reporter: the center for science and the public interest, a see-called food police is backing monet parham'ssuit. >> they dangle the little toys in front of little kids to get them to pester their parents to take them to mcdonald's. it's a trick that works. >> reporter: they've done this before. five years ago they sued kellogg's or forced them to stop advertising suingry cereal. ♪ fruit flavors >> reporter: to kids during saturday morning cartoons. the case never got to court. instead they agreed to stop advertising to kids with any products with more than 200 calories per serving. csci says in both cases the problem isn't just the way the companies market their food, but the food it sells. >> the happy meals range from mediocre to junkie. they're oftentimes high in calories, high in fat. high in salt. you know, exactly what the surgeon general has said don't eat. >> reporter: american children are among the fattest in the world. one in three are considered overweight or obese. >> childhood obesity is a big problem and when you look at past issues such as people having to wear seat belts as

parham find them irresistible. >> well, this one, it has a mirror. >> reporter: but mya's mom monet says those toys draw her kidsknow, there's these toys, they come with the happy meals. we have eight of them. so even for my 6-year-old, the question is, well, can we go every week until we get them all, mom? of course my answer is no. that's when the battle ensues. can you read that to me? >> reporter: so she's suing mcdonald's. her ultimatum to the golden arches, make the meals healthier or stop including the toys. monet is the first mother to take this kind of drastic action, but her efforts are part of a larger movement. the city of san francisco recently passed a law requiring meals with toys to meet certain nutritional standards effectively banning happy meals. the center for science and the public interest, the so-called food police, is backing monet's lawsuit. >> they dangle these little toys in front of little kids to get them to pester their parents to take them to mcdonald's. it's a trick that works. >> reporter: mcdonald's says the lawsuit may make for good headlines but not common sense. >> taking awa