i understand that the more water you drink the more it will help to lose wight. but now i'm hearing that too much water can gain weight?
which one is true?

Water actually helps to loose weight. because it helps to increase our metabolism rate.
metabolism is the mechanism for burning fat in our body. it burns fat and makes energy. the fuel for metabolism is water. less water = less burning fat.
Taking proper amount of water helps to keep metabolism rate at a satisfactory phase.
So I would say, drinking water helps to loose weight. (Dont' drink too much. anything too much is too much)

The former.
I agree that, of course, when you drink plenty of water (especially before meals) your appetite for food won't be as intense as when you're water-deprived.

Well drinking water is always good for you no matter what so keep it up. As long as you urinate you shouldn't hold too much in. You shouldn't try to lose water weight because as long as you breathe and eat you are guaranteed to get it back through the air and foods.

I think that if you drink it, you LOSE weight, because it has literally nothing in it. It flushes out the bad stuff, and is really good for you.

From my experience, this is a terrible, unhealthy, unsafe way to diet, but I went on a "coffee" diet (basically dehydrating myself) and lost like 20lbs. in 2 weeks (obviously water loss, but it worked for me p).
About a year later I did a water diet (drank a lot) and lost nothing for 2 months!! Talk about disappointed..

Women tend to retain water, so I suppose this is where the weight-gain thing comes from. Of course, if you drink a good amount of water and then do something that makes you sweat, you lose a nice amount of weight in return.

u only gain weight from water if u retain water. but the more water u drink, u lose weight. cold water is better becasue it makes your body burn calories while it tries to warm it up.