Forced Feeding

But Peeler said "a lot has changed" since 2005.

In November, the National Advertising Review Council launched the Children's Food and Beverage Advertising Initiative, a voluntary self-regulation effort that includes 11 of the largest food and beverage companies.

"This initiative is already designed to respond to" some of the problems the study found, Peeler said. "Participants pledge that a minimum of 50 percent of ads directed to kids under 12 will be devoted either to healthier products or healthier lifestyle messaging."

Ads will be monitored regularly to check on compliance, Peeler said.

Last month, the Robert Wood Johnson Foundation spearheaded formation of the Coalition for Healthy Children, a joint effort of the Ad Council, the American Heart Association and other groups that plans to use the popular characters from the animated movie Shrek to deliver healthier eating and physical activity messages to kids.

"This study is a wake-up call that we all must do more to address the impact of food advertising on children," Sen. Sam Brownback (R-Kan.) said in a statement. "On a daily basis, the average child in America is exposed to dozens of television advertisements for junk food."

But some said that even more needs to be done.

"We now have data that conclusively shows kids are seeing an overwhelming number of ads for unhealthy food on all types of TV shows," Sen. Tom Harkin (D-Iowa) said in a statement. "The 'childhood obesity epidemic' isn't just a catchphrase; it's a real public health crisis."

The latest statistics suggest that if rates of excess weight and obesity continue, today's children could be the first in generations to have shorter life expectancies than their parents. Weight-related illnesses once mostly limited to adults, such as Type 2 diabetes, high blood pressure, liver problems and premature heart disease, are already being diagnosed in children and teens.

"It's certainly up to parents to feed their kids a healthy diet," Wootan said. "But getting kids to eat a lot more healthfully would be a lot easier if parents didn't have to contend with $12 billion of junk-food advertising every year."