Data & method

The dataset

Every figure comes from USDA FoodData Central, SR Legacy release — the long-standing Standard Reference database maintained by the US Department of Agriculture's Agricultural Research Service. As a work of the United States government it is in the public domain.

Citation: U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, SR Legacy release. Public domain. Downloaded from fdc.nal.usda.gov on 2026-07-28.

Which foods are published

SR Legacy contains 7,793 entries, a great many of which are laboratory-specific variants ("beef, chuck, arm pot roast, separable lean only, trimmed to 0" fat, all grades, cooked, braised"). Publishing all of them would produce thousands of near-identical pages that help nobody.

Instead 1799 foods are published, chosen by scoring each entry for how likely a person is to actually look it up — simpler descriptions score higher, industrial and brand-specific entries score lower — with a per-category quota so that coverage stays broad, plus a guaranteed-inclusion list of everyday staples. Entries without an energy value are excluded, as are baby foods. The full USDA description and FDC ID are printed on every page so you can verify any figure at source.

Servings and portions

Per-100 g values are what the USDA measures. Household measures (a cup, a slice, a medium one) come from the USDA's own portion table, and per-serving figures are a straight proportional conversion — nothing is rounded up or "adjusted".

The macro split

Percentages use the Atwater factors: 4 kcal per gram of protein and carbohydrate, 9 per gram of fat. These are approximations, and they will not always reconstruct the stated calorie figure exactly, because the USDA derives energy values by several methods depending on the food.

The "walk it off" figure

Calculated as MET 4.0 walking for a 70 kg adult, using the equation on our sister site BurnLab. It is there to give a sense of scale. It is not a prescription, and the idea that a food can be neatly "cancelled" by exercise is not how appetite or metabolism actually behave.

What reference values cannot tell you

• Real food varies. Variety, ripeness, soil, season, cut, brand and cooking method all move these numbers, commonly by 10–20%.
• "Raw" and "cooked" are different foods. Cooking removes water, which concentrates everything per gram. Check which entry you are reading.
• A missing value is not a zero. A dash means the nutrient was not measured for that item.
• SR Legacy is a historic release. It is stable and citable — which is exactly why it is used here — but it is no longer being expanded with new items.

General information only — not medical or nutrition advice. Values are averages for a food type and vary by brand, ripeness and preparation.

Corrections

If a figure here disagrees with FoodData Central, FoodData Central is right and this site is wrong. Send the page URL and it gets fixed.