MyFitnessPal

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Do not build this. A food database that has everything is the product, and it is decades of accumulated entries.

Every packaged product in every country, every restaurant item, every barcode. Much of it is user-submitted and some of it is wrong — which is a real criticism — but the coverage is the reason it gets used, and coverage is exactly what you cannot bootstrap.

WHAT TO DO INSTEAD
- Keep it if you need barcode coverage for supermarket food
- If you eat mostly the same things and cook, that is a much smaller problem and the version below is better for it

WHAT YOU CAN BUILD, AND SHOULD

STACK
- A PWA that works offline, SQLite on device, an optional sync server storing ciphertext

WHAT TO IMPLEMENT
- Seed from an open food composition database — several national ones publish laboratory-derived values freely — with the edition recorded so a figure can be traced
- An open product database for barcodes, honestly labelled as patchier than a commercial one. A missing barcode means typing it once
- **Your own foods are the point.** Most people eat perhaps sixty things. Log one in three seconds: search, portion, done, with recent and frequent first
- Saved meals that log six items at once, which is where the speed actually comes from
- Recipes: ingredients in, nutrition per serving computed, stored as a food
- Targets with a source cited, and never a number presented as medical advice
- Write to the platform's health store and read back what other applications recorded

THE HONEST WARNINGS
- Nutrition figures vary by cultivar, brand, portion and cooking. Any tracker's numbers carry a wide margin, and displaying two decimal places is lying about precision. Round generously
- Calorie tracking is a useful tool for some people and genuinely harmful for others. Build no streaks that punish a missed day, no shaming, and a way to hide the numbers entirely. If you would not say it out loud to somebody, do not put it in a notification

THE ONE-LINE VERSION
Nobody can rebuild the barcode coverage. Build the sixty foods you actually eat, and be careful with the tone.