Hard bread.

Due to its ease of preparation and storage, hardtack has been a staple food for travelers and armies for centuries.

One of the oldest hardtacks is 150 years old! Dried beans.

Likewise, dried beans are easy to store and can be kept safe from weevils for a long time simply by placing them in jars or containers.

Also a good source of protein and nutrients.

Honey and sugar.

They all have a long shelf life, and the sugar can also be used to preserve other foods, such as jam.

Honey is said to be immortal, but even if I found it in an ancient temple, I wouldn't take my chances.

Beef jerky.

Making jerky requires a lot of effort and the yield is low after removing a lot of water, but jerky is an ancient food that many civilizations have survived on.

Too tough to eat? Throw it in the pot and simmer.

Dried salted fish.

Not only does this high-sodium fish last a long time, it's also a great source of salt when your body is low on salt.

The Vikings are said to have eaten salted fish as part of their rations on long journeys and cooked them into a kind of stew or soup.

Salt.

Found in oceans, salt marshes, and even in the Himalayas, salt was once used as currency and is a food that never spoils.

Season your food well, preserve extra harvests or hunts, and replenish any salt lost from your body.

By the way, if you are desperate and can't find salt, go to Animal Farm.

They usually have chunks of salt for the cattle to lick.

Edit: Some quora netizens pointed out that salt is not a food, but a mineral.

Yes I know.

But then the spices aren't considered food because no one actually eats them, but are used to flavor food.

Anyone tried cinnamon? Nope.

Yet they are considered food, or the stuff of food.

So if anyone is nitpicking, humans are not humans because it's just a combination of different elements, like water.

One problem with preserving food for long periods of time is that fat breaks down.

Fats go rancid and smelly, and animal fat goes through the process of saponification after being frozen for a long time; basically it turns into soap.

Therefore, the trick to long-term storage is to choose fat-free foods, dry or freeze them, and avoid exposure to air and light.

Rice, sugar, tea, wheat berries, dried kelp, beef jerky, salt cod, honey, wine, whiskey and other spirits, canned brown bread, and most fat-free biscuits will keep for decades.

Many other foods that are sealed well enough to prevent oxygen and moisture from escaping can be frozen for decades, such as vacuum-packed lean meats.

Sealed, dehydrated foods such as dried fruits, vegetables, and jerky can be stored for years if sealed.

Canned foods can be stored for a long time without being exposed to moisture.

Sealed flours and grains also keep for a long time.

If the nuts are not infested by insects, they can be stored for a long time.

It's usually moisture, bacteria, or bacteria from the handling process that spoil food, whether it's dried, canned, or natural.