Many people will say or think "1200 calories is about 1/3 of what you need". They are correct, but they've also not offered a better solution for long term heat stable calorie storage.

1200 calories from an ER coupled with a 22 rifle for hunting, a fishing kit, and foraging = staying alive for a long time.

I keep a minimum of 3x 3600 calorie bars in our "BOB". This means we can each go 9 days without any sort of outside caloric supplements. Add fish, game, and forage and this would equal my current daily intake of about 1,500 calories.

The physical exertion required during an emergency would greatly exceed my current somewhat static office life, but we're talking about survival not weight gain programs.