Understanding Food Labels

This final lesson brings the course together. You'll learn how to read a nutrition label, what ingredient lists and allergen information tell you, and why labels look different depending on the country.

Read the original sources

Labels differ by country

There is no single worldwide food label. This lesson compares UK/EU conventions with US conventions because they are widely seen, but other countries have their own rules. Always check what applies where you live.

Per 100g, per 100ml and per serving

UK and EU nutrition tables are shown per 100g (or per 100ml for drinks), and may also show values per portion.
US Nutrition Facts labels are based on a stated serving size, shown at the top of the label.

Per-100g values are useful for comparing products fairly. Per-serving values tell you about the amount the manufacturer has chosen, which may not match what you eat.

The nutrients listed

How common label lines differ. Simplified; see the official sources for full rules.
Topic	UK / EU	US
Energy	kJ and kcal	Calories
Fat	Fat, of which saturates	Total Fat, Saturated Fat, Trans Fat
Carbohydrate	Carbohydrate, of which sugars; fibre, if shown, listed separately	Total Carbohydrate, including Dietary Fiber, Total Sugars and Added Sugars
Protein	Protein	Protein
Salt / sodium	Salt	Sodium

Salt and sodium are not the same number: salt is sodium chloride, so a salt figure is larger than the sodium it contains. Make sure you're comparing like with like. For the energy, protein, carbohydrate and fat lines, see Lessons 2, 3, 4 and 5.

Ingredient lists and allergens

Ingredients are listed in descending order by weight, so the first ingredients make up the largest share of the product. This is the case in the UK, EU and US.

Allergens (rules vary by country)

In the UK and EU, pre-packed foods must list ingredients with specified allergens emphasised, for example highlighted in bold. In the US, major food allergens must be declared on the label, either in the ingredient list or in a “Contains” statement. The list of allergens covered differs between countries.

If you or someone you cook for has a food allergy, follow the advice of your healthcare professional and your national food safety authority.

Front-of-pack labels

Many products also carry a simplified label on the front of the pack. These schemes vary:

UK: a voluntary front-of-pack scheme shows energy, fat, saturates, sugars and salt, often with reference intakes. Many labels use red, amber and green colour coding to show at a glance whether fat, saturates, sugars and salt are high, medium or low.
Some other European countries use different schemes, such as Nutri-Score.
US: front-of-pack information is set by manufacturers and FDA rules, and differs from UK and European schemes.

Front-of-pack labels are a quick guide, but the full nutrition table and ingredient list give more detail.

Comparing two products

Hypothetical comparison

Two fictional yoghurts: Yoghurt A has 12g sugars per 100g in a 150g pot. Yoghurt B has 8g sugars per 100g in a 200g pot.

Per 100g, A has more sugars than B (12g vs 8g).
Per pot: A = 12 ÷ 100 × 150 = 18g; B = 8 ÷ 100 × 200 = 16g.

These products are invented for learning. Comparing per 100g shows which is lower in sugars; comparing per pot shows what you actually eat.

Try it yourself (hypothetical food)

A fictional drink label shows 5g sugars per 100ml. How many grams of sugars are in a 330ml can?

Use (sugars per 100ml ÷ 100) × millilitres.

Common label traps

Different serving sizes: two products can list different portions, so per-serving figures can't be compared directly. Use per-100g values where available.
Packs with several servings: a pack may contain more than one serving; the figures may apply to only part of it.
Salt vs sodium: they're different numbers for the same component.
Reference percentages: %RI (UK/EU) and %DV (US) use different reference amounts and are not personal targets.
Claims on the front: words like “light” or “high protein” are regulated differently in different countries. Check the nutrition table.

Practise with real foods

Use the calculator to see nutrient values from USDA FoodData Central and compare portions.

Open the Food Calorie Calculator

Lesson summary

Label rules differ by country; UK/EU and US are compared here, but neither is universal.
UK/EU tables are per 100g/100ml; US labels are per serving.
Check whether a label shows salt or sodium, and how carbohydrate and fibre are counted.
Ingredients are listed by weight; allergen rules vary by country.
Front-of-pack schemes are quick guides; the full table gives more detail.
Watch for serving-size differences when comparing products.