Privacy Policy
Effective September 5, 2026
Waistline is a personal AI weight loss coach made by Waistline ("we", "us"). This policy explains what information the app and this website handle, where it goes, and what never leaves your phone. The short version: your logs live on your device, your conversations are processed by AI providers to generate replies, and we do not sell anything about you to anyone.
What stays on your phone
Your meal logs, weight entries, workouts, progress photos, streaks, and the coach's memory notes are stored in a database on your device. We do not run accounts or cloud sync today, and we cannot see this data. If you delete the app, that data is deleted with it.
What is sent to servers, and why
When you talk to your coach, log food by photo or description, or view an AI generated summary, the app sends the relevant content to our server, which forwards it to an AI model provider to generate the response. That content can include your messages, meal photos you submit for calorie estimates, and a summary of your recent logs and profile numbers, since the coach needs them to give grounded advice.
Our server forwards this content and returns the reply. We do not store your conversations or photos on our server. AI processing is provided by OpenRouter and the model providers it routes to, under their own privacy terms. We send only what is needed to produce the reply, and it is never used by us for advertising.
What we collect on this website
The waistline.ai website does not use analytics trackers or ad cookies. Standard web server logs (IP address, request time, page requested) are kept briefly for security and debugging.
Beta distribution
The app is currently distributed through Apple TestFlight and direct Android installs. Apple provides us basic beta information such as your email invitation status and crash reports, handled under Apple's own privacy terms.
What we never do
We do not sell your personal information. We do not share it with data brokers or advertisers. We do not use your conversations, logs, or photos to train models.
Health disclaimer
Waistline provides general wellness information and AI generated estimates. It is not a medical device and does not provide medical advice, diagnosis, or treatment. Calorie and nutrition figures are estimates. Talk to a doctor before starting any weight loss program, and do not use Waistline if you have or are recovering from an eating disorder.
Children
Waistline is not directed at children and is intended for users 18 and older. We do not knowingly collect information from anyone under 13.
Your choices
You can delete individual logs, coach memories, or chat history inside the app, and deleting the app removes all locally stored data. For any privacy question or request, email us and we will help.
Changes
If this policy changes in a meaningful way, we will update this page and the effective date above.