Matt Matros, the owner of this grab-and-go smoothie shop located just a stone's throw from the Sears Tower, has a lot invested in smoothies. He lost 60 pounds on a high-protein diet—and he didn’t stop there. He was so taken with the idea that he quit his corporate job to open this fast-casual spot. Protein Bar’s quick, healthful blends start with a protein base: choose soy, egg or whey in chocolate, vanilla or strawberry flavors. As you move down the line, you pick fruit and liquid add-ins to create a not-too-sweet treat. (Matros’ main concern about the creations served up by most big smoothie chains is sugar content.) If you’re not up for creating your own smoothie, there’s a menu of tested creations, all cleverly named for city neighborhoods and sights (the Millenium Perk, for example, is a blend of chocolate protein, espresso extract and milk).