does RSS suck up bandwdith?

i know these kind of posts are a little techie for some on the
list(maybe not), but this stuff is good to learn.
we're really in the middle of a lot of development.
people are building the foundation for what's to come.

Question:
do RSS readers use my bandwidth when they check for new feeds?
and if i have an enclosure in a post, does it suck up even more bandwidth?