No. Your fasts, settings and coaching all stay on your iPhone. There are no accounts, no analytics and no servers. See the Privacy Policy.

The coach uses Apple Intelligence, so it needs an iPhone that supports it, with Apple Intelligence turned on in Settings. Without it, fasting tracking, the Live Activity and chat still work, but the coach won't send its own nudges. Also check that notifications are allowed for Fasting Coach in Settings → Notifications. The coach stays quiet during your quiet hours.

Hours fasting : hours eating. 16:8 means a 16-hour fast. To change your plan, tap your plan in Profile, or use − and + to set a custom length.

If you turn it on, it reads steps, active energy, sleep and workouts so the coach can match your day. It only reads your Health data and never writes to it. You can turn this off anytime in Settings → Privacy & Security → Health → Fasting Coach.

Yes. Try "Check my fast in Fasting Coach" or "When can I eat in Fasting Coach". You'll find all the shortcuts in the Shortcuts app.

Tap Start over at the bottom of Profile. It erases everything, and so does deleting the app.

No. Fasting Coach offers lifestyle support, not medical advice. Talk to a doctor before fasting if you are pregnant or breastfeeding, have diabetes or take blood-sugar medication, have a history of eating disorders, take prescription medication, or are under 18. Stop fasting and seek help if you feel unwell.