And I have some Jewish friends who pay close attention to which organization's hashgacha is on the packaging. (These are the ones who, for instance, insist on chalav yisrael dairy products - they don't believe that chalav stam is ever acceptable, it's all chalav akum. There's frum, and then there's meshugah-frum.)
I very seldom use packaged backpacking food. I prepare freezer bag meals at home. But it's about seasoning them to my taste, not about dietary restrictions.