Dr. Stookey answers you
"Does being hydrated help burn calories? Well it is a fact that if you hydrate you will be able to burn more fat, and in some studies we see that it can help people burn more calories but it's only under certain situations where we see that.
And when you drink water instead of something else you’re burning, basically, the calories that you have on board and that helps with weight management. When you are drinking other beverages, the calories that come in the beverages are burned before the calories that you already have on board. So, in terms of what beverage to pick for hydration, definitely water it's a fact, drinking water will help burn fat and calories."