Traffic-Light Food Labels Explained
How the UK front-of-pack traffic-light label works: the red, amber and green cut-offs per 100 g, the portion rule, %RI and what the colours leave out.
Many packs sold in the UK carry a small panel on the front listing energy, fat, saturates, sugars and salt, often in red, amber and green. This is the UK front-of-pack (FoP) nutrition label, usually called the traffic-light label. This guide explains what each part means, how the colours are worked out and where the system has limits.
Where the label comes from
The format is set out in government guidance, the Guide to creating a front of pack (FoP) nutrition label for pre-packed products sold through retail outlets. It was developed by the Department of Health, the Food Standards Agency (FSA) and the devolved administrations together with the British Retail Consortium, and was last updated in 2016. It builds on the food information rules in Regulation (EU) No 1169/2011, which still apply in Great Britain as assimilated law.
The scheme is voluntary. Each business decides whether to use it and on which products, so a pack without traffic lights tells you nothing about the food inside. The nutrition table on the back of the pack is a different matter: it is mandatory on most pre-packed foods. Our guide to reading a UK nutrition label covers it line by line.
What the label shows
A full front-of-pack label has five parts:
- Energy, in kilojoules (kJ) and kilocalories (kcal).
- Fat, saturates, sugars and salt, in grams.
The guidance also allows an energy-only version. Values can be given per 100 g or 100 ml, per portion, or both. When the four nutrients are shown per portion only, energy must also be shown per 100 g or 100 ml, so products can still be compared.
Many labels also show the percentage of the reference intake (%RI) that a portion provides, usually next to the statement "Reference intake of an average adult (8400 kJ / 2000 kcal)". The reference intakes used are:
- Energy: 8400 kJ / 2000 kcal
- Fat: 70 g
- Saturates: 20 g
- Sugars: 90 g
- Salt: 6 g
Reference intakes are a benchmark for an average adult, not a personal target. The NHS describes them as guidelines for the approximate amount of energy and nutrients needed for a healthy diet; actual needs depend on age, sex, size and activity.
Two details are easy to miss. "Sugars" on the label means total sugars, including the sugars naturally present in milk and fruit, not just added sugar. "Salt" covers sodium from all sources, calculated as sodium multiplied by 2.5.
How the colours are decided
Colours apply to fat, saturates, sugars and salt. Energy is not colour coded. Each nutrient is compared with fixed cut-offs per 100 g of food or per 100 ml of drink: green (low) at or below the low cut-off, red (high) above the high cut-off, and amber (medium) in between. Some labels also print the words LOW, MED or HIGH.
| Per 100 g of food | Green (low) | Amber (medium) | Red (high) |
|---|---|---|---|
| Fat | 3.0 g or less | more than 3.0 g up to 17.5 g | more than 17.5 g |
| Saturates | 1.5 g or less | more than 1.5 g up to 5.0 g | more than 5.0 g |
| Sugars | 5.0 g or less | more than 5.0 g up to 22.5 g | more than 22.5 g |
| Salt | 0.3 g or less | more than 0.3 g up to 1.5 g | more than 1.5 g |
| Per 100 ml of drink | Green (low) | Amber (medium) | Red (high) |
|---|---|---|---|
| Fat | 1.5 g or less | more than 1.5 g up to 8.75 g | more than 8.75 g |
| Saturates | 0.75 g or less | more than 0.75 g up to 2.5 g | more than 2.5 g |
| Sugars | 2.5 g or less | more than 2.5 g up to 11.25 g | more than 11.25 g |
| Salt | 0.3 g or less | more than 0.3 g up to 0.75 g | more than 0.75 g |
The portion rule
Large portions get an extra check. For foods sold in portions of more than 100 g, and drinks in portions of more than 150 ml, a nutrient is red whenever one portion provides more than 30% (food) or 15% (drinks) of its reference intake, whatever the per-100 g value. For food that means more than 21 g of fat, 6.0 g of saturates, 27 g of sugars or 1.8 g of salt per portion; for drinks, more than 10.5 g, 3.0 g, 13.5 g or 0.9 g.
Using the label in the shop
- Compare like with like. Use the per-100 g figures to compare two products, and the per-portion figures to see what you actually eat. A manufacturer's idea of a portion may be smaller or larger than yours.
- Look at the overall pattern. The NHS says that a food or drink with all or mostly green on the label is generally a healthier choice, and suggests going for more greens and ambers and fewer reds.
- Read the colour in context. Cooking oils, nuts and hard cheese often show amber or red for fat because fat is what they mainly are. The colours describe the amount of a nutrient, not the role a food plays in a balanced diet.
- Check where the sugars come from. Because the sugars colour uses total sugars, plain yoghurt or a fruit-based snack can show amber from naturally present sugars. Our guide to free sugars and total sugars explains how to tell the difference.
What the traffic lights do not tell you
The label covers five numbers and nothing else. It says nothing about fibre, protein, wholegrains, fruit and vegetable content, vitamins or minerals, and nothing about how processed a food is or which additives it contains. It is also separate from the rules on foods high in fat, salt or sugar, which use a different scoring system; see our guide to HFSS rules.
How FoodFact shows traffic-light colours
On FoodFact product pages we calculate the traffic-light colours ourselves from the per-100 g or per-100 ml values declared for each product, using the cut-offs above and the portion rule where a portion size is declared. These colours are our calculation, not a statement about what is printed on a particular pack, which may show different values or no front-of-pack label at all. You can browse our lower-sugar and lower saturated fat lists, or put two products side by side with the comparison tool. Recipes change, so the pack in your hand is always the final word.