All great answers to this question.
Since you’re asking if water helps with “weight loss” you could say no because water weighs something, therefore if you drink water you’re adding weight to your body. But if you’re asking if water helps with “fat loss” I say, yes. Water transports nutrients consumed to cells in the body. For your bodies cells to be healthy and function correctly, you need proper nutrition/nutrients, and water transports these nutrients to them.
An example would be: An increase in muscle mass increases metabolism, and the higher metabolism you have the more calories you expend during rest/activity, which leads to easier/faster fat loss. In order to increase muscle mass, one needs muscle energy (glycogen) from carbohydrates to push through their intense workouts. The only way your muscles will maximize glycogen stores is via water and sodium.
So in this sense, yes, water is important and helps you lose “fat” as well as keeps your body healthy with all it’s other perks.
All these are great answers, but I wanted to remind everyone that water is integral to almost all the functions of the body. Without the proper amount, you are putting constant stress on the body. I think we need to emphasize drinking proper amounts of water, whether it helps with weight loss or not.
Also, if you are taking supplements, many have caffeine and/or protein. Caffeine can be dehydrating and extra protein puts stress of the kidneys. If you are taking supplements, you need to be even more conscious of the amount of water you drink.
I have always believed that water will aid with weight loss. Its caloric free and helps speed up your metabolism.