3x5x.25 worth of food... I'm sorry, I just have to laugh at you CityBoy, and laugh openly. That is what, a couple packs of gum? It isn't enough stable food to worry about.

On the other hand, with a notebook and pencil, you have a multipurpose tool. You can record information for your own usage ("free water at loc.s X, Y and Z"), and for others ("SAR team, Ironraven slept here on 17 Dec 07, broke camp at approx 7am, heading east- intend to reach river, then go south." leave it tacked to a tree by your shelter site.). It gives you tinder. It gives you bait (not moving white and fluttery isn't that common in nature). It gives you something to wrap a small item (tooth, lens, mirror, etc). If it is decent paper, use it pack a hole in your shoe's insole. Give me time, and I can keep giving you uses. A lot more than you get from about three cubic inches of food.