Privacy Policy

Last updated: March 2026

1. Data Controller

Markus Köplin
Fehmarner Str. 1, 04159 Leipzig, Germany
Email: support@mkhub.de

2. What Data Is Processed?

• Nutrition data: Meals, calories, macronutrients (protein, carbohydrates, fat), water intake
• Body data: Weight, body fat, body measurements, height, age, gender
• Profile data: Display name, goals, settings, allergy choices, and optional profile picture
• Activity data: Steps, active calories, workouts (via Apple Health)
• Sleep data: Optional sleep duration and simple sleep-context insights from Apple Health
• Usage data: Subscription status, pseudonymous installation identifier, active usage days, coarse feature/AI usage counters, technical error and latency classes, pseudonymous device identifier for the Friends feature

3. Storage Location

Your nutrition, body, activity, profile, and settings data is stored locally on your device. Optionally, it is synced across your devices via iCloud. Profile pictures are stored only as compressed avatar images, not as original photos.

AI coach chats are stored locally on the device for short-term continuation and are automatically limited. Your food diary is not stored as a central user account on our own server. However, optional online features and technical product operations process the requests required for those purposes: AI requests, pseudonymous usage statistics, App Attest verification, and support traceability run through a Cloudflare Worker proxy, online food search may use the NährWert API and external food data services, and the Friends feature uses a Friends server.

4. AI Processing (Plus/Pro)

When you use AI features (chat, photo analysis, text input), the entered text or photos are transmitted via an encrypted proxy service to OpenAI as the technical service provider.

• Transmission is encrypted.
• No account data such as name, email, or Apple ID is automatically transmitted. However, the content of your request may contain personal data if you enter or upload such information yourself.
• To protect against misuse, provide the service, control costs, understand product usage, and support users, a pseudonymous random installation identifier may be processed. It is not IDFA, not cross-app tracking, and cannot be directly attributed to you.
• Continuable AI coach chats store only role, text, timestamp, and technical response pointers locally. Images, Base64 data, and nutrition-context snapshots are not stored in the chat history.
• For chat continuation, the app uses OpenAI Responses with stored application state. These responses may be retrieved for a limited time to continue context and for defensive recovery.

Your inputs for AI features are processed by our technical AI service provider OpenAI. Based on our current technical and contractual setup, the transmitted content is not used to improve or train general models. The applicable contractual and technical settings of the service provider apply.

AI recommendations are generated automatically but are not the basis of automated individual decisions within the meaning of Art. 22 GDPR. They serve solely as non-binding guidance.

5. Food Search

When searching for food items online, search terms, barcodes, language/country settings, and technical request information may be processed through the NährWert API and forwarded to external food data services such as Open Food Facts. Depending on the lookup, requests may also be sent directly from the device to external services. Your IP address is processed for technical reasons. Open Food Facts processes data in accordance with its own privacy policy.

The NährWert API may contain the requested product code and request time in technical server logs. Internal product-code aggregates may be derived from them to improve the quality and coverage of our product database. IP address, full request URL, user agent, and installation identifier are discarded; only product code, request count, and first and last observed request are evaluated. These data are not used to create nutrition, health, advertising, or user profiles.

6. Apple Health

The app reads and writes health data via Apple Health. Access only occurs with your explicit permission and can be revoked at any time in the iOS or Health settings. Sleep data is optional, evaluated locally only for careful nutrition prompts, and is not sent to AI or external services. Apple Health data is not transmitted to external third parties by the app. Synchronization via Apple services you have activated, particularly iCloud, remains unaffected.

6a. Siri, Spotlight, and Shortcuts

NährWert provides local App Intents for Siri, Spotlight, and the Shortcuts app. They allow faster logging or querying of water, weight, and daily values. These intents access locally stored SwiftData in the App Group store and do not send nutrition or health data to our own servers. Write actions and sensitive queries require device authentication and use Apple's system dialogs. Apple Health is not written without an existing permission.

6b. Friends

When you use the Friends feature, the Friends server processes your friend code, display name, streak, and tracked days. A pseudonymous device identifier is processed to technically associate your device with your friend code. It is based, where available, on the iOS Identifier for Vendor or on a random UUID, is not IDFA, is not used for cross-app tracking, and is used only to provide the Friends feature. After a friendship is accepted, your streak and tracked days are visible to your friends. Your personal goal type, for example losing or gaining weight, is not visibly shared with friends. Optionally, you can also share your macro progress as percentage values for carbohydrates, protein, and fat; gram values, calories, and meals remain private. Friend data is stored locally in the app and can be removed by removing the friendship or by using “Delete Local App Data”.

