CamperMom opens up a whole new aspect here. One of my favorite things is to dehydrate shopped spinach and add some to each one-dish dinner. Unless your dinner is mostly spinach, you won't taste the difference, but it is practically weightless and adds nutrition. TVP (soy protein) is a good inexpensive protein source, which takes on the flavor of whatever it's cooked with. (Some folks have digestive problems with it, so, as with everything else, do some home trials first!)

You can do dehydrating in a low oven (usually with the door wedged slightly open, so you can get along without a dehydrator. This method is not, however, recommended for hot weather!