USDA FoodData Central
USDA FoodData Central is the U.S. Department of Agriculture's official, publicly available database of nutritional composition values for foods. It is the authoritative reference for calorie and macronutrient content of whole foods in the United States, and it serves as the ground-truth database for Calorie Tracker Lab's accuracy testing protocol.
What is USDA FoodData Central?
USDA FoodData Central (FDC) is the U.S. Department of Agriculture’s authoritative database of food composition values. Maintained by the Beltsville Human Nutrition Research Center, it consolidates several previously-separate USDA databases into a single queryable system, accessible at fdc.nal.usda.gov. It is free to access, with a documented API and bulk-download options for researchers.
FDC is organized into several sub-datasets, each with different provenance and intended use:
- SR Legacy. The historical USDA Standard Reference dataset (final release: SR28, 2018). Comprehensive coverage of whole foods; foundational reference for U.S. food composition work.
- Foundation Foods. Extension of SR Legacy with newly analyzed foods, sampled and analyzed under a published protocol. Replaces SR Legacy entries as new analyses are completed.
- FNDDS (Food and Nutrient Database for Dietary Studies). The dataset used to translate “what people eat” into nutrient values for the National Health and Nutrition Examination Survey (NHANES). Includes mixed dishes and recipes.
- Branded Foods. Manufacturer-submitted data for branded packaged products. Lower verification rigor than the analysis-based datasets but broader coverage of grocery-store SKUs.
- Experimental Foods. Newer entries for non-traditional or research-only foods.
How is it used in our testing?
USDA FoodData Central is the ground-truth database for Calorie Tracker Lab’s accuracy battery. Every weighed reference meal in our test battery is built from FDC entries: each ingredient’s calorie and macro values come from FDC’s SR Legacy or Foundation Foods entries (for whole foods) or from FDC’s Branded Foods data verified against the manufacturer’s label (for packaged items). The whole meal’s ground-truth calorie value is the sum of FDC values scaled by the calibrated weighed portions.
We chose FDC as the reference database for three reasons. First, it is the authoritative reference used by U.S. clinical and research dietary-assessment work; aligning with it lets our consumer-app testing be cross-referenced against the published academic literature. Second, it is publicly available — every claim we make about a meal’s true calorie content can be independently verified by a reader. Third, FDC is updated continuously, so reference values reflect current food-composition science.
Why it matters in calorie tracking apps
For users comparing calorie tracking apps, the underlying database an app uses matters enormously. Apps that source from USDA FDC for whole foods, or that maintain a curated verified food database of comparable rigor, produce more reliable manual-entry calorie counts than apps that rely heavily on user-submitted entries (see crowdsourced database for the failure modes). The lab’s database-quality criterion (20% of the 100-point rubric) is built around how an app’s database compares to USDA FDC for canonical entries and how the app handles regional foods, restaurant items, and branded products.
For methodologists, FDC is the lingua franca of U.S. dietary-assessment research. Our methodology is designed to be readable in that context — every calorie value we publish for a reference meal can be traced to a specific FDC entry and a specific calibrated weighing.