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Most UK food packs carry a traffic-light label on the front. Learn three numbers and you can judge sugar, fat and salt in a few seconds, without a calculator.
The traffic-light label in 10 seconds
Green means low, amber means medium and red means high. A pack that is mostly green and amber is a good everyday choice. Any red means that food is best eaten less often or in smaller amounts.
These are the NHS thresholds per 100g of food:
| Per 100g | Low (green) | High (red) |
|---|---|---|
| Total fat | 3g or less | More than 17.5g |
| Saturated fat | 1.5g or less | More than 5g |
| Sugars | 5g or less | More than 22.5g |
| Salt | 0.3g or less | More than 1.5g |
Anything between the two columns is amber. Drinks use different thresholds, so treat these figures as a guide for food.
Always compare per 100g, not per portion
Manufacturers choose their own portion sizes, and they are often smaller than what people really eat. When you compare two cereals or two yoghurts, use the per 100g column. It’s the only fair comparison.
Quick tip: if you’d eat twice the “portion” on the pack, double every number on the front label.
Spot hidden sugar in the ingredients
Ingredients are listed by weight, with the biggest first. Sugar often hides under other names, and a product can use several of them so none appears near the top. Look out for:
- glucose, fructose, sucrose, dextrose, maltose
- corn syrup and high-fructose corn syrup
- honey, molasses, treacle, maple syrup and agave syrup
- fruit juice concentrate and fruit purées
- cane sugar and brown sugar
UK guidance says adults should have no more than 30g of free sugars a day, about 7 sugar cubes. Free sugars include sugar added to food and the sugar in honey, syrups and fruit juice. They don’t include the sugar naturally found in whole fruit, vegetables and milk.
Why “total sugars” can mislead
The label shows total sugars, which mixes natural and added sugar. A plain yoghurt shows some sugar from milk, which is fine. A fruit yoghurt might show double that because of added sugar. Check the ingredients list to tell them apart.
Skip foods labelled “diabetic”
Diabetes UK advises against foods sold as “diabetic”. They have no proven benefit, they often cost more, and some are still high in fat and calories. A normal, balanced choice is better.
When there is no label
Restaurant meals, takeaways and home cooking don’t come with a traffic light. That’s where most of us guess. Fill half the plate with vegetables or salad, keep starchy carbs to about a quarter, and choose grilled over fried where you can.
You can also photograph the plate with an app such as Dietary Insight. It estimates the sugar, salt and fat in the meal and flags anything that clashes with your health profile.
The 3-second checklist
- Look for red on the front. More red means “sometimes”, not “every day”.
- Compare similar products using the per 100g figures.
- Scan the first three ingredients for sugar under another name.
Frequently asked questions
What is a high amount of sugar on a UK food label?
More than 22.5g of total sugars per 100g is high (red). 5g or less per 100g is low (green). Anything in between is medium (amber).
How much free sugar should adults have a day?
UK guidance says adults should have no more than 30g of free sugars a day, which is about 7 sugar cubes.
Should I buy foods labelled 'diabetic'?
No. Diabetes UK says foods labelled 'diabetic' have no proven benefit over a balanced diet. They can be expensive and still high in fat or calories.
Sources
This article is general information, not medical advice. If you have diabetes, high blood pressure or a food allergy, speak to your GP, diabetes nurse or a registered dietitian before changing your diet or medication. Read our medical disclaimer.