How to read a nutrition label: serving size, sugars, salt and % reference intakes

Start with the serving size

• US labels give everything per serving, with the serving size and number of servings per container at the top. A bag of crisps or a bottle of drink may contain more than one serving.
• UK labels give values per 100g or 100ml, which makes it easy to compare products, and often per portion as well. The manufacturer's idea of a portion may be smaller than yours.
• If you eat twice the serving size, double everything.

Energy (calories)

The macronutrients

• Fat, with saturates (saturated fat) listed separately. Saturated fat is the one health advice suggests limiting.
• Carbohydrate, with sugars listed underneath. The sugars figure is part of the total carbohydrate, not in addition to it.
• Protein.
• Fibre: most people eat less than recommended, so a higher figure is generally a good sign. It is not always required on UK labels, so it may be missing.

Sugars vs added sugars

• UK "sugars" includes all sugars, whether naturally present (the lactose in milk, the sugars in fruit) or added. A plain yoghurt and a sweetened one can look similar until you check the ingredients.
• US labels show Total Sugars and, underneath, Added Sugars, which are the sugars put in during processing. That makes it easier to tell a naturally sweet food from a sweetened one.

Salt vs sodium

• UK labels show salt. US labels show sodium.
• Salt is sodium chloride, so the two are not the same number: multiply sodium by 2.5 to get the approximate salt equivalent. 400mg of sodium is about 1g of salt.

% Reference Intakes (UK) and % Daily Value (US)

• UK Reference Intakes (RIs) are guide amounts for an average adult: 2000 kcal of energy, 70g of fat, 20g of saturates, 260g of carbohydrate, 90g of sugars, 50g of protein and 6g of salt. For fat, saturates, sugars and salt these are amounts to stay under, not targets. A label saying a portion provides 25% of your RI for salt means a quarter of a day's guide amount.
• US % Daily Value (%DV) is also based on a 2,000-calorie day. A commonly used rule of thumb: 5% DV or less is low, 20% DV or more is high. Aim low for saturated fat, sodium and added sugars, and high for fibre, vitamins and minerals.
• Both are averages. Children, older adults and people who are very active, pregnant or managing a health condition may need different amounts.

Ingredients list

• Ingredients are listed in descending order of weight, so the first few make up most of the product.
• Sugar can appear under several names (glucose syrup, dextrose, honey, fruit juice concentrate and others). If several appear, the total may be higher than any single position suggests.
• In the UK and EU, the main allergens are emphasised in the list, usually in bold.

Front-of-pack labels

• UK traffic lights: many products show energy, fat, saturates, sugars and salt with red, amber or green colour coding and the % RI per portion. More greens is generally the healthier choice; a red is a signal to have it less often or in smaller amounts. The scheme is voluntary, so not every product uses it.
• US labels: front-of-pack claims such as "low fat" or "good source of fibre" have defined meanings, but they describe one nutrient only. Check the full panel.
• Health claims and packaging words like "natural" or "wholesome" are not a substitute for reading the numbers.

A quick routine in the shop

1. Check the serving size against what you will really eat.
2. Look at sugars (added sugars in the US), saturated fat and salt or sodium.
3. Compare per 100g between similar products.
4. Glance at the first three ingredients.