Taco Bell and Pizza Hut announced they are phasing out artificial flavors and colors.  McDonald's is phasing out use of human antibiotics in chicken, and Subway has promised to remove an ingredient dubbed the "yoga mat chemical" from its bread. Why are all these changes happening at once, and what do they mean for us?

Mark Brandau, author of Technomic's recent white paper, "Food Industry Transformation: The Next Decade," told us, "You can't point to one singular event for giving the natural-food movement this kind of momentum." Books such as Eric Schlosser's "Fast Food Nation," Michael Pollan's "In Defense of Food" and "The Omnivore's Dilemma," and powerful documentaries such as "Super Size Me" and "Food Inc." have awakened people to issues in the fast-food model. Fast-casual restaurants, like Chipotle and Panera, have had a huge effect on making higher-quality "food with integrity" widely available at a price most people can afford. Couple that with changing consumer attitudes, and you have the perfect storm to incentivize companies to make these kinds of changes.

Bret Thorn, senior food editor of Nation's Restaurant News, sees something else at work. "This is all an attempt to capture the hearts of millennials," he says. "The big chains are trying to figure out how to stay relevant with a younger audience. The reasons for the changes are also monetary: A recent report in "Fortune Magazine" points to big losses and a mounting distrust of Big Food. An analysis by Credit Suisse's Robert Moskow found that that "big" had become "bad," and that the top 25 U.S. food and beverage companies have lost an equivalent of $18 billion in market share since 2009. The market is sending a clear message to these companies: Adapt, or die.

What does all this change mean for you - aside from better ingredients and more transparency? While Chipotle and Panera say they don't expect to see an increase in pricing, chances are you will see a slight uptick. But, we're getting what we pay for. Are we willing to shell out cash if it means eating food prepared without yoga-mat chemicals?

As for the future of big food, significant changes like these trickle down to smaller players. For instance, Panera's suppliers have agreed to reformulate their recipes to comply with their "No-No List," as have many of Chipotle's. This whirlwind of change adds up to one epic moment in food history. You may not see grass-fed burgers on freshly baked, heirloom-wheat buns at McDonald's tomorrow, but there's hope on the horizon.