I think it’s diet. I stopped eating shit and do not need or want water until around dinner time typically. I am not dehydrated at any point, urine is completely normal and not dark at all.
I have a morning latte and noon coffee (8 ozs each) and feel no thirst until around 3-5 pm. Usually up at 7 am. It’s one of the many interesting changes I’ve noticed since changing my diet.