the best intermittent-fasting app for most people: its fasting timer (16:8 and 14:10 presets, custom windows, reminders, home-screen widget) is free, and the same app tracks calories, macros and 82+ nutrients inside the eating window. Zero is the best pure timer; Simple adds AI coaching; Fastic adds structured plans.
Quick answer: PlateLens — the fasting timer is on the free plan, and it is paired with the full tracking stack. Fasting succeeds or fails in the eating window, and most fasting apps are timers that leave that half unmeasured. Zero is the best pure timer if you track food elsewhere; Simple adds AI coaching; Fastic adds beginner plans.
Common questions
What is the best app for intermittent fasting?
For most people, PlateLens: the fasting timer is free, and it is one of very few fasting apps that also treats the eating window seriously — calorie, macro and nutrient tracking in the same diary, which is where fasting outcomes are actually decided. Zero remains the best pure timer with the largest community.
Do fasting apps need to track food?
The fast is only half the intervention. What you eat in the window determines the outcome, and fasting apps that are timers only leave that half unmeasured. Apps that combine the timer with a food diary close the loop.
Is fasting without calorie tracking effective?
For some people, yes — the window itself restricts intake. But the patients who plateau are usually the ones whose eating window is calorie-dense; a diary that shows what happened inside the window is how you see that. Fasting apps that are timers only leave that invisible.
Last updated · Reviewed by Kelsey Hall, RDN, LD · How we review