One mistake that I notice some preppers making is not storing enough dietary fat. Everyone stores grains, dry beans, other dry goods. Not everyone stores vegetable oil. Why?
We are all bombarded with subtle and not-so-subtle messages in the media, suggesting that fat is bad and that fat-free and low-fat foods are best. It seems, at times, as if dietary fat were some evil to be avoided at all costs. But in terms of nutrition, dietary fat is essential. You can’t live without fat in your diet. And the ideal healthy diet, for most persons, is not a low fat or very low fat diet.
The American Heart Association currently recommends that most adults obtain 25 to 35% of their daily calories from fat.  The AHA says that “very low fat diets represent a radical departure from the current prudent dietary guidelines”, and therefore this type of diet cannot be recommended.  The AHA cautions that a low fat diet can worsen your triglycerides and HDL-cholesterol levels.  A moderate intake of fat is best for most adults. (But if your physician puts you on a low fat or other special diet, that’s another story. Always prefer your physician’s advice over posts on this (or any) blog.)
Which oils are best for long-term storage? I would shy away from soybean oil and canola oil. Both those oils contain some trans fats, which have no health benefits and many be harmful in relatively low amounts.  I keep some flax oil in the refrigerator; it’s high in essential fatty acids (omega-6 and omega-3). But flax oil is notorious for going rancid quickly. You can freeze some plastic bottles of flax oil, or keep some in the frig. But for long term storage, you need other options.
One good choice is extra-virgin olive oil. Olive oil is a good source of omega-9 monounsaturated fats. Many medical studies have found health benefits from olive oil, especially in reducing risk of heart disease.
A study of over 40,000 persons, published in the American Journal of Clinical Nutrition (July 2012), found a 7% decrease in risk of all-cause mortality and a 13% decrease in risk of CVD (cardiovascular disease) mortality for each incremental increase in olive oil of just 10 g (~2 teaspoons).  The highest intake of olive oil, at ≥29.4 g/d (≥ 2.2 tablespoons/day), provided the greatest benefit: 25% reduction in all-cause mortality, a 44% reduction in CVD mortality, and no reduction in cancer deaths, but a 38% reduction in death from other causes (diseases other than CVD and cancer).
Should you choose extra virgin olive oil (EVOO) or refined olive oil? The latter has a lighter color and a lighter taste, and it is less prone to smoking when used in cooking. But EVOO is high in phenolic compounds, a type of micronutrient with beneficial health effects. A study, published in Atherosclerosis (July 2005), compared refined olive oil to EVOO. The study found that the EVOO, with its higher phenolic content, lowered systolic blood pressure and also lowered markers of oxidative stress (e.g. oxidation of LDL and lipid peroxide levels) more than the refined olive oil.  So while refined olive oil offers the benefits of monounsaturated fat, extra virgin olive oil further improves health by its content of polyphenols.
 Lichtenstein et al., AHA Scientific Statement, Diet and Lifestyle Recommendations, Revision 2006; Circulation. 2006; 114: 82-96.
 Lichtenstein et al., AHA Science Advisory, Very Low Fat Diets, Circulation, 1998; 98: 935-939;
 Krauss et al., AHA Scientific Statement, AHA Dietary Guidelines, Circulation, 2000; 102: 2284-2299;
 American Heart Association, Heart.org, Getting Healthy, Fats and Oils, “Trans Fats Q&A”.
 Buckland et al., Olive oil intake and mortality within the Spanish population (EPIC-Spain); American Journal of Clinical Nutrition. July 2012 vol. 96 no. 1, p. 142-149.
 Fitó et al., Antioxidant effect of virgin olive oil in patients with stable coronary heart disease; Atherosclerosis. Volume 181, Issue 1 , Pages 149-158, July 2005.