High protein vs source of protein: the GB label rules
Protein claims depend on the share of energy from protein, not simply the grams printed on the front. Work through two example labels.
On this page
A food can contain several grams of protein without qualifying as high protein. In Great Britain, the relevant calculation is how much of its energy comes from protein.
The two thresholds
The GB nutrition claims register, in its nutrition claims sheet, sets these conditions:
| Claim | Minimum share of the food's energy supplied by protein |
|---|---|
| Source of protein | 12% |
| High protein | 20% |
These rules apply to England, Scotland and Wales. Northern Ireland uses the EU framework; the European Commission's claim list gives the corresponding conditions. This guide explains the claim, rather than certifying a particular product.
Try the calculation
For a practical check using the kcal figure, multiply protein grams by 4, divide by total kcal, then multiply by 100. Use values from the same amount of food throughout.
Imagine a fictional snack with 8g protein and 200 kcal per 100g:
8 × 4 ÷ 200 × 100 = 16% of energy from protein.
That clears the source threshold but falls below high protein. A second fictional food with the same 8g protein and 160 kcal gives 20%. It reaches the high protein threshold despite having no more protein per 100g.
The examples illustrate the arithmetic; rounded label figures can put a calculation close to a boundary. They are not enough to decide whether a manufacturer's claim meets every legal condition. The energy factor is set out in Annex XIV of the food information regulation.
What a smaller portion changes
If you eat 25g of the first fictional food, you get 2g protein and 50 kcal. Its protein share is still 16%. A smaller portion changes the amount you eat, not the ratio behind the claim.
Use our portion calculator to scale the protein grams to the amount on your plate. Compare the per 100g and per serving columns separately: one helps compare packets, the other helps understand a portion.
What the claim does not answer
High protein does not tell you whether a snack is low in sugar, salt or saturated fat, how much it costs, or whether you need additional protein. A prominent claim is one fact about the composition, not a score for the whole food.
A useful shop-floor routine is to check the protein grams per 100g, look at the amount you expect to eat, then read the rest of the nutrition panel and ingredients. Two products can meet the same claim and have quite different recipes.
Next, decode high fibre, whose thresholds use a different method.
Sources checked 21 September 2026. Examples are fictional; the calculations explain labels and do not certify a product or prescribe a diet.