"Drop the scissors, and step away from the plant".

The large leaves are refered to as fan leaves. They store the nutrients and minerals, and photosynthesize like crazy, using light and chlorophyll to convert CO2 and H20 into sugars. (Readers Digest version) Removing them unnecessarily, isn't a good idea. Stunts growth and stresses the ladies.

Some gardeners trim the undergrowth because they feel it's a wasteful expenditure of the plants energy, but I leave 'em and use 'em after harvest for the re-veg process. (Rusty's Bonsai Downsizing thread)

But, to remove the fans to unshade the undergrowth is counter-productive. The fans are more important. :thumbsup:
(some exceptions may apply, like the Screen of Green technique...)