In this file photo taken May 18, 2006, Ronald McDonald visits with children at a McDonald's Restaurant in Roswell, N.M. Some branding experts think the McDonald’s Corp. clowns’ floppy red shoes and flaming-red hair are too hackneyed for iPod-savvy kids. – AP Photo

NEW YORK: Hundreds of health organizations and professionals signed a letter to McDonald's Corp asking the fast-food chain to stop marketing junk food to children.

The letter, organized by watchdog group Corporate Accountability International, is slated to run in full-page advertisements in six newspapers -- in Boston, Chicago, New York, San Francisco, Minneapolis and Baltimore -- on Wednesday, a day ahead of McDonald's annual shareholders' meeting.

It cites concerns about the health of US children, ballooning health care costs and an overburdened health care system.

“We ask that you heed our concern and retire your marketing promotions for food high in salt, fat, sugar and calories to children, whatever form they take -- from Ronald McDonald to toy giveaways,” said the letter.

The letter was signed by more than 550 health professionals and institutions from the American Academy of Child and Adolescent Psychiatry to Marion Nestle, a professor at New York University's Department of Nutrition, Food Studies and Public Health and the author of several books.

McDonald's was not immediately available for comment.