Reading a nutrition label
Read a label in under a minute: per 100 g versus per serving, the ingredients list, and the traffic-light colours.
THE TABLE
Two columns, two jobs
The nutrition table lists energy, fat, saturated fat, carbohydrate, sugars, often fibre, protein, and salt or sodium. Most labels give two columns. Per 100 g (or 100 ml for drinks) is for comparing products, because every product is measured on the same amount. Per serving tells you what you actually eat, if you eat the amount the maker had in mind.
Two yoghurts in different-sized pots: compare their per 100 g columns to see which has more sugar. Then look at per serving to know what one pot gives you.
Bag of crisps, 90 g
Label says: 150 kcal per serving
Serving size: 30 g
Servings in the bag = 90 ÷ 30 = 3
Whole bag = 150 × 3450 kcal if you eat the whole bag, not 150.The serving size is chosen by the maker, and it is often smaller than what people eat in one go. Always check how many servings the pack holds before you trust the per-serving numbers.
Check yourself
Maryam compares two breakfast cereals. Cereal A: 110 kcal per 30 g serving. Cereal B: 150 kcal per 45 g serving. Per 100 g, A is about 367 kcal and B about 333 kcal. What's the fair conclusion?
- A is lighter, because its serving has fewer kcal
- B has less energy per gram; the servings just differ in size
- They're the same, since both are cereals
- You can't compare them without eating both
Show the answer
B has less energy per gram; the servings just differ in size
Right. B's serving looks bigger in kcal only because its serving is 45 g instead of 30 g. Per 100 g, the same amount of each, B is the less energy-dense cereal.
Ingredients list
Every ingredient in the product, listed in descending order by weight at the time it was made: the first ingredient is the one there is most of, the last the one there is least of. If sugar is among the first three, the product is largely sugar.
"Wheat flour, sugar, vegetable oil, cocoa, salt": there is more sugar in this biscuit than oil, cocoa or salt, and only flour outweighs it.
Sugar goes by many names
- Words ending in -ose: sucrose, glucose, fructose, dextrose, maltose.
- Syrups: glucose syrup, glucose-fructose syrup, corn syrup, date syrup.
- Honey, molasses and fruit juice concentrate are sugars too.
- A maker can use three or four of these in small amounts, so none of them reaches the top of the list, even when together they would.
Check yourself
A granola lists "oats, glucose syrup, raisins, honey, sunflower oil, dextrose". Since oats come first, sugar can't be a big part of it.
Show the answer
False
False. Oats are the single biggest ingredient, but glucose syrup, raisins, honey and dextrose are all sugars or sugary. Split into four, they don't top the list, yet together they could weigh as much as the oats. Check the sugars line in the table.
FRONT OF PACK
Traffic-light labels
Many packs carry a small colour-coded panel on the front for fat, saturated fat, sugars and salt: green = low, amber = medium, red = high, per 100 g. The UK uses this scheme, and Iran has used a similar traffic-light style label on many packaged foods since about 2016, though the exact cut-offs can differ from country to country. Aim for mostly greens and ambers. An occasional red is fine; it tells you which foods to have less often or in smaller amounts.
A biscuit with red for sugars and amber for fat: a treat, not an everyday snack. Plain yoghurt with green across the board: an easy everyday choice.
UK thresholds, per 100 g of food (a worked example; other countries' cut-offs can differ):
| Per 100 g | Low (green) | High (red) |
|---|---|---|
| Sugars | 5 g or less | over 22.5 g |
| Fat | 3 g or less | over 17.5 g |
| Saturated fat | 1.5 g or less | over 5 g |
| Salt | 0.3 g or less | over 1.5 g |
Anything between the two columns is medium (amber).
Check yourself
Using the UK thresholds per 100 g, sort each value.
- Plain yoghurt: 4 g sugars
- Chocolate biscuit: 25 g sugars
- White cheese: 1.8 g salt
- Bread: 1.0 g salt
- Breakfast cereal: 12 g sugars
- Tinned chickpeas: 2.5 g fat
Show the answer
Low (green): Plain yoghurt: 4 g sugars, Tinned chickpeas: 2.5 g fat
Medium (amber): Bread: 1.0 g salt, Breakfast cereal: 12 g sugars
High (red): Chocolate biscuit: 25 g sugars, White cheese: 1.8 g salt
Check yourself
A packet of instant noodles lists 0.6 g sodium per serving, and no salt figure. About how much salt is that?
- About 0.24 g
- About 0.6 g
- About 1.5 g
- About 6 g
Show the answer
About 1.5 g
Yes. 0.6 × 2.5 = 1.5 g salt, close to a third of the WHO's under-5 g daily limit, from one serving.
What the front says, what the back shows
Front-of-pack claim
"No added sugar", "light", "natural", "high in fibre". Words chosen to sell. "No added sugar" juice can still be high in sugar from the fruit itself, and "light" only means lighter than the maker's usual version.
The table and the list
Numbers per 100 g and ingredients by weight, set out the same way on every product. Check any claim against them: sugars per 100 g, salt, saturated fat, and where sugar sits in the list.
Check yourself
A carton of juice says "No added sugar" in large letters. The table shows 10 g sugars per 100 ml. What's the best reading?
- It's sugar-free, so it's fine in any amount
- The claim is false and the label is illegal
- Nothing was added, but the juice still carries a fair amount of sugar from the fruit
- Sugars per 100 ml don't matter for drinks
Show the answer
Nothing was added, but the juice still carries a fair amount of sugar from the fruit
Right. The claim can be true and the drink still sugary: 10 g per 100 ml is about 25 g in a 250 ml glass, all from the fruit. The table tells you what the claim leaves out.
A label in under a minute
- Compare per 100 g
Holding two options? Put their per 100 g columns side by side: sugars, salt, saturated fat, fibre.
- Check the serving and the pack
How big is a serving, and how many are in the pack? Multiply if you'll eat more than one.
- Scan the first three ingredients
They make up most of the product. Look out for sugar under its other names.
- Glance at the colours
Mostly green and amber is an everyday food; several reds make it an occasional one.
Lesson recap
- Compare products per 100 g; use per serving to see what you actually eat, and check how many servings the pack holds.
- Ingredients are listed by weight, largest first. Sugar hides under many names, often split up.
- Traffic lights: green low, amber medium, red high. Under the UK scheme, over 22.5 g sugars or 1.5 g salt per 100 g is red.
- Salt ≈ sodium × 2.5. On %RI or %DV, 5 % or less is low and 20 % or more is high.
- Front-of-pack claims sell; the table and the ingredients list tell you what's inside.