Volume I · Founded 18 November 2025 · Edited by James Oliver
The editorial reference for measurement accuracy in nutrition.
A working glossary of the terms that actually determine whether a calorie figure is credible: USDA FoodData Central releases, FDA label regulation, kitchen-scale precision, laboratory reference meals, and the statistical measures — MAE, MAPE, RMSE — that a serious publication uses instead of adjectives.
House rules
Numbers, not adjectives
"Accurate" is not a claim. Every accuracy assertion on this site carries an error figure (MAE, MAPE, or RMSE), a reference meal set, and the sample size that produced it.
Primary sources only
Entries cite the USDA FoodData Central release, the FDA regulation, the peer-reviewed paper. No blog-post authority, no re-reported figures.
Named alongside, not named alone
When a consumer app is mentioned, it's mentioned in a field of at least three, with each app's accuracy number attached. No endorsements.
Recently filed
View the full index →- Dietary Assessment Mean Absolute Percentage Error (MAPE) The average of the absolute percentage differences between estimates and reference values — the accuracy measure most often quoted for consumer calori…
- Dietary Assessment Inter-App Variance The spread of calorie and nutrient estimates produced by different tracking apps for the same food or meal — a practical consequence of differing unde…
- Dietary Assessment Per-Meal Error Band The expected range of estimation error for a single meal logged by a given method — the practical accuracy figure that matters for per-meal decisions,…
- Dietary Assessment Portion-Size Error The contribution to total estimation error that arises from inaccurate determination of the amount of food consumed — often the dominant error source …
- Dietary Assessment Mixed Dish Error The elevated estimation error specific to composite meals — casseroles, stews, stir-fries, curries, salads — whose ingredient composition cannot be fu…
- Dietary Assessment Top-1 vs Top-5 Accuracy The convention for reporting classification performance at the strictest threshold (top-1, the single best prediction) and a more permissive threshold…
Editor's note
"I spent a decade reading food-policy copy that treated a calorie number as though it had been handed down from the manufacturer's lawyer rather than measured. The truth is shabbier and more interesting. A credible calorie figure is the end of a chain — Atwater factors, laboratory calorimetry, a specific USDA release, a regulated rounding rule, a kitchen scale with a tolerance printed on the box, a photo-logging model with a validated MAPE. This publication covers that chain, one term at a time."
— James Oliver, Editor