What does high protein actually mean on a label?

Most people assume "high protein" is marketing language. It is not. In the UK, both "high protein" and "source of protein" are legally defined nutrition claims. A manufacturer cannot use them unless the product meets specific thresholds — and those thresholds are calculated from energy, not from weight.

The two thresholds

Source of protein means at least 12% of the product's energy comes from protein.

High protein means at least 20% of the product's energy comes from protein.

Those are the only two tiers. There is no "very high protein" or "ultra protein" with any legal meaning. If you see those phrases, they are marketing copy, not regulated claims.

Why energy, not weight?

It is a reasonable question. You might expect the rule to say something like "at least 20g of protein per 100g". It does not, and there is a practical reason for that.

Different foods have very different energy densities. A product that is 20g of protein per 100g of a dry powder is not comparable to 20g of protein per 100g of a high-fat nut butter. Anchoring the threshold to energy — specifically, the proportion of total calories that come from protein — makes the comparison consistent across food types.

Protein provides 4 kilocalories per gram. Fat provides 9. So a product can have a reasonable amount of protein by weight and still fail the 20% energy threshold if it is also high in fat or carbohydrate. The energy basis is stricter than it first appears.

What this means for our products

Both products below meet the high protein threshold — well above the 20% of energy mark — which is why we can state the following authorised claims for them:

Protein contributes to a growth in muscle mass.
Protein contributes to the maintenance of muscle mass.
Protein contributes to the maintenance of normal bones.

These claims apply to any product that is at least a source of protein (12% of energy). The conditions of use are set out in the table below.

Authorised protein claims and conditions of use
Authorised claim	Minimum product requirement
Protein contributes to a growth in muscle mass.	At least a source of protein: 12% of energy from protein.
Protein contributes to the maintenance of muscle mass.	At least a source of protein: 12% of energy from protein.
Protein contributes to the maintenance of normal bones.	At least a source of protein: 12% of energy from protein.

Our Whey Protein Concentrate 80 is unflavoured, mixes into water, milk or a shake, and contains sunflower lecithin for consistent dispersal. One scoop is a straightforward post-training or between-meals serving.

Our Faba Bean Protein Isolate is a plant-based alternative with a neutral flavour — it does not carry the earthy aftertaste common in pea protein. Two scoops (around 30g) per serving, from a 1kg bag that gives approximately 33 servings. It is thicker than whey, so use at least 200ml of liquid, or a blender. It also holds texture in baking where whey tends to go rubbery.

How we write our labels — why our descriptions are more restrained than most.

Why protein bars and cereals often scrape the threshold

A 20g protein bar that also contains 30g of sugar and 10g of fat has a lot of energy coming from sources that are not protein. Run the numbers and it may only just clear the 12% source-of-protein threshold, or fail to reach it at all. That is why some bars carry the claim and some, despite appearing similar, do not.

Cereals face the same issue. A breakfast cereal fortified with protein can still have most of its calories coming from carbohydrate. "High protein" on a cereal box means the manufacturer has done the energy calculation and passed. "Protein-enriched" or "with added protein" has no legal definition and tells you nothing about the actual proportion.

The short version: look at the nutrition panel, find the energy per 100g in kilocalories, multiply the grams of protein by 4, and divide. If that figure is below 12%, the product is not legally a source of protein regardless of what the front of pack says.