For Helen Buniak, today’s report represents belated vindication of a long-held belief: that colourings and preservatives play a crucial role in her son Lee’s hyperactive behaviour.

“It has been terrible,” she said. “Just last week I got a letter from the hospital saying they don’t think his problems are linked to food.

“The primary care trust won’t fund him to see a specialist and another doctor suggested the issue might be that he has a phobia of ice cream and sweets. Have you ever heard of a child like that?”

The former social worker is adamant that preservatives and additives have a profound effect on the ten-year-old. “I am house-bound when he has eaten them,” she said. “My 15-year-old daughter is unaffected, but with Lee, it’s like Jekyll and Hyde.

“When he was younger, I used to give him brightly coloured party food at family events, and would always have to leave early. Now he is bigger, I can’t control his hyperactivity and aggression outside the house when he has eaten these things so we simply have to stay in.”

Ms Buniak, from Waltham Forest, East London, first noticed the link 2½ years ago, when five birthdays within ten days in Lee’s school class meant lots of sweets and, as a result, five “explosive incidents”.

“Since then, I have completely changed his diet, cutting out all additives. Within a few days, I really noticed a change. The biggest shock was the improvement in his learning.”

Nick Giovannelli, who helps to run workshops for the Hyperactive Children’s Support Group in London, tells a similar story: “My son was permanently excluded from school at the age of 6. At his second school, the problems continued. Then we changed his diet, and when he went back after the holidays the teachers assumed he was on drug therapy.”

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