I think that I should have at least 1 years supply of food constantly in reserve, and a supply that provides me with at least 2000kcal per
day nutrition (see Daily Nutritional Requirements). This supply should comprise main meals (meat, carbohydrate and veg), subsidary meals such as breakfast, puddings, snacks etc., plus cooks ingrediants, hot and cold drinks, treats and the like.
There are a couple of possible strategies that one might consider:
1. Build up a years supply of long-life "emergency food" and hide it away, ready to be used only in case of that emergency.
This could be "ready-to-eat" emergency meals, which have lifetimes of up to 5 years, or more sensibly, freeze-dried foods with lifetimes of up to 25 or 30 years when supplied in tins.
2. Build up a years supply of "normal" shop bought canned and dried foods (with typical lifetimes of 1 to 5 years).
Both options have their advantages and diss-advantages and as such my personal preference has been to combine the two.
Long-life freeze dried food is expensive and relying soley on this option ignores the real need to store normally used items such as sugar, milk, butter, bread, fryoil etc.
On the other hand, having a large supply of shop bought cans and dried goods can be very wastefull especially if you cannot use items before, or at least soon after the "best before" (BBF) date. What
is really needed with either option is some adjustment (all be it relatively minor) in eating habits, for example to eat more tinned fruit (one can then store tinned fruit without waste), to incorporate
powdered milk into ones diet. whitener for coffee etc.
Whatever strategy for food storage one might chose, one would also need to develop a plan for longer term nutritional survival. Ideas such as a seed bank or keeping chickens (even a small holding)
would need to be seriously considered!