Dominant chains like McDonald's and Burger King have lost market share to fast-casual options like Chipotle, Panera Bread, and Buffalo Wild Wings. 

This chart by Morgan Stanley shows which restaurants have become more and less popular over the past decade. 

While fast casual chains still make up a smaller percentage than traditional fast food or casual restaurants, they are gaining the most traction, the analysts write. 

Chipotle and Panera Bread have gained the most customers. Meanwhile, Burger King and KFC have suffered the most.