Filling, shelf-stable snacks that aren't that appealing?

mazdauk

Roasted salted broad beans - you can't get them everywhere, but if you have a Cypriot/Turkish grocer near you you might find them (my Co-op stocks them). 25g is about 100 calories, but they are very salty, so actually half that is plenty. I weigh them out into a tiny Tupperware, and if I'm not desperately hungry they can come and go for days. Same with roasted (not dry roast!) nuts.