Green tea bad for body-building? I just came across this whille going through Bryan Haycock's HST-FAQ (http://www.hypertrophy-specific.info/iB ... q_book.pdf
Green tea has compounds that block COMT. I stopped using as much green tea when I found that they were anti-androgenic. They not only block androgen at the receptor, they also appear to down regulate androgen receptors.
Green tea is basically an anti-endocrine factor. It seems to reduce the effects of all steroid hormones. I don't mean to freak anybody out, it's just that the flavones (especially epigallocatechin gallate) are well known to reduce the actions of endogenous androgens (and estrogens) as well as even lowering testosterone levels themselves.
Anyway, my point is that, you may never see any significant effect of drinking green tea on muscle gains. Then again, we know that it is having an antagonistic effect, however small, in a direction opposite to what we want with respect to testosterone.
Cultures that consume a lot of green tea of also known to have fewer androgenic "manifestations" both normal (body hair, muscle mass, etc) as well as fewer pathologic manifestations (prostate problems, and other cancers associated with steroid hormones).
Fat is a different story. It clearly helps fat loss by altering catecholamine metabolism and probably a few other things.
Doesn't say much about the amount though. My guess is you'd have to drink gallons of the stuff to get the adverse effects.