Manufacturers and retailers face a ban on describing their products as 'superfoods' under new laws coming into force later this year.

The EU's new nutrition and health claims regulation comes into effect on 1 July - after which time companies wanting to make a health claim on-pack will have to first prove it is true to the European Food Safety Authority.

This week one leading expert in the field warned that terms such as 'superfoods' and 'superfruits' could fall foul of the new rules because there is no hard and fast definition of what they really are.

"In terms of the new EU regulations, it could well become an issue that there is no official definition of a superfood," said Fiona Angus, nutrition business manager for Leatherhead Food International. "Some of the superfood claims lack clinical evidence. This means using the term as a way of branding a product may be at odds with the EU directive. There is no doubt going to be a huge number of questions as to how the regulations will apply to superfoods."

The news will come as a blow to suppliers such as Innocent, which markets a Superfood Smoothie range, and Jordans, which has a line of Superfoods cereals.

Retailers also use the terminology - M&S, for example, sells fruit packs with 'superfood' on them.

One nutrition expert said a clampdown on the use of the term was overdue. "The term is at best meaningless and at worst harmful," said Catherine Collins, chief dietician at St George's Hospital in London. "There are so many wrong ideas about superfoods that I don't know where best to begin to dismantle the whole concept."

The superfoods phenomenon began in the US 17 years ago with a book identifying a range of foods offering superior health benefits. Since then, the list of superfoods has continued to grow, with products credited with anything from boosting intelligence and libido to fighting cancer and improving heart health.