Work out question

Well maybe it's not a work out question, more like an eating after a work out question.

So you know how you're supposed to eat within 15-20 minutes of working out? Why? I get it if you're hungry because it goes directly to the the muscles or something, but when I work out, I want to throw up...so really, eating is definitely not what I'm thinking about after I get done working out. If you're not trying to "bulk up" but either slim down or tone up, does it matter that you don't eat 15 minutes after you get done working out as long as you don't eat bad food when you do decide you're able to eat again?

Just curious. I don't even know if I'm asking this the right way.