U. S. researchers said that children who spend more time watching TV and surfing the Web are more prone to health problems such as obesity and smoking. U. S. National Institutes of Health (NIH), Yale University and the California Pacific Medical Center experts reviewed 173 studies on media and health conducted over the past three decades to assess how exposure to media sources impacts the physical health of children and adolescents. The studies largely focused on television with some looking at video games, computer and internet, films and music. The researchers found that 80 % of the studies concluded that higher television and other media exposure resulted in detrimental health effects in children and adolescents. The relationship between media and obesity was examined by 73 studies and 86 % showed a link between media exposure and obesity.

The findings were released Tuesday by Common Sense Media, a nonprofit organization that seeks to improve the impact of media and entertainment on children and families. Lead researcher Dr. Ezekiel J. Emanuel, of the NIH said, "This review is the first-ever comprehensive evaluation of the many ways that media impacts children's physical health. The results clearly show that there is a strong correlation between media exposure and long-term negative health effects to children. This study provides an important jumping-off point for future research that should explore both the effects of traditional media content and that of digital media -- such as video games, the Internet, and cell phones -- which kids are using today with more frequency," Emanuel said.

The researchers recommend that parents limit their children's exposure to media and let them view only what they are ready for. They also felt there was a need for media literacy programs in schools with media literacy programs becoming a national priority.

"Media is increasingly pervasive in the lives of children and adolescents," said James P. Steyer, Common Sense Media founder and CEO. "Parents and educators must consider the effects of media when they're trying to address issues with their child's health. This report makes is clear that we need a bold new agenda on media and technology use. We hope this report will create a new sense of urgency in that regard."

Experts for decades have cautioned about the negative impact on young viewers of the violence and sexual content in some TV programs, movies and video games. They also feel the child is spending time sitting on a couch watching TV or playing computer games when they could be running around outside. "I think we were pretty surprised by how overwhelming the number of studies was that showed this negative health impact," said Emanuel. "The fact that it was probably more a matter of quantity than actual content is also a concern. We have a media-saturated life right now in the 21st century. And reducing the number of hours of exposure is going to be a big issue."

Dr. Cary Gross of Yale University School of Medicine in New Haven, Connecticut, another of the researchers said TV can negatively impact teens the most. He cited a U. S. study by the RAND research organization published in November that showed that adolescents who watched more programming with sexual themes had a higher risk of becoming pregnant or causing a pregnancy.