Front-of-pack nutrition claims: the legal thresholds

On a UK food pack, no added sugar, reduced sugar, light, source of fibre and high in protein are regulated nutrition claims, not general impressions. Each has a stated threshold or test. Check the exact claim, the nutrition declaration, any comparison product and the qualifying wording before treating the front label as proved.

The short rule: read the claim as a test

Front-of-pack nutrition claims are not simply product descriptions. Where a pack says no added sugar, reduced sugar, light, source of fibre or high in protein, the wording falls within rules on nutrition claims. The claim must meet the applicable condition in the retained nutrition and health claims framework and must not mislead the purchaser.

The most useful reading order is not to start with the picture, flavour name or large type. First identify the exact claim words. Then turn to the nutrition declaration and, where the claim compares the product with another food, find the comparison explanation. Finally, look for mandatory accompanying wording. A claim may be legally possible while still answering a narrower question than a shopper assumes. “High in protein”, for example, is a test about the share of energy supplied by protein. It is not a statement about ingredients, processing, suitability for a particular person or the role of protein in a diet.

Claims may appear on the front, side, back, a label attached to a multipack or other presentation associated with the food. Their position does not alter the condition. A large front-of-pack phrase still has to be supportable by the food as sold, using the relevant calculation basis.

These rules concern the words used to sell the food. They are distinct from voluntary front-of-pack nutrition labelling such as traffic-light colour coding, and distinct from health claims that link a nutrient to a bodily function. Do not use a nutrition claim’s threshold as a general measure of nutritional quality.

A screenshot rule for checking the five claim types

Use the table as a document check. It states the legal condition most directly relevant to each phrase. “Per 100 g” applies to foods generally; drinks are normally assessed per 100 ml in the nutrition declaration, but the fibre conditions are expressed by the legal alternatives shown below. Percentage of energy is not the same thing as percentage by weight.

Decision rule: if the pack does not show enough information to perform the relevant check, do not fill the gap with an assumption. For comparative claims, the missing fact is often the comparator. For “no added sugar”, it is often whether naturally occurring sugars are declared as such. For protein, it is usually necessary to calculate energy rather than compare the grams figure alone.

What “no added sugar” permits, and what it does not say

A food may carry a “no added sugars” claim only if it has not had monosaccharides or disaccharides added to it and has not had any food added for its sweetening properties. Monosaccharides and disaccharides include familiar sugars such as glucose, fructose and sucrose. The rule is not limited to an ingredient literally labelled “sugar”. Adding another food in order to sweeten the product can also prevent use of the claim.

The claim does not mean that the food contains no sugar. Fruit, milk and other ingredients can contain sugars that occur naturally. Where a food making the claim contains naturally occurring sugars, the label must also state that it contains naturally occurring sugars. This accompanying statement is a key part of the claim’s legal meaning, not optional explanatory decoration.

A practical check starts with the ingredients list. Look for sugars and ingredients that appear to have been used to sweeten. Then read the carbohydrates line in the nutrition declaration, especially the “of which sugars” figure. That figure records sugars in the food; it does not, by itself, establish whether sugar was added. The ingredients list and the qualifying statement do that different work.

Do not translate “no added sugar” into “sugar-free”. Sugar-free is a separate regulated claim with its own condition. Nor does “no added sugar” prove that a product is unsweetened in an everyday sense. The legal issue is the addition of specified sugars or a food used for sweetening, alongside the required clarification where natural sugars are present.

Reduced sugar: a comparative claim needs a real comparator

“Reduced sugar” is a form of “reduced [name of nutrient]” claim. It is permitted only where the reduction in the content of the named nutrient is at least 30% compared with a similar food. For a reduced sugar claim, that means the sugar content must be at least 30% lower than the comparable food’s sugar content.

The comparison cannot be invented by the reader. It must be against a similar food, and the claim must state the characteristic or characteristics that make the food reduced. In practice, a shopper should look for wording that identifies what comparison is being made or explains the basis on which the product differs. A vague impression that the product seems less sweet, comes in a smaller portion, or has fewer calories is not the legal test for reduced sugar.

The nutrition declaration can help test plausibility but may not settle the question alone. If the current pack shows 8 g sugars per 100 g, a reader still needs a valid similar comparator to know whether the required 30% reduction has been achieved. Comparing it with an unrelated product, a different flavour, or an arbitrarily selected market item may not answer the regulatory question.

The claim concerns sugar content, not necessarily energy value. A formula can change in ways that affect energy, fat, fibre or ingredients while the legal claim remains specifically about the required reduction in sugar. Read the named nutrient literally and seek the comparison detail before drawing a broader conclusion.

