Can someone help me, I heard of my friend that each mouthful food I eat, I have to drink a glass of water. It would be a very nice diet because you dont have any
hunger and u fill your stomach, is it true??

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.

I've heard of a water diet, but it was a different version. It wasn't a glassful for every mouthful, but a full glass of water at least 15 minutes before each meal and one in between meals.

I think a glass of water with every mouthful could be dangerous, as too much water is actually harmful. It's called hyperhydration or something like that. If you live in a very hot climate and sweat a lot it may not be such a problem.

And I heard a different version, which is one full glass of water with each meal, and one glass in between.

I like the idea of drinking the water with the meal, better than drinking it separately. I can go through a lot of water if I just keep it around to sip, but I hate forcing down a full glass.