Privacy Policy

1. Introduction

A single consent screen is shown at entry. The app uses the general wording “our AI service providers abroad”; the provider names are listed here in this policy. Acceptance of the Terms of Use and Privacy Policy and explicit consent to processing health data such as weight, fasting, meals and steps to prepare your plan are required to use the app. AI processing (sending content to our AI service providers abroad for meal analysis, menu scanning and Momo Coach), and crash reporting and anonymous usage analytics are optional. “Accept and start” enables the optional permissions, except an existing user’s previously explicit refusal of AI. “Choose and continue” starts optional switches off. Acceptance includes your declaration that you are 18 or older. You may close the app if you prefer not to accept. The accepted version, server date, language and permission choices are recorded on your account; guest or offline choices sync when a session and connection become available. You may withdraw optional permissions in Settings → My permissions. Turning AI off stops new coach processing; earlier encrypted audit records remain for the periods and purposes in Section 6.3. You can use account deletion to end required processing. Photo/route publication and leaderboard participation remain separate switches at the point of use; HealthKit/Health Connect and notification system permissions are managed separately.

Only Fasting ("we", "us", "our") is committed to protecting your privacy. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our mobile application ("App").

By using the App, you agree to the collection and use of information in accordance with this policy. If you do not agree with this policy, please do not use the App.

2. Data Controller

For any privacy-related questions or to exercise your data rights, please contact us at the email address above.

3. Data We Collect

3.1 Information You Provide

Apple Health / Health Connect: Health integration is optional. With the read permissions you choose, the App can read supported steps, active energy, workouts, weight, height, sleep, and resting heart-rate data. Read/sync and write/export are separate in-app controls. Logged meal energy and macros, water, and manually entered weight are written to Apple Health / Health Connect only while the account-level “Write to Apple Health” (iOS) or “Write to Health Connect” (Android) control is on and the corresponding system write permissions are granted. You can turn either control off in the App and revoke system access at any time in iOS Settings ▸ Privacy & Security ▸ Health or in Health Connect on Android. We do not sell Health data or use it for advertising. If the AI-processing setting is enabled, the premium weekly digest described in Section 6.1 can include summaries derived from Health data and is sent to Google Gemini.

3.2 Information Collected Automatically

4. How We Use Your Data

• Provide Services: Track your fasting periods, hydration, and progress
• Provide Movement: Generate rule-based movement sessions, apply the feature's stop, rest, and consult paths, and show your session history
• Sync Data: Keep your data synchronized across devices when you create an account
• Send Notifications: Remind you about fasting start/end times and hydration
• Process Payments: Handle premium subscription transactions
• Improve App: Analyze usage patterns to enhance features
• Customer Support: Respond to your inquiries and requests
• Legal Compliance: Meet legal obligations and protect our rights

5. Processing Grounds and Product Controls

Existing stated grounds and the controls currently implemented in the App

6. Third-Party Services

We use the following third-party services to operate our App:

Optional Meta advertising measurement on iOS is separate from usage analytics and health consent. Only if you allow tracking in the iOS prompt, the Meta SDK receives the device advertising identifier (IDFA) and basic install, app-open and session events to measure and optimize Only Fasting ad campaigns. App activation also sends device model, OS and app version, language/locale, time zone, screen size, carrier/network information (including IP address), and the SDK's own anonymous app-install ID. The recipients are Meta Platforms Ireland Ltd. / Meta Platforms, Inc., with processing in Ireland and the USA, including outside your country. Only Fasting does not pass meal photos or text, barcode searches, weight, fasting, Apple Health / Health Connect or coach-chat data, account IDs, email addresses, or subscription and purchase events to the Meta SDK. Automatic content and purchase logging are disabled. Refusing tracking leaves the app usable and does not initialize this measurement SDK. You can withdraw permission in iOS Settings → Privacy & Security → Tracking. Meta processes the received information under its own Privacy Policy; its retention is governed by that policy.

6.1 AI Data Processing Disclosure

Premium weekly digest sent to Google Gemini:

• Week context: week key, week start and end, days covered, covered-through date, and time zone.
• Steps and active energy: each date and weekday with its steps, average, goal, days meeting the goal, low-day dates, weekdays and steps, and average active calories.
• Sleep: average hours, average bedtime minute, and days with data.
• Meals: total and per-day average, snack count, late-night count and days, macro split, average daily calories, evening calorie percentage, and that percentage for each day.
• Calories: calorie goal, each date and weekday with its intake and delta, and average delta.
• Hydration: average millilitres, goal, days meeting the goal, evening share, average minute of first log, and morning share.
• Fasting: started and completed counts, average actual and target hours, and completion rate.
• Weight: start, end, delta, goal, and number of logs.
• Movement by day and totals: movement.byDay[].date, weekday, minutes, neutral outcome, effort, and plannedMinutes; movement.daysMoved; and movement.totalMinutes.
• Movement outcomes and effort distribution: movement.outcomes.completed, partial, skipped, and rest; movement.effortDistribution.reported; and the counts for ratings 1, 2, 3, 4, and 5 in movement.effortDistribution.byRating.
• Movement effort at a comparable dose, when available: movement.effortAtComparableDose.dose.plannedMinutes, level, and volumeStep; previousAvg, currentAvg, delta, previousSamples, currentSamples, direction, and lookbackDays.
• Movement progression: movement.progression.levelStart, levelEnd, and each levelChanges[].date, from, and to; volumeStepStart, volumeStepEnd, and each volumeStepChanges[].date, from, and to.
• Movement/step correlation, when available: movement.correlations.steps.movementDaysAvg, nonMovementDaysAvg, difference, movementSamples, and nonMovementSamples.
• Movement/fasting-hours correlation, when available: movement.correlations.fasting.avgHoursAtMovement, sampleDays, longFastDays, and longFastThresholdHours.
• Movement/sleep correlation, when available: movement.correlations.sleep.beforeAvgHours, afterAvgHours, afterMinusBeforeHours, and sampleDays.
• Meal plan: planned and completed counts and adherence.
• Request context: the derived count of populated data domains (dataDomains), requested output locale, and static system instructions.

