I suppose you all know that Starbucks "fine-tunes' its water so that it tastes exactly the same as it does at corporate headquarters. This is accomplished by in-store water treatment and an occasional visit from a certified Starbucks "water doctor." They do so in order to be certain about a new drink's taste once it's distributed to the field.
However, what you may not have known is what whistle blower Nathan Walsh is now claiming. Specifically, that Starbucks adds a mild diuretic to their water that winds up in all of their drinks.
The purpose? To get that drink and some of your body's own water out of you and to get you back up to the register as fast as possible.
So the next time you get the feeling that your double latte went right through you, try sampling a glass of their plain water and see if it doesn't have the same effect.
Thanks, Nathon