Although this has nothing to do with Usha Paana Chikitsa, but as it is also related with water, so I felt like sharing this interesting experiment that a friend of mine did a few months ago.
He was an athlete, and never really had any health issue in his life. But as he become busy with life, habit of playing sports slowly drifted away, and a a result he gained some fats. one day he realized that it is not a good sign, but as he can not find time for sports cause of his busy schedule, he decided to try to alter his diet. And all he did was making a habit of drinking fore liter of water ever day.
He will carry a big 2 liter bottle with him, and whenever he got time, he use to drink it all. This he repeated for three months, and not only his weight came under control, but his overall digestion also improved a lot. He told me that he can not find any other reason for this, except for the fact that he included drinking more and more water in his regular habits. Now he does it regularly, and he is as fit as before ! Kinda surprising, but true !