Methodology

NutritionRef processes data from two USDA FoodData Central datasets:

Data sources

• SR Legacy (2018-04) — the USDA Standard Reference database, containing ~8,000 commonly consumed foods with comprehensive nutrient profiles.
• Foundation Foods (2025-12-18) — higher-quality analytically measured data for selected foods, with stricter protocols and multiple samples.

Processing pipeline

1. Filter — Only sr_legacy_food and foundation_food data types are retained. Branded, survey, and experimental entries are excluded.
2. Deduplicate — When a food appears in both SR Legacy and Foundation, the Foundation entry is preferred (higher analytical quality). Foods with identical names are merged.
3. Quality floor — Foods with fewer than 5 cataloged nutrients are excluded.

Nutrient values

All values are reported per 100g of the edible portion, as stored in the USDA database. No values are modified or interpolated.

Missing values are displayed as — and never substituted with zero.

Reference daily intakes

RDA/AI values shown are for an adult male aged 19–50, sourced from the NIH Office of Dietary Supplements and USDA DRI tables. These are informational only — see the disclaimer.