I found this short piece, "A Call for Sleep" to be an interesting and honest read. Throughout my life, I've had non medical people tell me that I should be used to a lack of sleep because of my training and night shifts (which I, thankfully, no longer do). If someone has fasted before, that doesn't mean she doesn't get hungry when she doesn't eat!
For applicants, I'll again say that it's critical to consider lifestyle and priorities when choosing a specialty.