How to actually read a UK nutrition label

The back-of-pack nutrition table looks simple, but the two most common mistakes — comparing the wrong column, and trusting the front-of-pack colours blindly — lead people astray constantly.

Per 100g vs per portion: always check which one you're reading

UK labels are legally required to show values "per 100g" (or per 100ml for liquids), and usually also show a "per portion" column alongside it. These can tell very different stories. A cereal might look moderate in sugar per 100g, but if a "portion" is defined as a modest 30g and you actually eat double that, you're getting more sugar than the per-portion figure implies. When comparing two products, always compare the per-100g columns to each other — it's the only fair like-for-like comparison, since portion sizes are set by the manufacturer and vary between products.

The front-of-pack traffic lights are a simplification of the same data

Red/amber/green colours on the front are just a visual shortcut for the per-portion figures on the back, using fixed thresholds for fat, saturated fat, sugar, and salt. They're useful for a fast glance, but because they're calculated per portion, a product with an unusually small stated portion size can show more green lights than its per-100g nutrition profile would suggest.

Reference intakes are averages, not targets

You'll often see a "%RI" (reference intake) figure — this represents what percentage of an average adult's daily recommended intake that portion provides, based on a notional 2,000 kcal/day diet. It's a genuinely useful proportionality check, but it's calculated for a generic adult, not you specifically — your own needs vary by age, activity level, and health circumstances.

Ingredients are listed by weight, highest first

The ingredients list is ordered by proportion, heaviest first. If sugar (or one of its many aliases — glucose syrup, fructose, dextrose, invert sugar syrup) appears in the first two or three ingredients, it's a significant proportion of the product by weight, even if the nutrition table's sugar row doesn't immediately jump out at you.

The quickest way to skip all of this

None of this is complicated once you know what to look for, but it does take a minute of actual reading per product — and most people are standing in a supermarket aisle, not sitting down with a calculator. That's the entire reason Olive Avocado exists: scan the barcode, and it pulls the per-100g figures itself, checks them against what you've said you personally care about, and gives you a straight answer instead of a table to interpret.