Drinking water helps the body to maintain water balance, which can help to eliminate wastes and toxins in the body. This can improve metabolism and help to lose weight. In addition, when drinking water, your stomach will feel fuller, so you may eat less.
Generally speaking, drinking enough water is an important factor to keep healthy, but just increasing water can't help you lose weight independently. If you want to lose weight, you need to change your energy balance by adjusting your diet and exercise.