Weighed Reference Meals
Meals whose ingredient masses are measured on a calibrated kitchen scale, with calorie content computed from USDA FoodData Central composition values, used as ground truth for app accuracy testing.
A weighed reference meal is a meal whose every ingredient mass has been measured on a calibrated kitchen scale (precision 0.1g), with the calorie content computed from USDA FoodData Central composition values. The computed total is treated as the ground truth against which a calorie tracking app’s prediction is compared.
Why we use weighed reference meals
The clinical gold standard for energy intake assessment is doubly labeled water (DLW), which measures total energy expenditure over 1-2 weeks. DLW is not feasible at scale for app testing. The next-best option, used in academic dietary-assessment validation studies (Subar 2015; Boushey 2017), is weighed records — every food item is measured to the gram before consumption.
For consumer-app benchmarking, weighed reference meals isolate one variable: how accurately the app translates a known food → kcal. They do not measure how accurately the app would handle a free-living user who eyeballs portion sizes — that’s a separate test we report under “real-use friction.”
How we build them
Our reference battery is stratified across three tiers: single ingredients (banana, chicken breast, egg), composed plates (chicken-and-rice bowl, oatmeal with toppings), and mixed dishes (lasagna, curry). The full battery and per-item composition will be published as a downloadable CSV.