But there's a newer, growing worry. It's how certain forms of advertising exploits young girls' sense of self-esteem, and its ties to sexual imagery are quite direct.

It's a complaint similar to those long leveled against magazines aimed a teen girls and young women, that they prey on their sense of inadequacy about their bodies and their sexuality to sell magazines and, by extension, the products of their advertisers.

This growing concern underlies a recent British study that set out to synthesize research on the effects of the commercialization of childhood.

Among them is a serious psychological impact that comes from bombarding children with messages about not just what they should own, what toys to have, but how they should look, the perfect body images portrayed as cool, especially to little girls.

These marketing messages, argues the report, by Compass, a left-leaning think tank, are contributing to children's feelings of being unable to keep up, as well as to stress and anxiety. Among boys, it cites record levels of mental health problems, along with bullying and fighting.

Among girls, it contends the slim, leggy, clear-complexioned women portrayed favorably by marketers are leading to lower self-esteem.

“I think for us the thing that came out of the research that we did was the vast scope and intensity of marketing to children,” says Zoe Williams, campaigns officer at Compass.

“Our concern is the effect it is having on children’s physical and mental health and how it is affecting their aspirations,” she says. “Children are more interested in having the right gear than in wanting to do something a bit more productive.”

At the heart of much marketing is the concept of cool. “Marketers play on children’s fears of not fitting in by promoting images of how they should be and what they should own,” the report finds.

Female singers such as Britney Spears and Christina Aguilera are marketed to kids yet are tricked out to look like quintessential male fantasies of teenybopper hookers, all the while singing songs about sex written, the report notes, by middle-aged men.

When it comes to toys, there are the Bratz dolls, which are popular with kids as young as 6. One set of Bratz dolls is sold with two Bratz boys, champagne glasses and, the report notes, “tons of date night accessories.”

“Girls in particular experience feelings of inadequacy and discomfort as a result of ‘images of perfection’ promoted by advertising,” says the report, citing findings from National Consumer Council research.

The idea behind the Compass report, its authors say, is to stimulate debate, but in Europe that's hardly an issue. It's a debate that never ends and hardly ever stops for a breather, as reformers demand ever tighter controls on advertising to children. In Sweden all children's advertising is banned, and in the UK junk food messages are restricted.

“There are lots of questions around marketing and lots of strong opinions,” says Tim Linehan, spokesperson for Britain's Children’s Society, which has endorsed the Compass report and has launched its own study. The issue, Linehan says, is the best way to curtail the abuses.