Donald Zeigler, director of Prevention and Health Lifestyles at the American Medical Association, was there. He asked when the burger chain will stop marketing to children using Ronald McDonald. Zeigler was one of 550 healthcare professionals who had signed an open letter to McDonald's pleading that it "stop making the next generation sick." And on Tuesday, a watchdog group placed ads in newspapers across the country calling for McDonald's to stop marketing to children through the clown, toy giveaways and other tactics. Skinner said Ronald McDonald will stay central to efforts to promote products like Happy Meals.