Pita or tortilla or other flat bread or crackers with: a can of tuna in olive oil (good fat calories here), can or pouch of chicken, summer sausage, can of deviled ham. Empty tuna size cans surprisingly weigh about the same as the empty pouches, contain more food, are easier to eat out of if going that route, and cost less than pouches as well. The only extra weight needed is a little P-38 can opener
https://www.google.com/search?q=army...hrome&ie=UTF-8 which weighs all of 4 grams.