I am not sure there is a strong link between drinking water and a healthy diet (or loosing weight).
Here how it goes for myself :
* Soups is an important parts of my diet. I love them and, it is true, they are filling without bringing much of
help to any form of weight gain
* I avoid sugar in drinks unless I really need the sugar. So it is mostly water. I drink a lot of it and found it
helps regulate my blood pressure (I have been in few cases with too low a blood pressure simply because
having lost too much water)
* With years of workout practice, I have a reach a point where I loose a LOT of water during class or workout.
Although I have never read anything scientific about it, I have heard the healthier you are the more you loose.
So it is quite obvious I have to replace all that water. I do not do that during workout as my stomach likes to
be empty but after ... for hours ..
Enjoy water ! (good water by the way, I installed myself a very good water filtration system)