reports that five hundred and fifty doctors have sent an open letter to McDonald's, telling them they are encouraging obesity, and that Happy Meals get children addicted to junk food.
The campaign group Corporate Accountability International took out full-page adverts in US newspapers with the letter, which was addressed to the firm's headquarters.
The letter read: "Marketing can no longer be ignored as a significant part of this huge problem".
It then went on to demand that McDonald's stops aiming their high fat, high salt and high sugar foods at kids.
reports that the restaurant's longtime mascot Ronald McDonald is also at risk.
Many parents believe that the clown is not a good role model for the children of today.
"Stop making the next generation sick - retire Ronald and the rest of your junk food marketing to kids," said Dr. Steven Rothschild, an associate professor of preventative medicine at Rush Medical College.
However, the firm has no intention of retiring either Ronald McDonald or
the Happy Meal.
A spokesperson for the franchise has said: "Ronald McDonald has never left McDonald's. He has been our mascot for 35 years. We serve high quality food. Our Happy Meals offer choice and variety in portions for kids."