I have never understood the heavy lens/light camera/balance theory.
When I hold any longer lens I rest the lens on the base of my left hand so that camera and lens are balanced. The weight of the camera is not important because it is the lens I am balancing and the weight of the camera only moves the centre of balance ahead or back a few centimeters.
I have large hands and although I prefer a camera the size of my 20D or EOS 3, I have never had any trouble holding a smaller Rebel sized camera. There always seems to be room for the index finger on the shutter, the next two fingers on the front of the body and the thumb on the back. The lens/camera rests on the base of the left hand with the thumb and index finger on the zoom and/or focus ring. The upper part of the left arm rests against the chest for stability.
Can other people who have large hands please explain why this is hard to do?
My hands tend to be long and narrow rather than wide and stubby if that makes any difference.