How to read a nutrition label

First, know which column you are reading

Under EU rules (Regulation 1169/2011) the nutrition declaration must give values per 100 grams or per 100 millilitres. A per-portion column is optional. So the first number you see on a pack is very likely the 100-gram figure rather than the pack total.

The gap is not small. For a 250-gram pack:

Number shown	What it means	Whole pack
480 kcal	per 100 g	1,200 kcal
480 kcal	per portion (50 g)	2,400 kcal

The order of the seven rows is fixed too: energy, fat, saturates, carbohydrate, sugars, protein, salt. Always that order. Whichever brand you pick up, the row you want sits in the same place, and that rigidity is what makes label reading fast once your eye has learned the layout.

Step one is reading the heading above the number. Step two is finding the net weight and scaling. When a gram conversion is what you actually need, the portion converter handles cups, spoons and grams.

The portion trap

Manufacturers choose their own portion size. A crisp packet can declare a 30-gram portion; nobody has ever seen a crisp packet abandoned at 30 grams. If two brands in the same category declare different portions, the two numbers you placed side by side were never comparable to begin with.

The rule is simple: always compare using the 100-gram column. The portion column only answers “how much will I eat”, and it earns its place only when the grams in it are yours rather than the manufacturer’s.

The American label is built the opposite way round. Its Nutrition Facts panel is written per serving and carries no 100-gram column at all, so comparing the same product across the two continents without noticing the difference makes a formatting choice look like a difference in the food.

The number is a range, not a point

The values in the table are not measured on every batch. The regulation allows three routes: laboratory analysis of the product, calculation from the known values of the ingredients, or derivation from generally established data tables — and for foods with natural ingredients, where season, ripeness, feed, soil and growing conditions shift the same product from batch to batch, the third route is not necessarily worse than the first.

Enforcement therefore works with a tolerance band, and it is a wide one: the Commission’s guidance accepts a deviation of roughly ±20% for most nutrients. A product labelled 480 kcal may really sit anywhere between 400 and 570. That is not a loophole. It is what measuring food is like.

The energy row is also a calculation rather than a measurement. Carbohydrate and protein count as 4 kcal per gram, fat as 9, fibre as 2 and polyols as 2.4, and the total falls out of those fixed factors — which means that in products high in fibre or polyols, typically sugar-free chocolate and protein bars, the energy figure on the label is less a calorimeter reading than an accounting decision.

None of this means labels lie. It means a 5% difference between two products disappears into the noise, while a 40% difference is real.

Who the reference intake percentages are for

The “%RI” or “reference intake” column is calculated for an average adult consuming 2,000 kcal and 8,400 kJ a day. It is a shared yardstick, not a target. For someone who needs 1,600 kcal every percentage there understates the load; for someone on 2,800 it overstates it.

Translating those percentages into your own terms requires knowing your own daily calories. Without that number the column is useful only for comparing one product against another.

Sugars, added sugars and carbohydrate

The “of which sugars” line beneath carbohydrate shows total sugars: the fruit’s own sugar and the sugar stirred in later land in the same figure. Plain yoghurt also declares some sugar (lactose), and that is not a fault.

Working out how much was added means reading the ingredients list instead of the table. Syrup, glucose-fructose syrup, dextrose, maltodextrin, concentrated fruit juice — every one of them is added sugar. When several appear at once, no single one has to climb to the top of the list even though together they might outweigh whatever does.

The European label has no separate added-sugars row. The American panel has required one since 2020, and that single line does exactly the work you are otherwise forced to do by hand.

The ingredients list is ordered by weight

The list is not arbitrary: it runs from most to least by weight. The first three entries tell you what the product actually is. If a loaf sold as wholegrain lists white wheat flour first, the wholegrain is further down and in the minority.

There is also quantitative declaration: any ingredient highlighted in the product name or on the picture must have its percentage stated in the list. On a pack of hazelnut wafers the hazelnut percentage is right there, and it is usually smaller than the picture suggests.

Words set in bold or capitals inside the list are not decoration. The fourteen allergen groups must be typographically separated from everything around them, and that formatting is the only place you need to look when scanning a product for allergens.

The salt row is not sodium

European labels declare salt, not sodium, and the conversion is fixed: sodium × 2.5 = salt. Comparing a table written in sodium — American packs, older stock — against a European one without applying that factor makes the same product look two and a half times different.

The recommended ceiling for adults is 5 grams of salt a day. On processed products, above 1 gram per 100 grams counts as high and under 0.3 grams as low.

Nutrition claims have fixed meanings

“Low fat”, “no added sugar” and “high fibre” read like marketing, yet Regulation 1924/2006 ties each of them to a number:

• Low fat: under 3 g fat per 100 g (1.5 g/100 ml for liquids)
• Sugar-free: under 0.5 g sugar per 100 g
• Source of fibre: at least 3 g per 100 g; high fibre needs 6 g
• Source of protein: at least 12% of energy from protein; high protein needs 20%

“No added sugar” says no sugar was added — not that the product contains none. Something sweetened with fruit concentrate can carry the phrase and still declare a high figure on the sugars row.

Then there are the words with no definition at all: natural, homemade, traditional, fit. None of them has a numeric threshold and none of them is enforced.

The practical approach is to ignore the claim on the front and read the table on the back. A true claim shows up there anyway.

A fast reading order

1. Column heading: per 100 g, or per portion?
2. Net weight of the pack, and how much you will genuinely eat
3. Calories and protein — the two rows that decide fullness and progress
4. The sugars row, then the first three items in the ingredients list
5. Any comparison, always on the 100-gram basis

Rather than doing this by hand on every pack, you can hand the table to the label interpreter and have it converted to your own portion; the tools below run the same arithmetic.