"I want to prove that it's good for something, but I don't care what it's good for" is not really a good research question. Then you'll measure 100 things and o

"I want to prove that it's good for something, but I don't care what it's good for" is not really a good research question. Then you'll measure 100 things and only publish the one that makes your intervention look good and possibly ignore all the ones that make it look bad. It's also rather useless if you don't at least have some idea of the mechanism. Coffee has lots of different parts, so what part of it is useful - is it the caffeine? The tannins? ...? And how does it have this effect? Is it even the coffee or just that the coffee group took 5 minutes of rest to drink their brew and that is really the effect?