NEW YORK - McDonald's, which is trying to shake its image for serving processed junk food, said Monday it's eliminating some unpalatable ingredients from its most popular menu items.

That includes making Chicken McNuggets and other items without artificial preservatives, and removing high-fructose corn syrup from its burger buns. McDonald's did not immediately respond when asked about which specific preservatives are being removed.The changes come as the world's biggest burger chain fights to win back customers after three straight years of declining guest counts at its established U.S. locations. Major restaurant chains are scrambling to step up the image of their food as they face more competition from smaller rivals promising wholesome alternatives."Why go to the position of trying to defend them, if the consumer is saying, I prefer not to have that particular ingredient in my food?" said Mike Andres, president of McDonald's U.S., during an event at the company's headquarters in Oak Brook, Illinois, about its "food journey."How meaningful the changes are to customers remains to be seen.Michael Jacobson, executive director for the Center for Science in the Public Interest, said the moves by McDonald's don't seem to address the big-picture problem with restaurant food - the overabundance of calories.