Most prepacked foods must carry nutrition labelling from 13 December 2016. Exemptions are mainly for minimally processed foods and those with little nutritional value. Nutrition information already being provided must be compliant from 13 December 2014. The EU FIC also includes rules on the provision on voluntary 'front of pack' nutrition information.

Derivation and accuracy of values

The declared values must be averages based on:

• Manufacturer's analysis of the food.
• Calculation from the known or actual values of the ingredients used.
• A calculation from generally established and accepted data.

The term 'average value' means a value that best represents the amount of the nutrient and allows for natural variability, seasonal variability, patterns of consumption and other factors that may cause the actual value to vary.

The nutrients and energy value must be for the food as sold. However, nutrition information may be given for the food after preparation if sufficiently detailed preparation instructions are provided.

The energy value must be calculated using conversion factors set out in the FIC, for example, one gram of fat will provide 37 kilojoules (kJ) and 9 kilocalories (kcal).

Tolerances and rounding

It is important that the actual nutrient content does not deviate substantially from labelled amounts. As a result, the European Commission has published guidance setting tolerances for declared nutrient values.

The measured value for nutrients should be within the tolerances for the declared value during the entire shelf life of the food. The tolerances set for the nutrition declaration on foods other than food supplements include the uncertainty of measurement associated with a measured value. The tolerances apply either side of the declared value. Separate tolerances are established for vitamins and minerals in foods by addition or in food supplements, and when nutrient levels are used to support claims.

Negligible amounts

The Commission guidance considers the amounts of nutrients that can be regarded as negligible and can be declared as '0' or '<x g' as follows:

Fat, carbohydrate, sugars, protein	≤0.5g per 100g/ml	"0g" or "<0.5g"
Saturates	≤0.1g per 100g/ml	"0g" or "<0.1g"
Salt	≤0.0125g per 100g/ml	"0g" or "<0"

Alternatively, where the energy or nutrient level is negligible, the information may be replaced by a statement such as 'Contains negligible amounts of...' in close proximity to the nutrition declaration.