USDA FoodData Central
USDA FoodData Central is the United States Department of Agriculture's public food composition database, combining laboratory-analysed foundation foods, legacy reference values and branded product data.
FoodData Central is the most widely used food composition source in the world, largely because it is comprehensive, free and available as bulk data. Most calorie apps outside India are built on it, whether or not they say so.
The data types inside it
Understanding these prevents most confusion. Foundation Foods are newly analysed with full sampling and analytical detail — the highest confidence. SR Legacy is the older Standard Reference set, still the broadest coverage of basic ingredients. Branded Foods comes from manufacturer label data, which means it inherits label tolerances. Survey (FNDDS) values are built for dietary survey work and include many prepared foods.
An app that mixes these without saying which is which can show two very different numbers for what looks like the same item.
Why it is not enough on its own
It describes the American food supply. Its "flatbread" is not a roti, its lentils are not analysed as they are eaten in an Indian kitchen, and its prepared dishes reflect American recipes. Using it for home-cooked Indian food produces numbers that are confidently wrong.
For generic ingredients, packaged goods and anything internationally traded, it is excellent and this site uses it.
Sources
- 1.FoodData Central — USDA Agricultural Research Service
- 2.FAO/INFOODS food composition databases — Food and Agriculture Organization of the United Nations
Related reading
- IFCT or USDA: which numbers should you trust?
Two national food composition tables, built for two food supplies. When each one is right, why they disagree about the same food, and what to do about it.
- Why two apps give the same roti different calories
Different databases, source types, raw versus cooked states and user-submitted entries. Why calorie apps disagree, and which number you should actually use.
- How to judge a calorie app's food database
Six checks that take ten minutes and tell you more than any review. Where entries come from, why duplicates matter, and what a good result looks like.
- How to calculate the calories in a recipe you cooked
A worked example from a real pot of dal: count the raw ingredients, add the fat, divide by real servings, save the number. Fifteen minutes once per recipe.