How to Read a Food Nutrition Label: A Step-by-Step Guide

Nutrition labels differ between countries, but most share the same basic logic: they show how much energy and how many key nutrients are in a given amount of food so shoppers can compare products. In the United States, the Food and Drug Administration (FDA) requires a standardized "Nutrition Facts" panel on packaged food. In the European Union, Regulation (EU) No 1169/2011 requires a mandatory "nutrition declaration" on most pre-packed food, and the United Kingdom additionally promotes a voluntary front-of-pack "traffic light" system. This guide walks through the panel step by step, using the exact terms these official sources use.

Step 1: Start with the serving size

On the US label, every figure on the panel — calories, fat, sugar, sodium — refers to one serving, not the whole package, the FDA explains on its official guidance page. The agency notes the serving size "reflects the amount that people typically eat or drink" and is not a recommendation of how much to eat; if a package holds several servings, the listed amounts must be multiplied by however many servings are actually consumed.

The EU nutrition declaration is built differently: under Regulation 1169/2011, the core figures — energy, fat, saturates, carbohydrate, sugars, protein and salt — must be shown per 100 grams or per 100 millilitres, which makes it easier to compare two differently sized products side by side. Manufacturers may add a per-portion figure as well, under Article 33 of the regulation, but the per-100g/100ml figures are the mandatory, comparable ones.

Step 2: Read calories and the percentage columns

The FDA label states calories per serving and, for other nutrients, a "%DV" (percent Daily Value) column. According to the FDA, %DV shows how much a nutrient in one serving contributes to a general daily reference based on a 2,000-calorie diet, and the agency gives a simple rule of thumb: 5% DV or less counts as "low" in that nutrient, and 20% DV or more counts as "high."

The UK's official "Check the label" guidance describes an equivalent figure called "Reference Intake" percentages, which show how a product's nutrients fit into a recommended daily intake across the whole day, so shoppers can track consumption over several meals rather than judging one product in isolation.

Step 3: Check the nutrients linked to health risks

The FDA identifies saturated fat, sodium and added sugars as nutrients Americans generally consume too much of, and says eating too much of them is associated with higher risk of cardiovascular disease and high blood pressure. On the US label, saturated fat has a Daily Value of 20g, sodium of 2,300mg, and added sugars of 50g, each equal to 100% DV.

The FDA also distinguishes "Total Sugars," which includes sugar naturally present in foods like fruit and milk, from "Added Sugars," which are sugars added during processing; added sugars are shown as a subline "included" within total sugars. The World Health Organization's 2015 guideline on sugars intake recommends that free sugars make up less than 10% of total energy intake for both adults and children, and notes that cutting this further to below 5% of energy intake brings extra health benefits.

Step 4: Look for nutrients to get more of

On the US label, the FDA highlights dietary fiber, vitamin D, calcium, iron and potassium as nutrients many people do not get enough of, each carrying its own Daily Value (for example, 28g for fiber and 4,700mg for potassium) used to calculate %DV.

Step 5: Use colour-coded labels to compare at a glance

Many UK and some other European retailers add a voluntary front-of-pack traffic light label on top of the mandatory nutrition declaration. The UK government's official "Check the label" guidance explains that red means a food is high in that nutrient and should be cut down, eaten less often or in smaller amounts; amber means a medium level that can be eaten regularly; and green means a low amount, a generally healthier choice. The guidance suggests favouring products with more green or amber indicators and fewer red ones when comparing similar foods, while still checking Reference Intake percentages for a fuller daily picture.

Putting it together: a simple reading order

1. Check the serving size and how many servings are in the package before looking at any other number.
2. Note the calories per serving, and multiply by the number of servings you actually plan to eat.
3. Check the %DV or Reference Intake percentage for saturated fat, sodium/salt and sugars — the FDA's rule of thumb is 5% DV or less is low and 20% DV or more is high.
4. Separate added sugars from total sugars where the label distinguishes them, and compare against WHO's guidance of keeping free sugars under 10% of daily energy.
5. Look for fiber, vitamin D, calcium, iron and potassium figures if trying to increase intake of these nutrients.
6. If a traffic-light label is present, use it for a quick comparison, then check the percentage figures for a fuller picture across the day.

Because the exact format, reference values and mandatory nutrients differ by country, the practical approach is the same everywhere: identify what one serving or 100g actually represents, then use whatever percentage or color system the label provides to judge whether a nutrient is present in a small or large amount relative to a full day's intake.