With casual-dining rivals such as McDonald's (NYSE:MCD) and Dunkin' Brands (NASDAQ:DNKN) pushing deeper into its coffee space, Starbucks (NASDAQ:SBUX) is set to push back. The company will be rolling out an expanded food menu soon. Fool contributor Demitrios Kalogeropoulos discusses why this makes sense for Starbucks, and what kind of boost it could give to the company's sales.