Why Does My Under Arm Sweat So Much?

I have a lot of under arm sweat more often than not. May be due to the coffee I only drink in the morning but I am curious as to a remedy that is not along the lines of an antiperspirant due to bad things I ve heard about them. I m a bigger guy. 6 3, 250 lbs. I usually sweat anyway. But the perpiration is usually in my underarm area, unless I am being active, then I obviously perspire everywhere. Days I don t drink coffe I still perspire but not as much. And I have notice that when I use mitchnum antiperspirant I seem to sweat more than when I use nothing. When I use nothing the odor isn t very strong due to I am a very clean person. Any thoughts?