Rich diet of jargon is recipe for confusion

A study by the Which? consumer group found that 33 per cent of consumers thought the phrase "real fruit" meant fruit was the main ingredient of a product, while 43 per cent believed that products labelled "juice drink" must contain at least a quarter fruit juice.

The terms "fruit juice" and "fruit juice from concentrate" are subject to European legislation, but the phrase "juice drink" is not.

The watchdog found that Rubicon Sparkling Passion was legally entitled to include the words "real fruit juice drink" on its label, despite having just 5 per cent juice concentrate and more sugar than concentrate.

The watchdog also looked at Heinz Farmers' Market products, saying: "While the image of these mass-produced soups flies in the face of what we understand by farmers' markets, legally there's nothing to stop Heinz using the term."

Which? also highlighted the "confusing" difference between the terms "flavour" and "flavoured", pointing out that Yop Strawberry Flavour Drinking Yoghurt does not contain strawberries. The Department for Environment, Food and Rural Affairs considers "flavour" to relate to artificial flavouring and "flavoured" to mean natural ingredients.

European food law says "the labelling and presentation of food should not mislead consumers", while the UK's Food Standards Agency publishes guidance on the use of particular words and phrases commonly used to describe food but it is not legally binding. However, terms including "organic" and "free range" are strictly governed to guarantee factors such as welfare standards and the use of pesticides and fertilisers.

Dr Jeff Brunstrom, a reader in behavioural nutrition at the University of Bristol, said: "While phrases and labelling affect consumer behaviour and purchases, it may also impact on how people consume. Studies indicate that people may feel less full and therefore eat more of a product if it's described as 'light'."