Research carried out by the independent watchdog the Food Commission found that so-called 'E-numbers' may adversely affect one in four toddlers.

The findings are based on reports from parents after their children consumed a drink that contained additives commonly found in popular crisps, sweets and fizzy drinks.

The evidence is quite sketchy

Nutrition Foundation spokeswoman

However, nutritionists have played down the findings saying they are not scientific.

Researchers from the UK's Asthma & Allergy Research Centre analysed the effects of five different additives on 277 three-year-olds from the Isle of Wight.

Common additives

These were the artificial food colourings tartrazine (E102), sunset yellow (E110), carmoisine (E122), and ponceau 4R (E124), and the preservative Sodium Benzoate (E211).

These additives were given to children in a single drink. The doses were similar to levels found in common foods.

According to the researchers, many parents reported significant changes in behaviour.

The Food Commission said that over 200 children's foods and drinks contained at least one of the additives used in the study.

"Nearly 40% of children's foods and drinks contain additives," said Annie Seeley, a nutritionist with the Food Commission.

"Colourings are used to make products look especially appealing to children. The colourings tested in this new research are used in familiar children's foods."

She suggested that the findings backed calls for these additives to be removed from children's foods and drinks.

Caution

But the British Nutrition Foundation said there was no evidence to support removing these additives from food.

A spokeswoman said: "The evidence is quite sketchy. There is a lot of anecdotal evidence but trials have been criticised in the past for being poorly designed and it is difficult to prove causation or association. It is difficult to define hyperactivity in children."

She added: "All additives go through rigorous testing in terms of safety so anything with an E-number means it has been approved for use in the UK and the EU and is safe."

But the spokeswoman suggested that parents who were concerned could choose alternative food or drinks that did not contain additives.

"There are lots of different products available. It is a question of choice for parents."