Fasting, food, movement and recovery in one adaptive plan — with a coach that knows where you are in it.
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More than a fasting timer. Leptin coordinates when you eat, what you eat, how you move and how you recover — one plan that bends when real life does.
A timer that tells you where you are, not just how long it has been. Eight metabolic phases from post-meal to deep ketosis, an eating window that adapts, and a gentle refeed when you finish.
Photograph a meal and Leptin names the foods, portions and macros. Save the ones you eat often, track water and supplements, and get break-fast guidance that suits the fast you just finished.
Over 200 workouts and 1,300 exercises, with movement matched to your fasting state — a walk deep into a fast, strength work when you are fed. Guided sessions count you through every set.
Ask in plain words, or just show it a photo. The coach knows your window, your goals and what you have already eaten today — so you never have to explain yourself twice.
Weight, measurements, streaks and the patterns underneath them — the metabolic rhythm hiding in your own history, with a weekly report that reads it back to you.
Prefer structure? Enrol in a coaching programme and get a day-by-day plan — meals, movement and fasts — that adjusts when you miss a day instead of shaming you for it.
Most of what Leptin does happens in ten-second moments.
Sixteen hours in. Leptin tells you which phase that puts you in, what your body is doing there, and how long until the next one.
Lunch, somewhere new. Photograph the menu and ask what to order. Leptin reads the dishes and answers against your window, your goals and today's intake — not generic advice.
The plate arrives. One photo logs it — foods, portions and macros identified for you to check and correct, not typed in from scratch.
A guided session. Your workout counts itself through — sets, rests and cues out loud, so the phone can stay in your pocket.
The week, read back. What moved, what did not, and one thing worth trying next week.
The coach opens with the questions worth asking right now. Which ones appear depends on the moment — mid-fast is not lunchtime.
Scan a menu
What should I order here?
Can I have this?
Checked before you eat it, not after.
Log a meal
One photo, and it fills in the rest.
Will this break my fast?
Asked against the fast you are actually in.
A growing library on fasting, food and metabolic health, written to cite its sources and to say which population each finding came from — so you can see the evidence behind the advice instead of taking it on trust.
Connect Apple Health or Health Connect and your workouts come across on their own. Reminders can nudge you at the right hour, and everything stays yours — connect what you want, disconnect whenever.
Fasting, meal logging, workouts, goals, measurements and the library come with the app. A subscription adds reminders and the weekly report, and keeps the coach answering beyond its included allowance. Reminders that ring until you stop them need iOS 26 or later.
Leptin is built calm on purpose: no shame, no streaks-guilt, no hardcore diet culture. We explain what your body is doing and suggest what fits — evidence-informed, always respecting that you know your body best.
Leptin will walk you through every hour of it.
Download Leptin for iPhone and Android
