Where is a good, healthy place for lunch in Oakland, CA near Oakland City Center?

I’m new to the area and am looking for good, healthy places for lunch near the Oakland City Center. I’ve scoped out a good portion of the City Center itself and haven’t found anything I’m that excited about. For purposes of this question, I’m defining “healthy” as having a high ratio of nutrition to calories and being relatively “clean”/low fat. A nice fresh salad bar place would be welcome, for example. I’m not vegetarian, although suggestions for veggie options are also welcome.