Aboslutely. Making a bunch of food all in one shot, and pre-packaging it, is a great time-saver. Pretty much anything goes.
Whenever we're having chicken or steak for dinner, I'll throw on an extra 2 or 3 pieces to have for lunch over the next few days. I'll also try to hard boil a dozen or so eggs twice a week, just to keep in the fridge. There's not really any rules. I've said before "leftovers are where it's at."