Support

Most answers are below, and in the app under Settings › Help & support, where quick checks can fix reminders, sync and purchases in one tap.

Still stuck? A real person reads every message and replies within two working days.

Ask a question Report a problem Suggest an idea

Or write to support@lean-fast.com. Emailing from the app adds your app version and device automatically, which helps us answer faster.

Fasting and your plan

How do I change my eating window?

Open Plan and tap a day. Drag the handles on the 24-hour dial, or drag the warm arc to slide the whole window. You can copy a day to the whole week, to weekdays or to weekends.

Can LeanFast start my fasts for me?

Yes. Turn on Autopilot in Settings and each planned fast starts as your eating window closes and ends when the next one opens. You can still start, end or change any fast yourself, and skipping a night takes one tap. Prefer to start yourself? Tap Start fast right in the evening reminder.

I forgot to start my fast. Can I fix the time?

Yes. On Today, tap "I stopped eating at…" before you start, or tap Edit start during a fast, and pick when you really had your last bite. Your stages and streak use the corrected time.

Does ending a fast early break my streak?

Not if you stop because you feel unwell: stopping for your health never breaks a streak. For other days, a Streak Shield (2 a month with Prism) keeps your streak going. Ending early is normal; the coach helps you pick up again.

Which programme should I choose?

You don't have to decide alone. LeanFast recommends Spark, Flow or Blaze from your answers, and each one builds up gently over four weeks. You can switch at any time in Plan › Change.

I'm not getting reminders.

In LeanFast, open Settings › Help & support. If the quick check says reminders are off, tap Fix to open Settings › Notifications › LeanFast and allow them. A Focus mode can also silence them; add LeanFast to its allowed apps.

Prism and billing

What's free and what's in Prism?

Programmes, the weekly planner, Autopilot, the timer, widgets, the Apple Watch app, water and weight logging, challenges, levels and badges are all free, forever. Prism adds unlimited Lens scans, all 96 recipes in Kitchen, Coach (a weekly review, Ask Coach, plan nudges and a daily insight), deep insights, ring themes and app icons, progress photos, Streak Shields and custom fasts. You can try Lens and three recipes for free.

How does the free week work?

Monthly and Yearly both start with 7 free days, one free week per Apple Account. We remind you on day 5, and if you cancel before day 7 you pay nothing.

How do I cancel Prism?

Open the Settings app › your name › Subscriptions › LeanFast and tap Cancel. You keep Prism until the end of the period you've paid for. Deleting the app doesn't cancel a subscription.

I paid but Prism is locked.

In LeanFast, open Settings and tap Restore purchases, signed in with the Apple Account you used to buy. On a new iPhone or iPad, that's all it takes. Family Sharing members get Prism too.

Can I get a refund?

Refunds are handled by Apple. Go to reportaproblem.apple.com, sign in, and choose the LeanFast purchase. If something went wrong on our side, email us too and we'll make it right.

Lens

What can Lens read?

Three things: a plated meal, even with several foods on one plate; a product barcode or QR code; and a nutrition label, EU or US format, in most European languages. You don't need to pick a mode.

Lens can't read my label or barcode.

Hold your device about 10–15 cm away, fill the frame with the label and tap it to focus. Good light helps more than getting closer. If it still fails, use Search foods or choose a photo.

Devices and widgets

How do I set up the Apple Watch app?

Install LeanFast on your iPhone, then open the Watch app on your iPhone › Available apps › LeanFast › Install. Your fast, window and water sync on their own, even when your phone is out of range for a while.

Which devices does LeanFast work on?

iPhone and iPad with iOS or iPadOS 26.1 or later, and Apple Watch with watchOS 26. On iPad it works in any orientation, in Split View, in a resized window and with a sidebar. With more room, Kitchen opens a recipe next to the list and Plan opens a day next to your week. On iPhone Duo, the layout adapts as you fold and unfold. To have the same plan and history on every device, create an account.

Open LeanFast once: it refreshes everything. If a Live Activity doesn't appear, check Settings › LeanFast › Live Activities. Widgets update every few minutes to save battery, so a short delay is normal.

Health and safety

What if I feel unwell while fasting?

Tap "Not feeling well?" on Today, or "I don't feel well" in Settings or on your Apple Watch. LeanFast stops your fast, shows simple steps and calls your local emergency number in one tap: it knows the number for 234 countries and territories, and uses 112 elsewhere. If you have chest pain, faint, feel confused or struggle to breathe, call your local emergency number straight away.

How do I connect Apple Health?

Go to Settings › Apple Health. LeanFast can read your height, weight, steps and sleep, and save the weight and water you log. You choose exactly what's shared, and can change it in the Health app › your profile › Apps › LeanFast.

Is fasting right for me?

LeanFast is for healthy adults and gives general wellness information, not medical advice. If you're pregnant or breastfeeding, have diabetes, take medication or have a history of disordered eating, talk to your doctor first. The short safety check when you set up adapts your plan: it can hold it at a 12-hour overnight fast, or switch to a gentle mode with no fasting at all.

Account, sync and privacy

Do I need an account?

No. Everything works on your device without one. An account, made with a 6-digit email code and no password, keeps your plan, fasts, water and weight on all your devices and safe when you change phones.

My data isn't showing on my other device.

Sign in with the same account on both devices, then tap Sync now in Settings. Sync needs an internet connection. Data is stored in the EU.

How do I export or delete my data?

Settings › Export my data gives you a file with everything. Settings › Delete account deletes your account, everything synced to it and everything on this device. When you're not signed in, Delete all data clears this device. Neither can be undone, and your other devices keep what's on them until you delete it there.

Can I use LeanFast in my language?

LeanFast follows your device language: English (US and UK), German, French, Spanish (Spain and Latin America), Italian, Portuguese (Brazil and Portugal), Catalan, Russian, Arabic, Chinese (Simplified), Japanese, Korean, Turkish, Indonesian, Malay, Hindi, Dutch or Polish, including every recipe and coach message. To pick a different language for LeanFast only, go to Settings › Apps › LeanFast › Language.

A note on safety

If you have chest pain, faint, feel confused or struggle to breathe, call your local emergency number right away. In the app, the "I don't feel well" screen shows the right number for the country you're in, and Emergency SOS on iPhone always dials the local one. LeanFast gives general wellness information, not medical advice. See the privacy policy and terms.