I have long believed that the human thirst mechanism is there for a reason and that the whole “By the time you feel thirsty, you’re already dehydrated” thing is probably crap.
I guess that’s just background information so you know where I’m coming from, but I heard something really interesting on a podcast this morning: Too much liquid in conjunction with meals can cause stomach upset, because it dilutes your stomach acid, which then allows food to sit in your stomach and start to ferment rather than being quickly digested. And that might explain why sometimes green tea seems to upset my stomach, which I always thought I must be imagining because it didn’t seem to make any sense.
I don’t typically drink much of anything at meals, but obviously I make exceptions for tea. (I make a lot of exceptions for tea.) But I think, with this new information, I’ll probably avoid all liquids an hour before and after eating and see what happens.