Fitness: Safeway

Seeking Supermarkets in Manhattan!

Hi, Just moved to midtown Manhattan and cannot understand why there aren't really large supermarkets nearby--Like Safeway or Stop & Shop (or are they hidden?). Where do people shop for groceries? My neighbors eat out or shop from Food Emporium, which is pricey to me. I don't have a car, but would be taking bus/subway. Can anyone help? Thanks!