What the table must contain
Under the food information rules that apply in Great Britain, the mandatory nutrition declaration consists of energy value and the amounts of fat, saturates, carbohydrate, sugars, protein and salt. The order is prescribed, which is why every compliant table on every pack reads in the same sequence.
Energy is given in both kilojoules and kilocalories. The nutrients are given in grams. Salt is expressed as salt rather than as sodium, which was a deliberate change intended to make the figure directly usable by shoppers rather than requiring a conversion.
Additional nutrients may be declared voluntarily, from a defined list, and where they are declared they must be presented in the prescribed order and format. The table is therefore not a free-form panel. Its shape is set by the rules, and a producer choosing to add a row is choosing from a list rather than inventing one.
Per 100g is the load-bearing column
The declaration must be expressed per 100g or per 100ml. That single requirement is what makes the table a comparison instrument.
A per portion column may be given in addition, and very often is. It is useful for a different question, which is what a serving contributes. It is close to useless for comparing two products, because the portion size is chosen by the manufacturer within general rules, and two comparable products can declare quite different portions.
The disciplined habit is therefore simple: for comparison, use per 100g and ignore everything else; for the contribution of a serving, use the per portion column and check what portion size it assumes, which must be stated.
Where a food needs preparation, the declaration may relate to the food as sold or, where sufficient detail is given, as prepared. Which basis is in use has to be stated, and it is worth checking before comparing two products that may not be declared on the same basis.
| Row | Unit | Note |
|---|---|---|
| Energy | kJ and kcal | Both units are required |
| Fat | g | |
| of which saturates | g | Indented under fat |
| Carbohydrate | g | |
| of which sugars | g | Indented under carbohydrate |
| Protein | g | |
| Salt | g | Expressed as salt, not as sodium |
Structure set out by this newsroom from the published rules named in the sources below. It is not a survey, a measurement or a market study.
Reference intakes, and what they are not
Many tables carry a percentage figure alongside the nutrient amounts, referring to a reference intake. The reference intake is a defined benchmark used for labelling purposes, based on a notional adult, and it exists so that a number on a pack has a scale attached to it.
Two misreadings are common. The first is treating the reference intake as a recommendation for the individual reading the label. It is not personalised, it takes no account of age, size, activity or any medical circumstance, and it is not dietary advice. The second is treating a percentage as a verdict, when it is simply the nutrient amount expressed against a fixed denominator.
Where reference intake percentages appear on the front of a pack, additional rules apply to how they may be presented. The government publishes guidance on front-of-pack nutrition labelling that covers the permitted formats.
How the numbers are arrived at
Declared values are averages. Food information law is explicit that the values are average values based on the manufacturer's analysis of the food, on a calculation from known or actual average values of the ingredients used, or on generally established and accepted data.
That is a more permissive basis than many readers assume, and it is a sensible one. Natural variation in agricultural ingredients means that a single analytical result would not be representative, and requiring batch-by-batch analysis of every product would be disproportionate. Tolerances are addressed in guidance, because a declared average has to be workable against a real distribution of results.
The practical implication is that small differences between two products are not meaningful. A gap of a fraction of a gram per 100g between two similar items sits comfortably inside the variation the system is designed to accommodate. Large differences are real. Small ones are noise.
Where there is no table at all
Not every food carries a nutrition declaration. There are defined exemptions in the rules, covering categories such as unprocessed single-ingredient products, certain waters, herbs and spices, and food supplied in small quantities directly by the producer, among others.
Alcoholic drinks above a defined strength are treated separately, and the labelling requirements for them differ from those for foods generally. Where a food is not prepacked, the obligations are different again, and any nutrition information provided is generally voluntary and subject to its own rules once given.
An absent table is therefore not a gap in compliance. It usually means the product falls into an exempt category, and the correct inference is about the category rather than about the producer.
Using the table well
Three habits make the table considerably more useful without requiring any nutritional expertise.
Compare within a category, never across one. The table answers the question of how two similar products differ. It answers nothing useful about how a product from one category compares with one from another, because they are eaten in different quantities and for different reasons.
Read the salt row as salt. Because the declaration is expressed as salt rather than sodium, the figure is directly usable without a conversion. Older references and imported packaging conventions can express sodium instead, and the two are not interchangeable.
Check the basis before comparing. As sold or as prepared, and per 100g or per portion, are the two axes on which comparisons quietly go wrong.
The line this publication does not cross
This article describes what a table contains, how it is derived and how to compare two of them. It does not tell you what to eat, what any figure means for your health, or what a reasonable intake is for you.
Those are clinical and dietary questions, and they belong with a professional who knows your circumstances. The NHS publishes general guidance on food labels and on diet, and a registered dietitian is the right route for anything specific. A pack is a declaration of composition. It is not a plan.
Elsewhere on Feedworthy. Why online recipes are written the way they are. Promotion and advertising restrictions on certain foods: what the rules do. Green claims on food: the code, the Act and what changed.