I have read up on some of this

and it is suggested that if you drink dark colored beverages (such as coffee, coke (soda pop, pop, whatever you wanna call it) & thick beverages) that you should match the amount with water. It helps prevent urinary/bladder problems. Nothing really to do with the weight issue, but just an FYI for those of us who have frequent bladder/UTI's.
This is a really great topic to bring up. There are so many people who say drink water...as much as you can. The facts laid out are, drinking water is better for you than drinking a coke or coffee, but don't guzzle it. Just drink enough to stay hydrated. Stay away from the sugar!
Don't get me wrong, I LOVE LOVE LOVE my coffee

, but I make darn sure I get my 80 oz of water a day (64oz regular & 16oz to replace the 16oz of coffee I drink). I feel fuller longer and I don't get cotton mouth at night.