Personally I just carry my emergency food with me.
It’s not directly applicable to survival situations, but check out this pretty wild case report of of a 382 day fast (noncaloric fluids an vitamin supplements given):
http://pmj.bmj.com/content/postgradmedj/49/569/203.full.pdf
“A 27-year-old male patient fasted under supervision for 382 days … Patient A.B. aged 27 years, weighed on admission 456 lb (207 kg). During the 382 days of his fast, vitamin supplements were given daily as ‘Multivite’ (BDH), vitamin C and yeast … Non-caloric fluids were allowed ad libitum. … During the 382 days of the fast, the patient’s weight decreased from 456 to 180 lb.”
I’d be interested to see it quantified what kind of loss of performance (and morale) do you get with a fast or a low calorie diet. I’d wager many armed forces have conducted these sorts of trials (in addition to the nazis).
