USDA FoodData Central

FoodData Central (FDC) is the U.S. Department of Agriculture's integrated food-composition database, maintained by the Agricultural Research Service and launched in April 2019 to replace the National Nutrient Database for Standard Reference. It is, in practice, the ledger the American nutrition infrastructure runs on — the underlying source for most Nutrition Facts label calculations, most clinical dietary-assessment instruments, and most consumer tracking apps, whether they cite it directly or not.

What sits underneath the portal

FDC is not a single database. It is a portal that exposes five distinct source datasets, each with its own collection protocol and use case:

• SR Legacy — the frozen final release of Standard Reference, April 2018, preserved as the historical backbone.
• Foundation Foods — a small, slowly-growing set of high-quality analyses with full sampling and uncertainty documentation.
• FNDDS (Food and Nutrient Database for Dietary Studies) — the USDA's dietary-recall reference, tied to What We Eat in America and NHANES.
• Branded Foods — manufacturer-submitted label data covering roughly 1.5 million consumer items.
• Experimental Foods — pre-publication research data, used cautiously.

The distinction matters. A 'calorie per gram' figure pulled from Foundation Foods carries an uncertainty estimate and a sample size. The same figure pulled from Branded Foods is whatever the manufacturer entered to satisfy labelling, within FDA tolerances. They are not equivalent and should not be cited interchangeably.

The FDC ID

Every entry in FoodData Central carries a numerical FDC ID, which persists across API versions. For reproducibility in dietary-assessment research, citing an FDC ID is meaningfully better than citing a food name — 'Greek yogurt, plain, nonfat' returns dozens of entries; FDC ID 170894 returns one. Publication-grade nutrition research in the American Journal of Clinical Nutrition and the Journal of Nutrition increasingly requires FDC IDs in supplementary materials.

What downstream tools actually do with it

Consumer tracking apps handle FDC in one of three ways. A small number license FDC directly and expose the FDC ID to the user. A larger number ingest FDC through commercial aggregators (Nutritionix, Edamam, Open Food Facts), adding their own community entries alongside. A handful operate proprietary databases entirely. The difference is visible in entry metadata when the app exposes it — an entry tagged 'USDA Foundation' is a different epistemic object from one tagged 'User-submitted'.

Known limitations

FDC is not complete. Branded Foods coverage is dense but shallow, heavily skewed toward U.S. shelf-stable products. Restaurant and foodservice items are absent. International items are patchy. Prepared dishes are represented via FNDDS recipe recipes rather than direct analysis. Most importantly, nutrient coverage is uneven — a given entry may have kilocalorie and macronutrient figures but be missing choline, iodine, or selenium. Researchers working outside the core macronutrients should check the nutrient coverage of every entry they cite.