Guide
How to compare two foods fairly
Compare two foods on the same basis: per 100 g to see which is richer or leaner, per serving to see what a portion gives, and against the Daily Value to see what matters. Then look at the whole label, not one number.
Published · By GetFoodFacts · the rules are cited to FDA and USDA, the figures computed from USDA FoodData Central (April 30, 2026 release)
1. Pick one basis
Serving sizes differ between labels (the same aisle can hold hundreds of sizes), so a per-serving comparison can compare different amounts. Per 100 g compares like with like; per serving answers "what does my portion give". Use per 100 g to choose, per serving to plan.
2. Compare the nutrients that matter
A 20% difference on a nutrient with a large Daily Value can be a few milligrams. GetFoodFacts's compare pages name a difference only when one food has at least 20% more and the gap is at least 2% of the Daily Value.
3. Compare the same form
Raw and cooked, drained and packed in oil, dry and prepared: USDA lists them separately because the numbers differ, sometimes several times over. Cooked rice has about a third of the calories of dry rice per 100 g because it holds water.
4. Place each food in its aisle
A product page shows where the product sits among every product of its kind: "less sugar per 100 g than 80% of the yogurts in the database" says more than the number alone.
Serving sizes: why two labels differ
Sources for this page
- USDA FoodData Central
- the food and product records, April 30, 2026 release. fdc.nal.usda.gov
- USDA Food and Nutrient Database for Dietary Studies
- the survey foods and their portions. ars.usda.gov
- 21 CFR 101.9, Nutrition labeling of food
- the label format, rounding and Daily Values. ecfr.gov
- 21 CFR 101.12, Reference amounts customarily consumed
- the serving each kind of food is labeled by. ecfr.gov
- FDA, Daily Value on the Nutrition and Supplement Facts Labels
- the Daily Values in a table. fda.gov