How to Read a UK Food Label in 60 Seconds

What UK food labels are required to show

Under the Food Information Regulations 2014 (the UK's version of EU Regulation 1169/2011), pre-packed food sold in the UK must include a nutrition declaration showing energy (kJ and kcal), fat, saturated fat, carbohydrate, sugars, protein, and salt — both per 100g (or per 100ml for liquids) and, optionally, per portion. The ingredient list, allergen information, and a product name are also mandatory.

The traffic light label on the front of pack is voluntary, but most major UK retailers and manufacturers use it. It was developed by the Food Standards Agency (FSA) to give shoppers a quick visual summary without needing to study the numbers.

Here's how to make sense of each element — starting with the fastest one.

The traffic light system: red, amber, and green

The front-of-pack traffic light label uses colour coding for four nutrients: fat, saturated fat, sugar, and salt. Each gets a colour based on how much the food contains per 100g:

• Green (low) — This nutrient is at a low level. You can eat these foods freely as part of a balanced diet.
• Amber (medium) — A moderate amount. Fine for most people, but watch your overall intake across the day.
• Red (high) — This nutrient is high. It doesn't mean you must avoid the food, but eat it less often or in smaller amounts.

The FSA's guidance is simple: try to choose products with more greens and ambers, and fewer reds. If a product has one or more red lights, it's worth asking whether there's a similar product with amber or green instead.

Traffic light thresholds (per 100g)

These are the FSA's thresholds for solid foods. The numbers differ slightly for drinks (which use per-100ml thresholds), but the principle is the same.

Per 100g vs per serving — which column matters?

Every nutrition label includes a "per 100g" column. Many also include a "per serving" column. Both are useful, but they answer different questions:

• Per 100g — Best for comparing products. Because it's a fixed amount, you're comparing like with like. Two different pasta sauces? Compare their per-100g sugar and salt, and you'll see which is lower, regardless of jar size or suggested serving.
• Per serving — Best for understanding what you'll actually eat. If you're pouring yourself a bowl of cereal, the per-serving column tells you roughly what's going into your body.

The catch with per-serving figures is that serving sizes vary between brands and aren't regulated to a standard amount. One brand's "serving" of granola might be 40g while another's is 60g. This makes per-serving numbers unreliable for side-by-side comparisons. The FSA's traffic light system is based on per-100g values precisely for this reason.

Reading the ingredient list

The ingredient list is where you find out what's actually in the product. Under UK food law, ingredients must be listed in descending order by weight at the time of manufacture. The first ingredient is what the product contains the most of; the last is the least.

This matters more than people realise. A "strawberry yoghurt" where the first three ingredients are milk, sugar, and cream — with strawberries listed fifth — contains far less fruit than you might expect. Conversely, if the first ingredient is strawberries, you know fruit genuinely dominates the recipe.

How to spot hidden sugars

Manufacturers sometimes use multiple types of sugar so that no single sugar appears near the top of the list. Look for any of these — they are all forms of added sugar:

• Glucose syrup
• Dextrose
• Maltodextrin
• Fructose
• Sucrose
• Maltose
• Corn syrup / high-fructose corn syrup
• Invert sugar
• Hydrolysed starch
• Honey, agave syrup, maple syrup
• Concentrated fruit juice (when used as a sweetener)

If you see three or four of these in one ingredient list, the product's total sugar content is likely higher than any single entry would suggest. Cross-reference with the "of which sugars" line in the nutrition table to see the full picture.

How to spot hidden salt

Salt can appear under several names too:

• Sodium chloride
• Monosodium glutamate (MSG)
• Sodium bicarbonate
• Sodium nitrite / sodium nitrate (in cured meats)
• Soy sauce, fish sauce

The nutrition label shows total salt content, so you don't need to calculate it from sodium. The FSA recommends adults consume no more than 6g of salt per day. A single red-rated ready meal can contain 2-3g — half your daily limit.

Reference Intakes (RI) and % of daily intake

Many labels show Reference Intakes (RI) — previously called Guideline Daily Amounts (GDAs). These tell you what percentage of an average adult's daily guideline amount one serving provides.

The Reference Intakes are based on:

These are based on an average adult woman. Your actual needs will vary depending on your age, sex, weight, and activity level. A physically active man, for example, might need 2,500 kcal or more. RIs are a rough guide, not a personal target.

The % RI figures appear on the front of pack (usually in a row of small thumbnails) and on the back. If a single serving provides 35% of your RI for salt, you know it's making a significant dent in your daily allowance.

Allergen labelling and Natasha's Law

UK food law requires that the 14 major allergens are highlighted in the ingredient list — typically in bold, though some manufacturers use underlining, italics, or capitals. The 14 allergens are:

1. Celery
2. Cereals containing gluten (wheat, rye, barley, oats)
3. Crustaceans
4. Eggs
5. Fish
6. Lupin
7. Milk
8. Molluscs
9. Mustard
10. Nuts (almonds, hazelnuts, walnuts, cashews, pecans, brazils, pistachios, macadamias)
11. Peanuts
12. Sesame
13. Soybeans
14. Sulphur dioxide and sulphites (at levels above 10mg/kg or 10mg/L)

Natasha's Law (the UK Food Information Amendment), which came into force in October 2021, extended these requirements to food that is prepacked for direct sale (PPDS) — such as sandwiches made and wrapped on the premises in shops, delis, and cafes. Before this law, such items didn't need a full ingredient list.

