In the past two years... it has become very hard for me to gain weight jubei. Even with moderate AAS use (less than a gram/week)... I can rarely get my bodyweight over 200lbs. However, no matter what I eat, or how much I eat... my BF never reaches anything higher than 10%. My diet, at times, consists of pure crap too: pizza, drive-through, ice cream, cakes, etc. Although, for the most part, I do eat pretty clean. Everytime I eat, my body heats up enough to make me sweat (sometimes quite badly). I believe this is caused by the green tea.
So yeah... I do think green tea can be thermogenic enough to burn muscle. But its guaran-fucking-teed to keep you hard if you drink a few liters/day.