When “light” or “lite” is allowed

“Light” and “lite” are regulated nutrition claims when used in relation to a food’s nutritional content. They are not free-standing synonyms for small, delicate or easy to eat where their presentation is likely to communicate a nutritional advantage. The legal condition is that the food meets the conditions for a “reduced” claim, and the claim must be accompanied by an indication of the characteristic or characteristics that make the food light or lite.

That makes “light” a comparative term. It needs a reduction meeting the relevant reduced-claim condition, rather than merely a lower number than a shopper expects. Where the characteristic is sugar, the required reduction is at least 30% compared with a similar food. Other characteristics may involve a different named nutrient or energy, but the pack should indicate which characteristic is doing the work.

Check the words immediately beside or close to “light” or “lite”, then check the nutrition declaration. If the front says “light” but does not make clear whether this refers to sugar, fat, energy or another characteristic, the shopper has a reason to look for a fuller explanation elsewhere on the pack. A product name can create a different interpretative question, but visual prominence and context matter when deciding whether consumers are being presented with a nutrition claim.

“Light” is not a legally defined overall grade for a food. It does not itself establish a particular calorie figure, serving size, ingredient standard or health outcome. Its required meaning is tied to a qualifying reduction and to disclosure of what has been reduced.

Source of fibre: check the amount, then the basis

A “source of fibre” claim is allowed where the food contains at least 3 g of fibre per 100 g, or at least 1.5 g of fibre per 100 kcal. Either route can satisfy the condition. The alternative matters because a food’s fibre content can be expressed against its weight or against its energy value.

First locate the nutrition declaration and find the fibre figure. Then note whether the label gives values per 100 g, per 100 ml, per portion, or more than one of these. A per-portion figure can be useful context, but it does not replace the legal threshold as written. Where the claim is being assessed on the energy basis, the calculation needs the food’s energy value as well as its fibre amount.

Do not substitute a different phrase. “Contains fibre”, “with fibre” and “source of fibre” may create different questions depending on their wording and presentation. The regulated phrase in this article is “source of fibre”, whose specified threshold is the one above. “High fibre” is a separate stronger claim: it requires at least 6 g of fibre per 100 g or at least 3 g of fibre per 100 kcal.

Ingredient references such as wholegrain cereals, seeds, pulses or vegetables do not automatically prove a source-of-fibre claim. The legal test is the fibre content of the food under the stated calculation routes. Equally, a pack’s fibre number is not a direction about how much of the product a person should eat. It is evidence relevant to one tightly defined labelling claim.

High in protein: calculate protein’s share of energy

“High protein” or “high in protein” is permitted only where at least 20% of the energy value of the food is provided by protein. This is an energy-share test. It is not a simple requirement to reach a particular number of grams of protein per 100 g, per 100 ml or per serving.

For a pack check, take the protein quantity and energy value from the nutrition declaration on the same basis, normally per 100 g or per 100 ml. Protein provides 4 kilocalories per gram. Multiply the listed protein grams by 4, divide that result by the listed kilocalories, then multiply by 100. The result is the percentage of energy supplied by protein. The claim needs a result of 20% or more.

For example, if a food lists 10 g protein and 180 kcal per 100 g, protein supplies 40 kcal. Forty divided by 180 is about 22%. On those figures, the energy-share test is met. This arithmetic does not assess the food in any wider way; it simply tests the condition for the claim.

“Source of protein” is the lower related claim. It requires protein to provide at least 12% of the energy value of the food. The difference illustrates why grams alone can mislead: two foods can list the same protein grams while having substantially different total energy values. Check that the figures use the same declared basis and avoid mixing a portion protein figure with a per-100 g energy figure.

Limits, enforcement and what this guide does not cover

This guide addresses five nutrition claims on food packaging sold in the United Kingdom and the practical reading of their core conditions. It does not decide whether a particular pack is compliant. That can depend on the full label, recipe, product category, presentation, substantiation and the law applicable in the relevant part of the UK. Northern Ireland operates within a different legal context for some food rules, so a Great Britain-focused reading should not be treated as a complete Northern Ireland compliance assessment.

It does not cover health claims, medicinal claims, nutrition advice, allergens, date marks, origin declarations, organic certification, environmental claims or advertising outside the pack. Nor does it assess whether protein, fibre or sugar has a beneficial or harmful effect for a particular person. Those are questions beyond claims and labelling law.

Food labelling requirements are generally enforced through local authorities. An authority can consider the label as a whole, including whether presentation is misleading, rather than looking only at a single number in isolation. The Food Standards Agency provides public information on food labelling and food businesses, but it is not a substitute for an authority’s assessment of an individual product.

For shoppers, preserve the evidence: photograph the complete front and back, including the ingredients list, nutrition declaration, comparison wording and qualifying statements. For businesses, a formula calculation is only one part of compliance. Keep the evidence for the claim, confirm that the final label uses the permitted wording and accompanying statements, and obtain specialist regulatory advice where the claim or comparator is uncertain.