hey, OP here... Researchers are still out to lunch as far as tea goes with: weight loss, cancer prevention, anti-aging, and diabetes as many conflicting studies have been made. The affects L-theanine, and the combination of L-theanine with Caffeine have been studied and there has been little variance in their conclusions. Myself, along with a few other tea industry-ites have been following these reports. We scoff at all of the weight loss tea spam out there and question each study that comes out. This is only to serve as a culmination of several studies done specifically about the combination of L-theanine and Caffeine. Enjoy! Questions? Find me on twitter: @worldoftea