To second what MDinana said, Ramen noodles make a good filler if you have other stuff to put with it. Wild edibles and a bit of squirrel can be stretched into a quite satisfying meal. It is a bit water intensive but on the other hand you'll be drinking boiled water.
They are cheap and useful enough to store for bugging in but not calorie-dense enough to take with us in an emergency. We have better choices for that.
Sidenote: our kids love them so there's some "comfort food" ability with them.
-Blast