If TSHTF, we may have to self-quarantine, perhaps for 30 days. Nobody and nothing comes into the house. We are trying to figure out how to handle that. If the utilities stay on, the problems seem manageable.
Food is the big question. How much food do we actually need? Calculation shows it to be roughly 50,000 calories per month per person as 1700 grams of fat, 5000 grams carbs, and 3700 grams protein. That is the inventory you need for one person for a month.
On a per day basis, that is:
50 grams fat, 150 grams net carbs, and 100 grams protein
Making that into a shopping list is not difficult. You need about:
10 lbs of dry food (rice, flour, beans, peas, lentils, pasta, oatmeal) — 1/3 lb per day
3 dozen eggs — 1 a day
2 big jars of peanut butter, Nutella, etc. — 6 tbs per day
15 cans of tuna, chicken, and kippers — ½ can per day
15 cans of vegetables — ½ can per day
15 cans of fruit — ½ can per day
10 cans beans and chili — 1/3 can per day
7 lbs of frozen meat in small packages. — ¼ lb per day
1 case of protein vitamin drinks — 1 per day
This list is about 57,000 calories or 38 days, so there is a pretty good safety margin against running out. For two people, double it or triple it for three.
Another safety margin is that this list can go 21 days without cooking anything. The nutritional balance stays about the same.
You will, of course, want to check your medicine cabinet, your spice cabinet, your snack box, your petty cash box, and your gas tank to top them off too.