I agree- find the one you like, and perhaps without any other additions like sugar or milk, you might lose weight. Also, don't drink your oolong tea with a big mac or something dumb like that.
I think studies have shown more prevalance with oolong and green teas because of the practice of not adding sugar/milk as you would with many black teas/black tea blends. Who knows?
If anything, the caffeine in tea can give you a boost in your metabolism, and I do find that tea curbs my appetite (to an extent). But if I'm having my afternoon cuppa, I need to have something with it- green tea cookies or some Walkers shortbread. hehe. Otherwise, in the morning I drink a lot of tea with my breakfast or fruit, and it helps keep me satisfied until lunchies.
Spacesamurai- that event in the supermarket makes me really, really, really sad.