I think it would be very helpful. It's mostly psychological. It will make you eat slower, and it will make you fill full faster. Generally, your body feels hungry and gets full based on how much you eat in weight and volume, not calories. Thus, adding a lot of water to your meals will help reduce how much calories you consume. Additionally, eating quickly doesn't give your body time to tell your brain that you're not hungry anymore. Drinking water will slow you down, and you'll stop eating sooner.