Her first study found a rise in eating disorder symptoms among adolescent girls following the introduction of broadcast television to the island nation in 1995.

What makes Fiji a particularly interesting case is that traditional culture prizes a robust body shape, in sharp contrast to the image presented by Western television shows such as Beverly Hills 90210, Seinfeld and Melrose Place, which were quite popular in Fiji when television debuted there in the 1990s.

Girls would see actresses as role models, says Becker, and began noting how a slender body shape was often accompanied by success in those shows. This perception appears to have been one of the factors leading to a rise in eating pathology among the Fijian teenagers.

But until now, it was not known how much of this effect came from an individual's social network.

Nicholas Christakis, professor of medical sociology in the department of health care policy at Harvard Medical School, has studied the spread of health problems through social networks.

"It shouldn't be that surprising to us, even though it is intriguing, that the indirect effects of media are greater," Christakis said. "Most people aren't paying attention to the media, but they are paying attention to what their friends say about what's in the media. It's a kind of filtration process that takes place by virtue of our social networks."

Becker says that although the study focused on Fijian schoolgirls, remote from the US, it warrants concern and further investigation of the health impact on other populations.

Source: Harvard Medical School