There are a number of specially-formulated dieting teas. I've tried one or two from the grocery store, but they tasted a bit too grassy. A local higher-end store has a number of fasting teas. One's oolong, another is herbal (kind of a minty blend), and another is yerba mate. I've stuck to green tea for years for the health benefits, but I feel like trying something different. I think I might go with the yerba mate. Apparently it's on par with coffee!