Best way to do it would be to buy a quart of whole milk a day. ~ 760 calories a day. It would be extremely unpleasent, but you would probably survive.
ummm in essence thats 30 or 31 dollars... you go grocery shopping at the beginning of the month and buy really cheap items... and then you get free shit from other ppl. WIN
Assuming you start with $1, and accumulate money as the month progresses, I'd start with one of those cheapo 6 packs of ramen. That's less than $1. I'd eat those while I accumulated money for better food.