I have the opposite problem, after one glass of water I feel full and drinking any more makes me nauseous. It’s a struggle to get sufficient hydration during the day.
Sports drinks are basically the same thing, but with excess sugars for “energy” (and weight gain).
When my wife was ill a few years ago the doctor suggested Angel Delight[1] to help maintain fluids. Until then it hadn't occurred to me you're still effectively drinking half a pint of milk when you eat a bowl.
[1] It's an instant dessert / mousse that you mix up with milk. https://en.wikipedia.org/wiki/Angel_Delight