Methodology
The AI never invents a number. Here's the whole method.
Most photo calorie apps ask an AI model to output calories directly. Models are good at recognizing food and bad at arithmetic recall — which is why the same plate can return three different numbers. Proba splits the job:
- The model identifies, it doesn't count. The vision model's only output is a list of foods and estimated gram weights — {food, grams}, nothing else.
- The database does the counting. Each food resolves against USDA FoodData Central — public-domain, lab-analyzed data. Calories and macros come from the matched USDA entry, scaled by grams. Packaged foods use the barcode label directly.
- A reconciliation gate rejects nonsense. Every result is checked against the Atwater relation (4·protein + 4·carbs + 9·fat). If the calories deviate more than 20% from what the macros imply, the macros win. Physically impossible database rows (over 900 kcal per 100 g, macro sums over 105 g/100 g) are rejected.
- You see the receipt. Pull down any result: every line shows its grams and its USDA source. If a food couldn't be grounded, the receipt says so — it never fabricates a citation.
- Determinism. Same photo → same foods → same USDA rows → same answer. Run our five-scan test on any app, including this one.
What the glucose line is (and isn't)
Each receipt carries an estimated glucose-impact band computed from meal composition (glycemic load from carbs, fiber, fat, protein). It is labeled in-app exactly as what it is: an estimate from meal composition — not a CGM measurement. If you wear an over-the-counter CGM, Proba can read your Apple Health glucose data to pair meals with your real curves.
Honest limitations
- Portion size is the dominant error for every photo app, ours included: a single 2-D photo can miss volume by ±30–50%. That's why grams are editable before saving — and why the app learns your typical portions over time.
- Hidden fats: a tablespoon of cooking oil (~120 kcal) can be invisible in a photo. Fried and sautéed dishes carry an oil assumption you can correct.
- Mixed dishes: stews and layered plates ground less precisely than separable items; confidence is shown, and low-confidence results ask instead of asserting.
Accuracy claims worth trusting are testable. Ours are: the citations are on every receipt, and the repeatability test takes five scans of one meal.
Get Proba on the App Store