Food products intended for a special diet -DIETETIC- are those which, by their nature or manufacturing process are appropriate to fulfil the particular nutritional aim for which they are intended, and must be sold stating that the fulfil such an aim (Royal Decree 1809/1991 13 December 1991, amending the Technical and Health Regulation on production, distribution and sale of preparations for dietetic or special regimes, approved by Royal Decree 2685/1976).

As for substances which can be added for specific nutritional purposes in producing foodstuffs intended for special diets included in Directive 2009/39/CE, only those can be used, if necessary, that appear in the annex of Commission Regulation (EC) 953/2009 of 13 October 2009 on substances that may be added for specific nutritional purposes in foods for particular nutritional uses, that comply with the relevant specifications. This regulation does not apply to food based on cereals, baby and infant food, nor to preparations for newborns and later feeding, as these are regulated by their own list of substances in specific legislation.

Specific legislation to regulate, among other, composition and labelling requirements, has been drawn up for certain categories of dietary food.