I’m not going to add much, I’ll just let the doctor have his say in this partial transcript from an Oprah Show episode featuring Dr Nicholas Perricone, which aired in November, 2004
“Oprah: Now I’ve read in your book that you said if I just replaced coffee with green tea instead, that I could lose 10 pounds in six weeks.
Dr. Perricone: Absolutely.
Oprah: Now really. How could that — what is the big deal about this?
Dr Perricone: Coffee has organic acids that raise your blood sugar, raise insulin. Insulin puts a lock on body fat. When you switch over to green tea, you get your caffeine, you’re all set, but you will drop your insulin levels and body fat will fall very rapidly. So 10 pounds in six weeks, I will guarantee it.
Oprah: I’m gonna do that. OK. That is so good! Whoo! That is great.”
— The Oprah Winfrey Show: “Look 10 Years Younger in 10 Days” – Nov 10, 2004
So, even if the doctor is only partly right, given that we’re all individuals who react differently, why wouldn’t you give green tea a try?