How much water is really needed for a healthy diet?

I was with weight watchers and they say to drink 6 to 8 glasses of water a day.It's good for you.It helps eliminate toxines.

8 glasses of water a day is not only for active people but for all. Active people drink more than 8 glasses a day because they need it to replace lost fluids. For the average person, we still need to drink a lot of water to clean ourselves on the inside. If you are a bit sick like having colds, and you drink plenty of water, in a day or two, your colds will subside. If you don't drink plenty, your colds will last up to 2 weeks. Water is essential!

I would have to say when I was losing weight I was drinking no more than six 8oz glasses of water a day and I would buy a pack of bottled water that contained 500ml. I would use that bottle throughout the day. One 500ml bottle of water would be two cups of water. I would drink one of those bottles with my breakfast, one with lunch and one with supper. They say that drinking cold water is bad for a person so I would have a cup of tea after supper and that's another serving of water as well. It's also not good to over do it with water as it can mess up your kidneys.