After reading a number of books, articles, and blog posts on prepping and food storage, I noticed a common deficit in their description of what to store. They emphasize storing grains, canned goods, freeze-dried meals, and similar items. But they give little attention to dietary fat, an essential macro-nutrient.
Now I know that in modern Western culture, there is an emphasis on dieting, on low-fat and fat-free foods. You have seen this bias against dietary fat in advertisements and in product packaging, basically saying that you should buy a particular food because it has little or no dietary fat. If you are a little over-weight or are on a particular low-fat diet, then I suppose that is fine. But fat is, in fact, necessary for health and for survival. Your body literally cannot survive long-term without any dietary fat. And that is why food preparations for emergency preparedness must include sufficient dietary fat.
If there is an emergency situation, one that lasts more than a few weeks, you might need to rely, in part, on stored food. You might also be burning more calories than normal. A sedentary adult male uses about 2200 kcal per day; a sedentary adult woman uses about 1800 kcal per day. The USDA nutrition labels that assume a 2000 kcal diet are using an average of those two numbers. But if some disaster strikes, and if it affects your basic needs (food, water, shelter, etc.), you might be more physically active than usual.
Stored dietary fat has a high caloric density. One kg of vegetable oil is 8,840 kcal, but it weighs only about 2 pounds and does not take up very much space. So not only is fat an essential nutrient, but it is a good source of caloric energy.
How much dietary fat do you need? If you are overweight and sedentary, then perhaps 20% of your daily calories should be from fat. But if you are more active, 30% is a better number. The range of fat intake suggested by the Institute of Medicine and the CDC for healthy adults is 20% to 35% of daily total calories. At 2000 kcal per day, 30% is 600 kcal or just under 5 tablespoons per day. At 2500 kcal, 30% is 750 kcal and just over 6 tablespoons of oil per day. You will probably get some dietary fat directly from foods that you eat, and so the amount of vegetable oil that you use would be less. At 5 tablespoons per day per person, you would need 75 ounces of vegetable oil per 30 days per person.
What type of vegetable oil is best for storage? As a source of dietary calories, any edible palatable vegetable oil will suffice. As a source of essential nutrition, you need two types of fat:
1. omega-6 fatty acid (linoleic acid or LA)
2. omega-3 fatty acids (alpha-linolenic acid or ALA)
All dietary fat is a chain of carbon atoms, with nothing but hydrogen (and other carbon) atoms attaches, except for a carboxylic acid group (HO-C=0) at one end. So dietary fat is technically a type of acid.
About 30% of your dietary fat should be essential fatty acids (omega-6 and omega-3) and the ration of omega-6 to omega-3 should be somewhere between 2:1 and 5:1. Medical and scientific experts do not agree on the exact best ratio. The Institute of Medicine’s Dietary Reference Intake values for essential fatty acid have about an 8:1 ratio (but no specific ratio is stated).
The best vegetable oil for storage is probably canola oil, which is about 27% essential fatty acids: 18% omega-6 and 9% omega-3 (for a 2:1 ratio). Soybean oil is about 50% omega-6 and 7% omega-3 (a 7:1 ratio). Sunflower oil and peanut oil are each about 32% omega-6 with little or no omega-3. Safflower oil is too high in omega-6 (at 75%) to be your main source of dietary fat. Flaxseed oil and camelina sativa oil are each too high in omega-3 fat. Camelina oil does keep very well, for over 2 years without refrigeration. But flaxseed oil lasts only a few months with refrigeration. Palm oil keeps well, but is only 10.5% omega-6 and 0.3% omega-3. Corn oil has too much omega-6, at about 59%, and little or no omega-3. Olive oil is too low in essential fatty acids, with only 8% omega-6 and little or no omega-3.
I would recommend canola oil as the main source of stored dietary fat. Most store-bought brands are marked with a use-by date of 1.5 to 2 years from the time of purchase. You can easily rotate vegetable oil, a common kitchen staple, through your pantry. At 75 ounces of vegetable oil per 30 days per person, six months’ supply is 450 ounces of oil, or about 9 (actually 9.375) of those common 48-ounce containers of oil per person. This might seem like a lot of oil, but it is a complete supply of dietary fat for one person for six months. And vegetable oil is probably one of the least expensive, and most essential of your stored food items.