I think real time would be unbelieveable. You don't kill armies in 30 seconds. You don't travel between three towns in five minutes. And you don't become an experienced adventurer in 48 hours. These games are made fun by condensing reality into a short span of time, providing some sort of rush in combat. Otherwise it be a click and wait for five minutes event!
And no, your character doesn't get fat. That's in Black & White though. With the amount of exercise you get, I doubt you could put on weight. At least you can't starve into a skeleton!
