Privacy Policy

Deficit — Calorie & Macro Tracker Last updated: March 9, 2026

Overview

Deficit is a calorie and nutrition tracking app that stores your data locally on your device. We do not require account creation, we do not sell or share your personal data with advertisers, and we do not use your data for tracking across other apps or websites.

This Privacy Policy explains what information we collect, how we use it, and your rights regarding that information.

What Data We Collect

Data You Provide

• Food and nutrition data — food items, quantities, and nutritional values you log
• Profile information — gender, weight, height, body fat percentage, and activity level used to calculate your calorie and protein goals
• Photos — images taken through the app for AI-powered food detection, sent to our server for processing and not permanently stored
• Voice input — voice recordings used for food detection, processed via on-device speech recognition (Apple Speech Recognition); audio never leaves your device — only the resulting transcribed text is sent to our server for food identification

Data from Apple Health (HealthKit)

With your permission, the app reads the following data from Apple Health:

• Weight measurements
• Body fat percentage
• Step count
• Workout data (type, duration, calories burned)
• Biological sex

We only read data from Apple Health. We do not write to it. Health data stays on your device and is never sent to our servers or shared with third parties.

Data Collected Automatically

We use PostHog, a privacy-focused analytics service, to collect anonymous usage data including:

• Features accessed and interaction patterns
• App performance metrics and crash reports
• Device type and operating system version

This data is not linked to your identity and cannot be used to identify you. It is used solely to improve the app experience. PostHog’s privacy policy: https://posthog.com/privacy

How We Use Your Data

Food Detection (AI-Powered)

When you use the camera or voice input to identify food, your data is processed as follows:

1. Photos: Your food photo is sent from your device to our server, which forwards it to the Anthropic API (Claude) and/or OpenAI API for food identification and nutrition estimation. Photos are processed in real-time and are not permanently stored on our servers or by our AI providers. We use API configurations that do not permit the use of your data for model training.
2. Voice input: Audio is processed entirely on your device using Apple Speech Recognition. Only the resulting text transcription is sent to our server, which forwards it to the Anthropic API and/or OpenAI API for food identification. Audio recordings never leave your device.

Important: Before using AI-powered food detection for the first time, the app will ask for your explicit consent to send data to these third-party AI services.

Food Search

Search queries are sent to the FatSecret API to look up nutritional information from their database of over 80 million foods. Only the search query text is transmitted — no personal information is included in these requests.

Some nutritional data displayed in the app may also be sourced from Open Food Facts, an open database available under the Open Database License (ODbL), and from USDA FoodData Central, a public domain resource.

Calorie and Nutrition Calculations

Your profile data (weight, body fat, activity level) is used locally on your device to calculate personalized calorie and protein goals using standard nutritional formulas. This data is never sent to our servers.

Analytics

Anonymous usage data helps us understand how the app is used, identify bugs, and prioritize improvements. This data cannot be linked back to you individually.

How We Store Your Data

All personal data — food logs, profile information, goals, and health metrics — is stored locally on your device using encrypted local storage. There are no user accounts, no cloud sync, and no server-side database of your personal data.

If you delete the app, all locally stored data is permanently removed.

Third-Party Services

We do not sell, trade, or share your personal data with any third parties for advertising or marketing purposes.

Apple Health (HealthKit)

In accordance with Apple’s requirements:

• Health data read from Apple Health is used solely for displaying your health metrics and calculating personalized nutrition goals within the app.
• Health data is never sent to our servers, shared with third parties, or used for advertising.
• Health data is not stored in iCloud or any cloud service.
• You can revoke Health access at any time in iOS Settings > Privacy & Security > Health.

Data Retention

Because Deficit stores data locally on your device, your data persists until you choose to delete it or uninstall the app.

For data that passes through our server transiently (food photos for AI detection, search queries):

• Food photos and text: Processed in real-time and discarded immediately after a response is generated. Not stored on our servers.
• Search queries: Transmitted to FatSecret’s API in real-time. We do not log or store search queries on our servers.
• Analytics data: Retained by PostHog in anonymized form in accordance with their data retention policies. This data is not linked to your identity.

Your Rights

You have the right to:

• Access your data — all your data is stored locally on your device and visible within the app
• Delete your data — uninstalling the app removes all locally stored data. You may also delete individual food logs, meals, or profile data within the app.
• Revoke permissions — disable Health, camera, or microphone access at any time in iOS Settings
• Opt out of analytics — contact us and we will disable analytics data collection for your device
• Withdraw AI consent — you can stop using AI-powered food detection features at any time; no data will be sent to third-party AI services unless you actively use these features

For European Economic Area Residents

If you are located in the European Economic Area, you also have the right to data portability, restriction of processing, and to lodge a complaint with your local data protection authority. Our legal basis for processing data is your consent (which you provide when granting permissions and using features that send data to our servers) and our legitimate interest in providing and improving the app.

For California Residents

If you are a California resident, you have rights under the California Consumer Privacy Act (CCPA) including the right to know what data is collected, to request deletion, and to opt out of the sale of personal information. We do not sell personal information.

Children’s Privacy

Deficit is not intended for use by anyone under the age of 18. We do not knowingly collect data from children or minors. If you believe someone under 18 has used the app, please contact us and we will take appropriate steps.

Health Disclaimer

Deficit is not a medical device and does not provide medical advice, diagnosis, or treatment. Calorie, protein, and nutrition calculations are estimates based on standard formulas (including the Cunningham equation for BMR) and should not be interpreted as a substitute for professional medical consultation. Nutritional data sourced from third-party databases (FatSecret, Open Food Facts, USDA) may contain inaccuracies. Always consult a qualified healthcare provider before making significant changes to your diet, especially if you have a medical condition or eating disorder.

Changes to This Policy

We may update this policy from time to time. Material changes will be communicated through the app or on the page where this policy is hosted. The “Last updated” date at the top reflects the most recent revision. Your continued use of the app after changes are posted constitutes acceptance of the updated policy.

Contact

If you have questions about this Privacy Policy or your data, contact us at:

privacy@deficitapp.io