As for the original question, I haven't come across any research that says it helps with weight loss. Some people feel it fills them up, but I've actually seen research disputing that point, but don't recall how it was conducted. So, I'm not sure it helps with weight loss, per se.
But, you may be surprised to learn that you don't need as much water as we've all been told our whole lives. There's been a lot of research lately around this notion of how much water we need. Here's a good summary of a recent article that has since been confirmed with other research. (A link to the original article is at the bottom of the page).
http://dms.dartmouth.edu/news/2002_h...02_water.shtml
It turns out no one knows where the recommendation to drink 8 8 oz glasses of water a day came from. Seriously! The best guess they have is that
"the Food and Nutrition Board of the National Research Council recommended approximately "1 milliliter of water for each calorie of food," which would amount to roughly two to two-and-a-half quarts per day (64 to 80 ounces). Although in its next sentence, the Board stated "most of this quantity is contained in prepared foods," that last sentence may have been missed, so that the recommendation was erroneously interpreted as how much water one should drink each day."
Also, the research has continued and found that caffeinated beverages are not diuretics. The old wisdom was that the diuretic properties in caffeine took out more liquid than they added seems to be false (it also had never been tested). It may be true for people who have just started drinking caffeine, but quickly reverses itself. So you can count coffee and tea as part of your "water" total.
The conclusion I have come to from this and other research is that hydration IS important. If you like to drink it -- drink it (in reasonable quantities). And, if you are exercising, or sweating, or someplace warm, you do need to watch your hydration levels, it IS important.
But if you don't like to drink water then, for hydration purposes, you probably don't have to worry about getting enough -- much of it will come from your food and other liquids you drink. Hydration is not about JUST water.
Of course, as is often discussed on this forum, there may be other reasons people want to shift to water only, or even to drink more water. But for those who struggle to get all the "recommended" water in, you're probably fine!