There's a good topic on this that you can find
here - Lady Z gives some really useful tips!
I think the best advice for your dilema is to place restaurants, not food stands. They completely fill all of the guests needs and hold a lot of people. And restrooms/trash cans can decrease guest hapiness, and placing restaraunts means you don't need those things.
And remember happy animals = happy guests! They won't be
quite as upset over low needs if they're always seeing well kept animals.
Welcome to ZA, btw! :original: