In Europe the demand of functional foods varies remarkably from country to country, on the basis of the alimentary traditions, the enforced legislation and the different cultural heritage that people have acquired. The opportunities of expansion on the market seem to be quite favorable and the interest of the consumers is rather high. But the diffusion of these products in the community area is slowed down by some obstacles. One of main ones is the lack of an official law-recognized definition for these references, necessary in order to clearly assign these products to the food sector rather than to the pharmaceutical one. In a such situation, we note that nowadays it is impossible to carry out a complete survey of this world, due to the lack of homogeneous and trustworthy statistical data and to the confused definition of the sector. In fact, every country adopts his own national legislation and includes in this class different products. The variable meaning assumed by the term "functional food" in the EU member states, can also hinder the free trade even within the EU boundaries. In fact, pursuing the safeguard of human health, each partner can block the admission of a product, even if it comes from an other EU member country. This lack of clarity at the production phase is reflected in a difficult control at the consumption phase. The disinformation of the trade operators and, consequently, of the consumers can involve some risks for these last ones due to not only to the deficiency of benefits, using functional foods, but also possible damages to the health. Ambiguous definition and gaps of knowledge about the composition and the effects of these products, in fact, can interfere with an aware choice of purchase and an organized development of the sector.