Back in my pre-teen years in the 80s (my era of "I need Gygax/TSR to tell me how to do this properly!") I would furiously tear through my Expert D&D and Dungeon Masters Guide looking for the rules for thirst and starvation. I mistakenly believed that I had somehow missed them while reading the rules; it couldn't be an omission, or else why would they have food and water in the equipment lists, nevermind Expert foraging & hunting rules?
Eventually "improved" editions of D&D included rules for such (and a million other) situations and I was satisfied... until I turned my back on such ways and returned to my youth with confidence and a DIY perspective.
Anyways, I'm editing together an OD&D rules & houserules booklet for my own game, and I decided to do some research on the rules for the OD&D-referenced Outdoor Survival Avalon Hill boardgame; although I was unable to find a PDF of the rules, I did find the following on Boardgamegeek:
BTW The numbers in the "Life Level Index" track seem to be the movement allowance; you run out of food and water? Good luck getting back to civilization...
(I love the icon for the 0 movement section of the track; new Blogspot avatar perhaps...)
BTW, does anyone have a PDF with the Outdoor Survival rules? Abandonware and all.