Consumer test · 60 seconds
The five-scan test: is your calorie app measuring, or guessing?
You can't verify a calorie number against the "truth" without a lab. But you can verify something almost as useful in one minute: whether your app gives the same answer to the same question. An instrument that returns different readings for identical input isn't measuring anything.
The test
- Plate one meal. Don't touch it again.
- Scan it five times, same angle, seconds apart — in whatever calorie app you use.
- Write down the five totals.
- Open any result and look for the source of each number. Is one shown?
Reading the result: one number five times means the app resolves food against a fixed database — it's auditable. Three or four different numbers means a model is improvising each time; averaging guesses isn't accuracy. And a number with no source can't be checked by anyone, including the company that made it.
Why Proba passes by construction
Proba's AI only identifies foods and grams; the numbers come from USDA FoodData Central and are reconciled against their own macros before you see them. Same photo → same foods → same USDA rows → same answer. Every receipt line cites its source — the full method, including its honest limitations, is on the methodology page.
Run the test on Proba too. If a scan ever disagrees with itself, the receipt will show you exactly which line changed and why — that's the point of receipts.
Run it on Proba — free, 3 scans/day