Bulk up a little now so you can miss a meal or two later. One gallon of water weighs just over 8lbs, 8.350 I think. How much of that you willing to tote? Filters and purification are best bet. Food takes up a lot of space in a ruck, my 3 day rations are couple pounds deer or beef jerky, two quarts water, usually 4 or 5 marathon bars, 5 5 hour energy shots. Morning coffee and afternoon tea is nice but can wait. If I have to light a fire it won't be for a cup of Joe. Cans are needless weight, and trash. Keep the stuff you got to cook back with the stove. A pack of sugarless gum is in my first line. Trim that grub down make room for ammo.