I'm glad you brought up Survivorman. Although the show is admittedly a little contrived (he does his best not to be prepared and he does know someone's coming back in a week), it is interesting to watch his "progress." He clearly becomes disoriented and agitated after a day or two with no food. You also see how exhausted he becomes with simple activity and little to no caloric intake. Luckily, I have a few more pounds of fat stored internally for such an occasion.