Bombs rain from the skies, alien ships descend with lasers ablaze, improbably proportioned, irradiated sea monsters tear through essential infrastructure. You'd think that running, screaming, and finding clean underwear would top the list of activities likely to improve your chances of living, followed closely by finding a sustainable food source and offering sexual favors to the person with the most impressive arsenal. Unless you were a prepper, in which case you'd be worrying more about the safety of your cigarette stockpile.
Other newsletters and books followed in the wake of Ruff's first publication. In 1975, Kurt Saxon began publishing a monthly tabloid-size newsletter called The Survivor, which combined Saxon's editorials with reprints of 19th century and early 20th century writings on various pioneer skills and old technologies. Kurt Saxon used the term survivalist to describe the movement, and he claims to have coined the term.
In the next decade Howard Ruff warned about socio-economic collapse in his 1974 book Famine and Survival in America. Ruff's book was published during a period of rampant inflation in the wake of the 1973 oil crisis. Most of the elements of survivalism can be found there, including advice on food storage. The book championed the claim that precious metals, such as gold and silver, have an intrinsic worth that makes them more usable in the event of a socioeconomic collapse than fiat currency. Ruff later published milder variations of the same themes, such as How to Prosper During the Coming Bad Years, a best-seller in 1979.
Astronauts are provided with survival kits due to the difficulty of predicting where a spacecraft will land on its return to earth, especially in the case of an equipment failure. In early US space flights, the kit was optimised for survival at sea; the one provided for John Glenn on the first American space flight in Friendship 7 contained "a life raft, pocket knife, signaling mirror, shark repellent, seawater desalting tablets, sunscreen, soap, first aid kit, and other items". A survival kit was provided for the Apollo program which was "...designed to provide a 48-hour postlanding (water or land) survival capability for three crewmen between 40 degrees North and South latitudes". It contained "a survival radio, a survival light assembly, desalter kits, a machete, sunglasses, water cans, sun lotion, a blanket, a pocket knife, netting and foam pads".
Untold numbers of people wind up suffering frostbite, shock or hypothermia every year because they didn’t have adequate survival gear when the weather on their wilderness adventure took a rapid turn for the worse. But it doesn’t have to be that way. The Titan 2-sided Mylar Survival Blanket is light as a feather and yet capable of retaining up to 90% of your body heat.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!