Guides
15 guides on reading and using USDA nutrition data.
A Beginner's Guide to Macronutrients vs. MicronutrientsOne group is measured in grams and fuels every move you make; the other is measured in milligrams and keeps the machinery from breaking down — here's how to actually use both.By Phuoc Huynh
Complete vs. Incomplete Proteins: What the Data Actually ShowsTwo proteins can post nearly identical lysine numbers and still land in opposite categories — the real split comes down to a handful of amino acids counted in milligrams, not grams.By Phuoc Huynh
Foundation Foods vs. Branded Foods vs. Survey Data: What's the Difference?This site's food record types aren't interchangeable — and one of USDA's major data types isn't in this database at all yet. Here's what Foundation, Survey (FNDDS) and Branded actually mean, and what's really behind a number you look up here.By Phuoc Huynh
How Cooking Method Changes Nutrient Values (and Why Raw ≠ Cooked)USDA's own measured data shows cooking can cut some nutrients by half while leaving others almost untouched — here's what the numbers actually say, method by method.By Phuoc Huynh
How Often Does USDA Update FoodData Central?USDA doesn't update its five FoodData Central datasets on one schedule — Branded Foods refreshes monthly while Foundation Foods ships twice a year. Here's the real cadence, and exactly which release this site is currently built on.By Phuoc Huynh
How to Build a Nutrient-Dense Plate Using Raw USDA DataUse actual per-calorie nutrient data instead of guesswork to decide what goes on your plate — here's the method, the real numbers, and the tool that applies it for you.By Phuoc Huynh
How to Read a Nutrition Facts Label (and What USDA Numbers Actually Mean)The label on a package and the USDA data behind this site are two different views of the same food — learn to read both without mixing up the numbers.By Phuoc Huynh
How USDA Actually Measures a Nutrient — Inside the Lab MethodsEvery nutrient number on this site traces back to a named laboratory technique, not a vague "lab tested" label — here's how USDA documents the chemistry, and how to read the method behind a number.By Phuoc Huynh
Micronutrient Deficiency Signs — What's Actually Backed by DataA plain-language rundown of what's actually documented about deficiency signs for eight key micronutrients — and why a symptom checklist can never replace a blood test.By Phuoc Huynh
Net Carbs, Total Carbs and Fiber: How to Read the Numbers"Net carbs" doesn't appear on any Nutrition Facts label and isn't an FDA-defined term — here's what the label actually measures, and how the subtraction works if you want to do it yourself.By Phuoc Huynh
Plant-Based vs. Animal Protein Sources: A Data ComparisonGram for gram, soy and peanuts beat several cuts of meat on protein content — the catch only shows up once you check what form the food is actually measured in.By Phuoc Huynh
RDA vs. Daily Value: What's the Difference?The number on a supplement bottle and the number on a food label come from two different federal frameworks — mixing them up can make a healthy diet look short on a nutrient it isn't, or vice versa.By Phuoc Huynh
Sodium, Potassium and Blood Pressure: What the Numbers SayIndividually, sodium and potassium each get their own reference page here — together, the ratio between them predicts blood pressure risk in a way neither number does alone.By Phuoc Huynh
Understanding Per-100g vs. Per-Serving Nutrition DataEvery nutrient value on this site is measured per 100 grams, not per serving — here's why USDA data works that way, and how to convert it yourself when you need an actual portion.By Phuoc Huynh
What 'Fortified' Actually Means in a Nutrient Database"Fortified" isn't a health claim on this site — it's a specific, trackable data pattern: a dedicated "added" nutrient field, a manufacturer-label-based source, and a real measured value. Here's what that looks like when you query it directly.By Phuoc Huynh