Children are spending twice as much time in front of a TV or computer screen as in the classroom, according to a new book on how big business targets young consumers aggressively though new media.

It says that today's children are a captive audience for sophisticated and energetic marketing techniques because they spend so much of their day online or in front of the television.

In the U.S., children spend more time each year watching TV than they do attending school, which breaks down to 1,023 versus 900 hours, according to the Center for Screen-Time Awareness. On average, British children spend five hours and 18 minutes watching television, playing computer games or online each day. The total of 2,000 hours a year compares with 900 hours in class and 1,270 hours with their parents.

Consumer Kids, written by Ed Mayo and Agnes Nairn, warns of the dangers of relentless marketing to children through Web sites and other media, saying that it is an intrusion into their privacy and is destroying family life.

The book also reveals startling new data on the dominance of the media on children's lives, saying that it is hard for young people to escape from big business.

“The screen can no longer be classed as an electronic babysitter that keeps children occupied,” the book says.

“It is a whole electronic world in which they are immersed and which is underpinned firmly and securely by a profit motive. The conventional paradigm of childhood as a stage that evolves around family and schools has had to change. It's the commercial world that dominates the time of today's children.”

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