Fish and veggies for me - seafood mostly comes into play when I eat Japanese. Sushi is incredibly hard for me to pass up. I'd say about 70/30 veggie/fish. Though I'm very fond of eating and making seitan and meat substitutes.

I do it moreso, like dolface said, for how I feel. That greasy, slow, sleepy feeling just ain't for me. That and the way the meat industry is run is just dirty. I'm not doing it so much for animal rights because I do think that free range foods and the like (sustainable, efficiency, etc) are good if thats your thing.

As for a correlation with riding fixed... less is more.