Cage-free eggs at McDonald's, bans on suspect ingredients and "healthful" options edging out junk on supermarket shelves: could America be ready to end its decades-old love affair with processed food? US food firms and restaurant chains have been lining up to banish items perceived as unhealthy or unethical -- from additive-laden snacks to industrially-farmed meats -- in what experts see as a powerful trend. "It's kind of like a whole bunch of things happening, snowballing," said Penny Kris-Etherton, a professor of nutrition at Penn State University.