Comment by msandford

Animals are comprised of a huge amount of water and some other stuff. I think even meat is something like 80-90% water. But people don't usually say "man I'm thirsty, someone bring me a ribeye!"

When cells are made up so primarily by water saying "oh but this fiber is a trivial percentage" is very misleading. If all sugar is in the water which is contained in cells which are bound up by fiber then the fiber could make it much more difficult for your body to just absorb all the sugar wholesale.