Nutrition Encyclopedia pairs a structured nutrition database with editorial review. This page explains how our data is gathered, verified and maintained.
Where our data comes from
Core nutrition figures for each food — energy, macronutrients, vitamins and minerals — come from USDA FoodData Central, expressed per 100 g so foods are directly comparable.
Compound and anti-nutrient values come from a wider set of sources, because no single database covers them. Purine figures are from the USDA/ODS-NIH Database for the Purine Content of Foods (Release 2.0, 2025). Oxalate figures for nuts and seeds are from the Harvard oxalate table (2023), using directly-measured values only. Others come from individual peer-reviewed papers, cited on the compound page itself.
How data enters the site
Data is ingested through a controlled pipeline that writes to a dedicated, validated database via an authenticated API, rather than typed in ad hoc. Every food, compound and biomarker is stored as a structured, slug-addressable record, and each food–compound figure records where its value came from. Some of those values are still working approximations rather than measurements from a named source; where that is the case, the ranking page says so.
Citations
Where a compound has supporting clinical research, the relevant studies are linked at the foot of the page with their journal, year and a link to the original paper (PubMed or DOI). We encourage readers to consult the primary source.
Review & corrections
Values are approximations and are reviewed periodically for accuracy. If you spot an error, please contact us and we will investigate and correct it.