The Food Information Regulation ("FIR") establishes the rules for the (basic) labelling of food in the European Union. A nutrition declaration, among other things, is mandatory. It must show the energy values and amounts of nutrients in addition to other information. The energy values and amounts of nutrients are those of the food at the time the product is sold to the consumer. However, the information may also relate to the food after preparation, "provided that sufficiently detailed preparation instructions are given and the information relates to the food as prepared for consumption" (Article 31(3) Food Information Regulation).
The energy values and amounts of nutrients in a food product can vary depending on how it is prepared. The original case concerned muesli, on the front of the packaging of which certain energy values and amounts of nutrients were stated, based on a 40g serving of the muesli prepared using 60ml of milk with a fat content of 1.5%, which the German Federal Union of Consumer Organisations and Associations described as being a "cosmetic use of the figures". The German court hearing the case requested a preliminary ruling from the CJEU concerning the interpretation of Article 31(3) of the Food Information Regulation.
In its decision of 11 November 2021 (Dr. Oetker, C-388/20), the ECJ stated that Article 31(3) of the Food Information Regulation only applies to foods requiring preparation where the method of preparation is specified. On the other hand, if a food can be prepared in various ways (such as in the case of muesli by adding milk, yoghurt, juices, etc.), the consumer is only able to compare products and information based on the energy values and amounts of nutrients indicated at the time of sale.