Fast-food chains have a New Year's resolution: drop the junk.

As people express distaste for food they think is overly processed, McDonald's, Taco Bell and other chains are trying to shed their reputation for serving reheated meals that are loaded with chemicals. That includes rethinking the use of artificial preservatives and other ingredients customers find objectionable.

"This demand for fresh and real is on the rise," says Greg Creed, CEO of Yum Brands, which owns Taco Bell, KFC and Pizza Hut.