How I understand it is that you???re supposed to have a three month supply of food you eat on a weekly basis (cold cereal, meat in the freezer, canned veggies and fruit etc) and then have a 9 month supply (bringing you up to a year) of the essentials that will make it so you don???t die if an asteroid hits the planet. (Stuff like wheat, beans, flour, sugar, salt and other stuff).