Childhood is being poisoned by a dangerous combination of junk food, marketing and video games, experts warned today.

A group of 110 eminent teachers, psychologists, children’s authors and other experts have written to a newspaper urging the Government to act, warning that the demands and restrictions of the modern world are denying children the opportunity to grow up at their own pace.

The group includes Jacqueline Wilson, the children’s laureate, Philip Pullman, a celebrated writer, Baroness Susan Greenfield, the director of the Royal Institution and Dr Penelope Leach, a child care expert.

They write: "We are deeply concerned at the escalating incidence of childhood depression and children’s behavioural and developmental conditions.

"Since children’s brains are still developing, they cannot adjust as full-grown adults can, to the effects of ever more rapid technological and cultural change.

"They need what developing human beings have always needed, including real food (as opposed to processed "junk"), real play (as opposed to sedentary, screen based entertainment), first hand experience of the world they live in and regular interaction with the real-life significant adults in their lives.

"They also need time. In a fast-moving, hyper-competitive culture, today’s children are expected to cope with an ever-earlier start to formal schoolwork and an overly academic test-driven primary curriculum."

It concludes by calling for a public debate on child-rearing in the 21st century.

The letter to the Daily Telegraph was circulated by Sue Palmer, a former head teacher and author of the book Toxic Childhood, and Dr Richard House, senior lecturer at the Research Centre for Therapeutic Education at Roehampton University.

Mrs Palmer cited research by Professor Michael Shayer at King’s College, London, which showed that 11-year-olds measured in cognitive tests were "on average between two and three years behind where they were 15 years ago".

She said: "It is like this giant elephant in all our living rooms, the fact that children’s development is being drastically affected by the kind of world they are brought up in.

"I think it is shocking. We must make a public statement - a child’s physical and psychological growth cannot be accelerated. Childhood is not a race."

Other signatories include environmental campaigner Sir Jonathon Porritt, Professor Tim Brighouse, the Commissioner for London Schools, and Sir Richard Bowlby, President of the Centre for Child Mental Health.

Explore UK News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• Alex Rider exclusive: Incident in Nice
• Green & confused: do energy-saving bulbs work?
• Let’s skip lunch, say the hungry generation