fat-os

fat-os takes a meal plan out of a PDF or a WhatsApp chat and turns it into an app you follow in a few seconds, several times a day. Whoever writes the plan, a nutritionist or a coach, gets an area of their own to follow along.

On the phone, you see today’s menu, swap a meal for one of its substitutes and tap “Comi” (“Ate it”). You also log water, tick off supplements and keep a pantry that becomes a shopping list when something runs out. Each day counts as a match in a ranked ladder, from Iron to Challenger, which gives you a reason to come back tomorrow. The app installs on the home screen, and on a computer the navigation moves to a sidebar.

Tapping “Comi” takes the meal’s ingredients out of the pantry, converting grams and kilos, milliliters and liters, and ignoring accents and plurals, so “Ovos” and “ovo” are the same item.

The technical decision I like most is keeping one source of rules for the data. The app runs on its own server, on Supabase, or with Postgres inside the browser, and all three modes use the same SQL and the same row-level security. Each person can only read and write their own data, and the database enforces it, not the interface.

To try it without signing up, the login screen offers a test account with a menu, a pantry and three weeks of history. It resets every day.