Not included in the weekly digest: direct user or account ID, name, email, raw meal entries, raw readiness or body values, reason codes, pain flag, body region, rest reasons, readiness energy, qualification data, or recent insight free text.

Re-identification context: Exact dates, time zone, and locale remain in the request. These can make the otherwise redacted digest more identifying when combined with other information.

Automated decision-making: AI calorie estimation is an automated process. Results are estimates only and not medical advice. You can edit results manually. Turning off the AI-processing setting prevents the Only Fasting mobile client from starting new food-text, food-image, and activity analysis requests.

Premium weekly digest control: The server sends a weekly digest only when the account's AI-processing setting is true. A missing, false, or unreadable setting prevents a new weekly digest from being sent to Google Gemini.

6.2 Cross-Border Data Transfers

Some data is transferred outside the European Economic Area (EEA), including to Google LLC (Gemini API), Anthropic, PBC (Claude API), and, only with iOS tracking permission, Meta Platforms, Inc. (Meta SDK) in the United States. These transfers are subject to the cross-border requirements that apply to the service and user. Operational measures include:

• Data minimization: The weekly digest excludes the fields listed as not included in Section 6.1, but still contains the complete listed digest and exact dates, time zone, and locale.
• Encryption in transit: Requests use HTTPS.

For users in Türkiye, see the KVKK Disclosure Notice and Explicit Consent Text for the stated cross-border processing.

6.3 Momo Coach (AI Chat)

What it is: Momo Coach is an optional chat feature for Premium users aged 18 or older, where available. It starts after the entry consent bundle records your adult declaration and optional AI choice, including Momo Coach; the account's AI-processing setting must be on. Older app versions may use the former separate coach notice. Momo Coach gives general wellness information based on your own records. It is not medical advice.

Sent with each message to the Momo Coach provider processing the message: Momo Coach recipients are Anthropic, PBC (Claude API) and Google LLC (Gemini API), in the United States. For users who accepted the current in-app consent text, Momo Coach's primary provider is, where available, Anthropic, PBC (Claude API), with Google LLC (Gemini API) as the fallback. When the fallback is used, the same message may also be sent to Google LLC (Gemini API). Momo Coach messages from users who accepted an earlier in-app consent text are processed by Google LLC (Gemini API) until they accept the current text. The following data is sent:

• The message you write (up to 300 characters) and, for context, up to the last three questions and answers of the same chat
• A summary of your records for today, each of the last 7 days and a 28-day total: water, meals and logged calories, fasting, weight trend, meal-plan progress and, if connected, supported Apple Health / Health Connect totals such as steps and sleep, and the results of your recent weekly insights
• Your goals and plan settings, your diet-type and allergy selections, the date, your time zone and the app language
• The answer Momo prepares, which passes a second automated safety check before it is shown to you

Not sent: your name, email, profile photo, direct user or account ID, friends, challenges, community posts, or free-text meal names and notes.

Momo Coach record: Unlike the other AI features (Section 8, "AI analysis inputs"), Momo Coach conversations are stored. For every request we keep an encrypted record with your message, Momo's answer or the fixed message shown to you, the record summary sent to the model, the model's raw output, the automated safety decisions, and technical details (model and instruction version, language, app version, platform, time, usage counts and cost). Only authorized personnel can access it, only for the purposes below, and every access is logged.

Purposes: providing the chat and your chat history; checking and improving the quality and safety of answers; preventing misuse and enforcing the usage limits; and establishing, exercising or defending legal claims. We do not sell these records and do not give them to third parties to train AI models. Improvement means internal review and adding de-identified examples to our test sets.

How long: The chat history you see in the app is deleted automatically after 30 days; you can also delete it yourself at any time in the app with "Delete chat history". Deleting the visible history does not delete the Momo Coach record, which remains until the end of its retention period. The encrypted Momo Coach record is kept for 2 years and then deleted automatically; only where it is needed for a specific legal claim or dispute may it be kept until that matter is closed. If you delete your account, the visible chat history is deleted with it, while the Momo Coach record is kept until the end of its 2-year period under a pseudonymous code instead of your account ID. A pseudonymous code is still personal data, and the record stays protected as described here. Usage-limit records (coded digests of your account and store-purchase identifiers, and a receipt per request) are kept for 32 days so that the daily and 30-day limits cannot be bypassed, and are then deleted. Your like/dislike marks on answers are kept for the same period.

