This is one of the reasons our international visitors got a poor view of Americans. They'd think "How are you today?" was an honest question, and then get all hurt when the person shut them down. We learned to give that in the primer before visits -- when people ask any variety of this question, the socially acceptable answers are, "Good, fine, and okay." Stick to one of those three. If they actually want to know how you are, they'll ask a followup question, like how you like your accomodations, or if you're finding everything, or if you're recovered from your jet lag, etc. That's when you can give a full answer.