You don't have to drink more, you asked for advice as to why you weren't losing weight, I gave you a possible answer. We normally only feel thirsty when we are dehydrated already. If we are dehydrated then we retain water, which stops us losing weight- not just water weight but fat weight too. If you don't want to try it for even just a week then don't. It was just a suggestion. I thought you might be willing to try it if you were really keen to lose weight. We can't find out what works for ourselves personally if we don't try different things. I am perfectly happy for you to dismiss the idea as rubbish without even trying it. No worries.