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Privacy Policy

How SardinesFasting handles your data. Local-first by default, optional Apple Health sync, no account required.

Last updated: 8 June 2026

In short

Your fasting logs, weight, ketones, glucose and notes stay on your device. We do not require an account. We do not sell your data. The only outbound calls are optional: AI coaching (Pro), Apple Health sync, the community feed if you opt in, and anonymous crash reports via Apple's framework.

Data stored on your device

Stored locally (Apple UserDefaults) and never transmitted unless you turn on a cloud feature:

  • Profile: gender, age band, goal, experience level, cycle phase, weight, waist.
  • Fasting sessions: start, end, planned hours, protocol.
  • Daily logs: sardines, water, electrolytes, ketones, glucose, weight, waist, mood, sleep, notes.
  • Preferences: unit system, language, subscription status.

Apple Health (HealthKit) — optional

If you enable it, the app reads weight, sleep and body-composition data and writes your fasting workouts and weigh-ins. This happens through Apple's secure on-device APIs. We never receive your Health data on our servers.

AI coach (Pro) — optional

If you use the Pro AI coach, your message plus a short profile context are sent over TLS to our backend, which proxies the request to an AI provider, returns the reply, and discards the content. We do not store your conversations. We retain only aggregate, non-identifying counters (number of requests, latency) for capacity planning.

Community feed — optional

If you post to the community feed, your post text and a per-install anonymous identifier are sent to our server so the post can be shown to others. No account, email or name is required. You can choose not to post; tracking your own fasts never requires the feed.

Crash reports

Anonymous crash reports are delivered to us by Apple's operating-system framework. We can see stack traces, not your personal data.

Your rights (GDPR / CCPA)

  • Access & portability: Profile → Data → Export doctor-ready PDF gives you everything the app holds, in a readable form.
  • Deletion: Profile → Data → Erase all data wipes your device. Because we are local-first there is generally nothing on our side to delete; for any community post, contact us to remove it.

Children

The Service is not directed to children under 16. Fasting in growing bodies is medically inappropriate.

Changes & contact

We will update this page and the "Last updated" date if our practices change. Questions: privacy@sardinesfasting.com.