How to read a nutrition label, and what the numbers can’t tell you

What is on a Nutrition Facts panel?

A Nutrition Facts panel shows the serving, the calories and nutrients in one serving with their % Daily Value, and a footnote. The ingredient list and allergens sit next to it.

Why start with the serving size?

Every number on the panel refers to one serving, so the serving size comes first. In its guide to the label, the US Food and Drug Administration explains that serving sizes are standardized so similar foods can be compared. The serving size “reflects the amount that people typically eat or drink. It is not a recommendation of how much you should eat or drink.” All the nutrient amounts, including calories, refer to that serving.

The most common way to misread a label is to take a per-serving figure as the figure for the whole package. Checking the servings-per-container line first prevents it.

What does % Daily Value mean?

The % Daily Value column shows how much one serving contributes toward a reference amount used for labeling. The footnote required by 21 CFR 101.9 states it directly: “The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.”

The FDA’s general guide is that 5% DV or less of a nutrient per serving is considered low and 20% DV or more is considered high. Those two thresholds make the column a quick way to compare two products. The column is not a statement of what your own day should contain.

How exact are the numbers on a nutrition label?

Label numbers are close, not exact. Two separate rules sit behind every figure: rounding and compliance ranges.

Rounding. Values are declared in set increments. For example:

Compliance ranges. Under 21 CFR 101.9(g), FDA checks a label against a composite of 12 consumer units, taken one from each of 12 randomly chosen shipping cases. A vitamin, mineral, protein or fiber added to fortify a food must be at least the declared amount. When that nutrient occurs naturally in the food, the composite must reach at least 80% of the declared value. Some nutrients must not exceed the declared value by more than 20%: calories, total sugars, total, saturated and trans fat, cholesterol and sodium, and added sugars when they are the only sugars in the food. The rule also allows for the normal variability of the laboratory method used.

How do you spot added sugars and allergens?

Added sugars have their own indented line on the panel. Major allergens are named in the ingredient list or in a Contains statement beside it.

Under 21 CFR 101.4, ingredients are listed “in descending order of predominance by weight”, so the first ingredient is the heaviest. Ingredients present at 2% or less may be grouped at the end under a statement such as “Contains 2 percent or less of”. Several different sugars listed separately can together outweigh an ingredient sitting above each of them.

Added sugars appear on the panel as their own line, indented under Total Sugars and “prefaced with the word ‘Includes’ followed by the amount”, according to 21 CFR 101.9.

For allergens, the FDA lists nine major food allergens: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and, since January 1, 2023, sesame. A major allergen must be declared either in parentheses after the ingredient, such as “whey (milk)”, or in a “Contains” statement next to the ingredient list. The FDA also notes that you may still find products for sale that do not list sesame as an allergen.

Where does most sodium come from?

The FDA says most dietary sodium, over 70%, comes from packaged and prepared foods rather than salt added at the table or in cooking. Citing the Centers for Disease Control and Prevention, it lists foods that supply about 40% of the sodium Americans consume, including deli meat sandwiches, pizza, burritos and tacos, soups and savory snacks. The FDA adds that foods eaten several times a day, such as breads, can add up to a lot of sodium even when one serving is not high in it.

What do “light” and “healthy” mean on a package?

Both words have precise legal definitions in the US. Under 21 CFR 101.56, “light” on a food deriving half or more of its calories from fat means 50% less fat than a reference food. Otherwise it means a third fewer calories or 50% less fat. Under 21 CFR 101.65, a food labeled “healthy” must contain set amounts from food groups and stay within limits on added sugars, sodium and saturated fat. The panel and the ingredient list are still the places to read what is actually in the food.

What the labeling rules establish