The law was introduced following the death of Natasha Ednan-Laperouse, who suffered a fatal allergic reaction after eating a Pret A Manger baguette that contained sesame but had no ingredient labelling.

E-numbers on labels: what the codes mean

E-numbers are standardised codes for food additives that have been assessed and approved for use in the EU and UK by the European Food Safety Authority (EFSA). The "E" stands for Europe. If an additive has an E-number, it means it has passed safety testing — though the level of scrutiny and public perception varies.

The numbering system is organised into categories:

• E100-E199 — Colours (e.g., E100 = curcumin, E160a = carotenes)
• E200-E299 — Preservatives (e.g., E202 = potassium sorbate, E250 = sodium nitrite)
• E300-E399 — Antioxidants and acidity regulators (e.g., E300 = vitamin C, E330 = citric acid)
• E400-E499 — Thickeners, stabilisers, and emulsifiers (e.g., E412 = guar gum, E471 = mono- and diglycerides)
• E500-E599 — Acidity regulators and anti-caking agents (e.g., E500 = sodium bicarbonate)
• E600-E699 — Flavour enhancers (e.g., E621 = monosodium glutamate)
• E900-E999 — Sweeteners, gases, and waxes (e.g., E950 = acesulfame K, E951 = aspartame)

Many E-numbers are entirely natural and harmless — E300 is ascorbic acid (vitamin C), E330 is citric acid (found in citrus fruits), and E410 is locust bean gum (from carob seeds). Others are more controversial, particularly certain artificial colours and preservatives. The key is to know what you're looking at rather than assuming all E-numbers are bad.

For a full lookup, see our guide to E-numbers or use NutraSafe's food additive scanner to check any E-number instantly.

5 things to check in 60 seconds

You don't need to study the entire label every time you pick something up. Here's a practical 60-second checklist:

1. Traffic lights (5 seconds) — Glance at the front-of-pack colours. More greens and ambers? Good. Multiple reds? Consider an alternative or smaller portions.
2. Per-100g column (10 seconds) — If comparing two products, look at fat, sugar, and salt per 100g. Lower numbers win. Ignore the per-serving column for comparisons.
3. First three ingredients (10 seconds) — The first three ingredients make up the bulk of the product. Are they what you'd expect? Wholegrains, meat, vegetables — or sugar, palm oil, and modified starch?
4. Allergens in bold (5 seconds) — If you or someone you're cooking for has allergies, scan the ingredient list for bold text. This is legally required for the 14 major allergens.
5. % Reference Intake (5 seconds) — Check the % RI for any nutrients you're watching. If a single serving hits 30%+ of your salt or sugar RI, factor that into the rest of your day.

That's 35 seconds. You have 25 to spare.

Frequently asked questions

What do the traffic light colours on UK food labels mean?

The traffic light system uses red, amber, and green to show whether a food is high, medium, or low in fat, saturated fat, sugar, and salt per 100g. Green means low (eat freely), amber means medium (fine for most people), and red means high (eat less often or in smaller amounts). For example, more than 17.5g of fat per 100g triggers a red light, while 3g or less is green.

Should I look at the per-100g or per-serving column on food labels?

Use per 100g for comparing products and per serving for understanding what you'll actually eat. The per-100g column is the fairest comparison because serving sizes vary between brands — one brand's "serving" of cereal might be 30g while another's is 45g. The FSA's traffic light system is based on per-100g values for this reason.

How can I spot hidden sugars on a food label?

Check the ingredient list for alternative names: glucose syrup, dextrose, maltodextrin, fructose, sucrose, maltose, corn syrup, invert sugar, hydrolysed starch, and honey are all forms of added sugar. If several appear in the same product, it likely contains more added sugar than a single entry would suggest. Also check the "of which sugars" line in the nutrition table.

What are Reference Intakes on UK food labels?

Reference Intakes (RI) show what percentage of your daily guideline amount one serving provides. They're based on an average adult consuming 2,000 kcal per day: 70g fat, 20g saturated fat, 90g sugar, and 6g salt. They appear as percentages on the front or back of pack. RIs are guidelines, not personal targets — your actual needs may differ based on age, sex, and activity level.

What are E-numbers on food labels and are they safe?

E-numbers are codes for food additives that have been tested and approved for use in the EU and UK. The "E" stands for Europe. They cover colours (E100-E199), preservatives (E200-E299), antioxidants (E300-E399), and emulsifiers/stabilisers (E400-E499). Having an E-number means the additive has passed safety assessments by EFSA. Some are entirely natural — for example, E300 is vitamin C and E330 is citric acid. For a quick check, try our food additive scanner.

Related articles

• How to Read Food Labels UK (Landing Page)
• UK Food Label Traffic Light System Explained
• What Are E-Numbers? A Plain-English UK Guide
• Ultra-Processed Food in the UK: What It Is and Why It Matters
• Food Additive Scanner UK
• How to Use a Food Scanner App

Last reviewed and updated: 7 February 2026