Your body is 70% water. So maybe there is some truth to that not only you should drink water at least 25% of your weight everyday, but there are certain times that are best for drinking water. From my personal experience, staying fully hydrated helped me keep my blood pressure low. I also know that if you can manage drinking four cups of water in the morning on empty stomach you can lose weight. Of course, it is not easy keeping the water down at first, but after a while, you’ll get used to it. However, I don’t know whether it’s the water effect or because after drinking four cups of water in the morning, you probably won’t feel like eating anything for the rest of the day.
More on this here: Drink Water: Drinking Water At The Correct Time