I read on one blog about the idea of NOT packing cans, rations, etc,,just pack stuff for survival ‘bread’,,can be eaten raw,,or cooked on any heated surface,,looks like a tortilla of sort,,just has basic calories,,can use it to wrap up other foods. Flour, water and baking soda. A very basic way to get a few calories,,and light to carry (versus cans).
Datrex bars are great. High calorie count, Long shelf life and immune to heat.