You’re preparing for an emergency. Of the three basic necessities, food and water are likely the two you’re worried about the most (the other being shelter). Stockpiling is an easy, relatively inexpensive method of getting through an emergency. The questions are, How much food should I stockpile? and How long is it practical to rely on a stockpile?
Let’s look at basic caloric requirements. According to the US Adult Recommended Dietary Allowances (RDAs), the average female requires 2200 kcal per day and the average male 2900 kcal. If you’re over 50 you need less (1900 female, 2300 male), and children are a whole different ballgame. Note that these are average values, and your requirements may vary. If you want to check out your specific requirements use this calculator.
For our purposes here we’ll ignore children and simply examine the needs of an average couple. Their nutritional requirements total 5100 kcal per day. Protein and carbohydrates provide 4 kcal per gram, and fat provides 9 kcal/g. For a 30-10-60 dietary ratio of fat-protein-carbs, our average couple will need 170g of fat, 130g of protein and 760g of carbohydrates daily. Based on the approximate nutritional content of typical foods, that total of 1060g (or 1.06kg) will translate into roughly 2.5kg of actual food.
The Canadian Red Cross recommends that you stock 2L of water per person per day (pdf). That seems like a lot, as I’ve previously seen them recommend 1L/person/day, so we’ll go with that. That’s 2L/couple/day, another 2kg.
At 2.5kg of food and 2kg of water per couple per day, one week’s worth of food and water will be 32kg of food and water. One month, and you’re stocking 135kg. Obviously, your stockpile is not mobile. If you aren’t sure where you’ll end up in an emergency, keep a small stock at home or in your vehicle, enough for one day or to get you to where you main stockpile is.
You can reduce your stockpile by storing only small amounts of water, and relying on your [own /rhahn/hpl/food/water/water_from_soil.html] [means /rhahn/hpl/food/water/DIY_filtration.html] of producing safe drinking water. An easy alternative for short-term emergencies is drinking water tablets. This can cut out the necessity of storing 2kg/day of water, but you’ll still have 2.5kg/day of food to store.
How much food should I stockpile?
As long as you realize that you won’t be able to move your stockpile, as much as you have room for. In other words, if you don’t want to wait out an emergency in your downtown apartment, don’t stockpile there. Stockpile at your cottage, or a trusted friend’s place instead.
How long is it practical to rely on a stockpile?
The only limitation I can forsee is whether the contents of your stock will start to go bad on you, so check expiry dates. You should also realize that you will become mighty sick of eating brown beans after a week or two, so you may want to get some variety of foods. It would be a good idea to eat from and replenish your stock frequently.