Grounds we rely on: your explicit consent for processing the health-related information in the chat and for sending it to Google LLC and Anthropic, PBC in the United States (GDPR Art. 6(1)(a) and 9(2)(a); for Türkiye, KVKK Art. 6 and 9, see the Explicit Consent Text); our legitimate interest in security and preventing misuse (GDPR Art. 6(1)(f); KVKK Art. 5(2)(f)); and, for keeping the record after consent is withdrawn or the account is deleted, the establishment, exercise or defence of legal claims (GDPR Art. 9(2)(f) and 17(3)(e); KVKK Art. 5(2)(e) and 6). Where erasure is limited on this last ground, the record is used only for that purpose.

Your choices: You can stop using Momo Coach and withdraw your Momo Coach consent at any time in the app (you can also write to privacy@onlyfasting.com). After withdrawal no new Momo Coach message is sent to our AI providers listed here; records already created are kept and deleted as described above. Temporary retention, logging and model use on the provider's side are governed by the provider's service settings and the applicable provider terms; this text makes no commitment about them.

7. Data Storage & Security

7.1 Where We Store Data

Your fasting, hydration, nutrition, and movement data is cached locally on your device and synced to an account-linked database hosted by Supabase in the European Union (Frankfurt, Germany). When you use the App without creating an account, the App creates an anonymous guest account tied to your device and syncs your data under that anonymous account. If you later create an account, the same data is linked to it.

7.2 Security Measures

• Network requests use HTTPS
• Authentication and access controls restrict access to account data
• Rate limiting is applied to API requests

8. Data Retention

After account deletion, your personal data is permanently removed within 30 days, except where retention is required by law, the device-level free-use record listed in the table above, and the Momo Coach record and usage-limit records described in Section 6.3. For security, if account session activity is detected after your request, the request will not be processed and you will be notified by email; you can then delete the account from within the App. Data already received by Meta is processed under Meta's own policy and is not deleted by us; you can exercise your rights with Meta and withdraw tracking permission in iOS Settings → Privacy & Security → Tracking.

9. Your Rights (GDPR)

Under the General Data Protection Regulation, you have the following rights:

To exercise any of these rights, contact us at privacy@onlyfasting.com. We will respond within 30 days.

10. California Privacy Rights (CCPA)

If you are a California resident, you have specific rights under the California Consumer Privacy Act (CCPA):

• Right to Know: You can request information about the categories and specific pieces of personal information we have collected about you.
• Right to Delete: You can request deletion of your personal information, subject to certain exceptions.
• Right to Opt-Out: You can opt-out of the sale of your personal information. Note: We do not sell your health, meal, content or account data. Only with your iOS tracking permission, the device advertising identifier and install, app-open and session events are shared with Meta to measure and optimize Only Fasting ad campaigns, as described in Section 6. You can withdraw this permission in iOS Settings → Privacy & Security → Tracking.
• Right to Non-Discrimination: We will not discriminate against you for exercising your CCPA rights.

To exercise these rights, contact us at privacy@onlyfasting.com or use our Delete Account page.

Categories of Information Collected: Identifiers (email, name, device identifiers and, only with iOS tracking permission, the device advertising identifier (IDFA) shared with Meta to measure and optimize Only Fasting ad campaigns), health information, commercial information (subscription status), and internet activity (app usage). The controls and purposes for each category are described above.

Do Not Track: Our App does not respond to "Do Not Track" signals as there is no industry standard for this.

11. Children's Privacy

Only Fasting is not intended for children. You must be at least 13 years old to create an account and use the App. If you are between 13 and the age of digital consent in your country (16 in some EU/EEA member states), you may use the App only with the consent of a parent or legal guardian.

We do not knowingly collect personal data from children under 13. If we become aware that we have collected personal data from a child under 13, we will delete it promptly. If you believe a child has provided us with personal data, contact us at privacy@onlyfasting.com and we will act without undue delay.

Health note: fasting and calorie restriction can be harmful to children and adolescents who are still growing. See the Medical Disclaimer in our Terms of Service.

12. Data Breach Notification

If a personal data breach occurs that is likely to result in a risk to your rights and freedoms, we will notify the competent supervisory authority without undue delay and, where feasible, within 72 hours of becoming aware of it (GDPR Article 33).

Where the breach is likely to result in a high risk to you, we will also notify you directly and without undue delay, describing the nature of the breach, its likely consequences, and the measures we have taken (GDPR Article 34).

For users in Türkiye, we notify the Personal Data Protection Board (KVKK) within 72 hours of becoming aware of a breach and notify affected individuals without undue delay and within the shortest reasonable time, in line with the Board’s breach-notification decision.

13. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of any material changes by:

• Posting the new policy on this page
• Updating the "Last updated" date
• Sending an in-app notification for significant changes

14. Contact Us