6c. Pseudonymous Usage Statistics and Support

NährWert processes a random app-specific installation identifier as a support and analytics ID. We use it to measure active installations, rolling active users over 3, 6, and 9 days, coarse feature usage, AI adoption, technical error classes, latency, and cost/capacity indicators. The same identifier is also used in Worker, Cloudflare AI Gateway, and OpenAI metadata so support cases and AI costs can be traced per installation.

Pseudonymous analytics events do not contain meal names, calories, macros, water, weight or body values, Apple Health values, photos, barcodes, search terms, AI prompts, chat text, names, email addresses, Apple ID, StoreKit transaction data, or friend codes. The technically necessary processing of product codes for online food search is described in section 5. This processing is not used for advertising, data broker purposes, cross-app tracking, or third-party profiling.

You may optionally consent to sending valid product codes that remain missing after the complete product-database lookup. Confirmed missing and partially checked codes are aggregated separately with the report day, coarse app/system locale, and app version. They are not linked to installation, IP, device, subscription, AI, support, or advertising identifiers. This transfer remains off without explicit consent; found, invalid, cancelled, or technically failed lookups never send a product code. Aggregates are retained for no more than 400 days.

7. Recipients and Third-Country Transfers

We only share personal data to the extent necessary for the described features.

Apple / iCloud

Purpose: Optional synchronization of your app data via iCloud
Legal basis: Art. 6(1)(a) or (b) GDPR, depending on usage
Country / third-country aspect: Processing may occur across borders; Apple's privacy terms apply

OpenAI

Purpose: Processing your inputs when using AI features and continuable chat context
Legal basis: Art. 6(1)(a) GDPR; for health data additionally Art. 9(2)(a) GDPR
Country / third-country aspect: USA; safeguarded via the EU-US Data Privacy Framework adequacy decision and/or Standard Contractual Clauses

Cloudflare

Purpose: AI proxy, food proxy, Friends backend, App Attest verification, rate limiting, pseudonymous product analytics, and support traceability
Legal basis: Art. 6(1)(b) GDPR or Art. 6(1)(f) GDPR
Country / third-country aspect: USA; safeguarded via the EU-US Data Privacy Framework adequacy decision and/or Standard Contractual Clauses

Open Food Facts

Purpose: Online food search and retrieval of product information
Legal basis: Art. 6(1)(b) GDPR or usage at your explicit request
Country / third-country aspect: Depends on the technical provision of the service

NährWert API

Purpose: Technical provision and protection of online food search
Legal basis: Art. 6(1)(b) GDPR or Art. 6(1)(f) GDPR
Country / third-country aspect: Depends on hosting and technical provision

8. Storage Duration

Your data is stored as long as you use the app. You can delete local app data at any time within the app (Settings → Privacy & Data → Delete Local App Data). This also includes profile data and an optional profile picture. Local AI coach chats are limited to 14 days and a maximum of 100 messages per active session and are removed locally by “Delete Chat” or “Delete Local App Data”. When the app is uninstalled, local data is generally removed by the operating system. Apple Health data and iCloud data can additionally be deleted through their respective system settings. AI content already transmitted to OpenAI is subject to OpenAI's application-state and privacy rules.

Pseudonymous raw analytics events are generally stored for up to 90 days for support and rolling metrics; aggregated daily metrics may be stored for up to 400 days. Technical log or abuse prevention data related to AI features and online food search is only stored for as long as necessary for secure provision, error prevention, and product-database maintenance.

9. Your Rights

You have the right to access, rectification, erasure, restriction of processing, data portability, and objection.

Right of withdrawal: You may withdraw any consent given at any time with effect for the future.

• AI features: You can withdraw consent within the app or by email to support@mkhub.de.
• Apple Health: You can additionally revoke access at any time in your device's Health or iOS settings.

The lawfulness of processing carried out prior to withdrawal remains unaffected.

For local data, you can start deletion directly in the app: Settings → Privacy & Data → Delete Local App Data.

10. Right to Lodge a Complaint

You have the right to lodge a complaint with a data protection supervisory authority. The competent authority is:

11. Changes

This privacy policy may be updated with app updates or changes to data processing. The current version is always available in the app under Settings → Privacy & Data → Privacy Policy and at naehrwert-app.de/en/privacy.