You eat a lot of cheeseburgers at fast-food restaurants and you get fat.

But whose fault is that?

Lawyers for two obese teenagers in New York say McDonald's is to blame, and they're taking Ronald to court.

Kids just can't resist those happy meals, says one adviser on the case.

"When we're suing on behalf of children, it's hard to argue that a 6, or 8 or 10-year-old child has to take full responsibility for their decisions when they're lured into McDonald's by the toys and the playground and happy meals and the birthday parties," said attorney John Banzhaf.

The lead attorney in the most recent case, who also represents adults in a similar suit, refused to talk to Fox News on camera about the case. Nor would he let Fox News talk to the parents or his teenage plaintiffs.

But what is known is that both of his latest obese plaintiffs are girls. One is 5'9" and weighs 270 pounds, while the other is about 5'3" and 200 pounds.

Each girl is at least 80 pounds overweight, according to government statistics.

They have been eating at McDonald's several times a week for years.

Fox News broke a similar story this summer, when an obese man blamed his fatness and health problems on the food served up at Burger King, McDonald's, Wendy's and Kentucky Fried Chicken.

McDonald's says the average person eats there only twice a month and that this lawsuit has no merit.

The burger joint says it handles nutrition responsibly. It puts nutritional information about its products on large, poster-size charts on its store walls and in other display areas.

The charts show, for instance, that a quarter pounder with cheese has 530 calories and 30 grams of fat.

Nevertheless, the lawsuit claims kids and their parents didn't know how fattening the food was.

One restaurant group says that's ridiculous.

"You make choices in the food you want to purchase, and if you make the wrong choices relentlessly and perpetually, you're going to have health consequences," said John Doyle, co-founder of the Center for Consumer Freedom, a coalition of restaurant operators and individuals. "But that is not something that the restaurants are responsible for."

Critics say this class-action lawsuit reminds them of the lawsuit against Big Tobacco, in which lawyers blamed wealthy corporations for the personal choices of others.

Some legal observers are asking what the next target is -- pizza or ice cream?