UN calls for limits on junk food ads for kids

She added that food marketing is commonly present in places where children should be "protected, such as schools and sports facilities."

The WHO has reported that on average, one in three children between the ages of 6 and 9 is overweight or obese.

Obesity among U.S. kids has more than doubled in the past three decades, according to the Centers for Disease Control and Prevention, and health advocates see growing waistlines as an unfolding crisis.

The Obama administration has sought to crack down on school-based sales of unhealthy snacks and promote fitness through first lady Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama criticizes lack of diversity in politics: one side is 'all white, all men' Obama interrupts Michelle's appearance with 25th anniversary tribute Michelle Obama: Young people feel what's happening now 'not what they were taught' MORE's "Let's Move!" campaign.

The Walt Disney Co. has also partnered with Obama to implement nutrition standards for the foods it markets to younger viewers.

The American Academy of Pediatrics and others have urged Nickelodeon to make a similar pledge. The network says it's been on the cutting edge of fighting childhood obesity through positive advertising.

WHO Europe said in a report that food ads are effective with kids because, as an audience, they can't distinguish between marketing and cartoons.