Editors' pick: Originally published May 12, 2016.

In the 2013 movie Snowpiercer, a science fiction flick in which the sole surviving remnant of civilization in a frozen world is a crowded passenger train that needs to stay in constant motion, lower-class inhabitants eat gelatinous bars made from insects that look, well, less than appetizing, while the wealthy dine on sushi.

While the premise of the movie may be a bit fantastic, as for the bug bar, you won't have to necessarily wait for an apocalyptic event to enjoy the inventive delicacy and others like it.

That's because the demand for protein has not only launched a bevy of meat snack companies such as Epic and Wilde Brands, it is also inspiring a handful of entrepreneurs and scientists to imagine how to meet this demand in a world with both more people and increasingly limited resources.

Motivated to find a solution, those same entrepreneurs and scientists are cooking up alternative sources of protein made of everything from insects to algae, with products that are already making their way into your local supermarket. And their companies are finding plenty of financial backers willing to fund the development of these futuristic food stuffs.

The advantage of such alternative sources of food is that they use much less water and land.

While the search for solutions to satiate the world's increasing desire for protein is not entirely new, it is certainly coming of age.

Take, for example, the alternative meat brand Quorn.

Just last October, Philippines-based food group Monde Nissin bought U.K.-based Quorn Foods for $830 million from private equity firms Exponent Private Equity and Intermediate Capital Group.

That's a tremendous multiple of the target's 2014 revenue of about £150 million ($217 million), and a good deal more than the £205 million ($296 million) the private equity firms paid to buy the business in 2011.

Yet Quorn's story began in the 1960s, when J. Arthur Rank first developed a protein product coined mycoprotein, which is produced by essentially fermenting fungus.

Rank created the product as a way to feed the masses in a world he believed would soon run out of food. In recent years, Quorn has reportedly grown from the high single digits, percentage wise, to double digits, whereas competitors have seen their sales largely stay flat.

At the time of the deal, Monde Nissin said it made the acquisition because of the health and sustainability of Quorn's products, which include imitation hamburger, turkey, chicken and sausage.

But it is recent innovations such as products made from algae and insects, not to mention meat grown in a laboratory, that are really beginning to generate buzz about the category.

Companies built around these novel protein sources are no doubt hoping to replicate the kind of success Quorn achieved in selling to Monde Nissin.

Publicly-traded TerraVia (TVIA) , which was formerly known as Solazyme Inc. and once traded under the ticker symbol SZYM, is transitioning from a company making renewable fuels from algae to one that is pushing algae as a superfood which can be turned into healthy fats and proteins.

In March, the San-Francisco-based company announced the change in its name and its new focus on food.

"Algae is the mother of all food," said Jonathan Wolfson, the co-founder and executive chairman of TerraVia, explaining that all plants evolved from algae.

Algae as a food source is also environmentally-friendly.

Growing algae as a source for protein uses not only less resources then what is needed for animal husbandry, but also has a higher protein yield per acre than even soy, according to Wolfson.

And from the algae, TerraVia extracts protein and healthy fats that end up in a variety of products made by the likes of Mondelez's (MDLZ - Get Report) allergen-free snack food brand Enjoy Life, as well as WhiteWave's (WWAV) So Delicious creamers and beverages.

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Enjoy Life, the food start-up, was bought by Mondelez in February 2015, and is but one of the many high-growth companies that feature TerraVia's algae-based food ingredients.

TerraVia has even teamed up with private equity firm VMG Partners to form TerraBrands, a vehicle to invest in lower middle market companies with revenues above $10 million that can utilize the ingredients.

VMG is known for investing its money in companies such as nut butter maker Justin's Nut Butter LLC, fruit and nut bar maker Kind LLC and Vega Co.

Meanwhile, Vega, a maker of plant-based protein powders and bars, was bought by WhiteWave for $550 million closing in on a year ago.

VMG's interest in TerraVia and its Terra Brands partnership with the company comes from the potential VMG sees in algae as a food source in addressing major challenges the world faces, including sustainability, global warming, hunger and obesity, said Kara Cissell-Roell, managing director of the PE firm.

And TerraVia and its co-founder Wolfson have perfected the taste and texture of the protein made from algae, Cissell-Roell said. According to Wolfson the texture is close to meat and the taste is similar to toasted pistachio.

VMG's track record suggests that we will be eating even more products containing algae in the future.

Perhaps just as intriguing, though in some consumers minds perhaps less palatable, is using insects as a source of food.

Forget the slimey gelatinous bars featured in Snowpiercer, however.

Exo, perhaps the most famous of the start-ups marketing insect-sourced protein, was founded about three years ago by Greg Sewitz and Gabi Lewis.

The duo, freshly graduated from Brown University, took on the challenge of trying to sell cricket flour to consumers as a healthy and, more importantly, sustainable source of protein.

The cricket flour, however, is but one ingredient in the company's protein bars, which come in the flavors of banana bread, cocoa nut, blueberry vanilla and apple cinnamon.

The taste of the flour on its own is fairly neutral, perhaps coming closest to toasted grain, Sewitz explained. As an ingredient in a flavored bar, it is undetectable.

In addition to buying Exo's products on line, shoppers can also find them at retailers such as Equinox Holdings Inc.'s gyms and supermarket chain Wegmans Food Markets Inc.

While eating insects has been around for hundreds of years in some parts of the world, it is still a rather fresh concept to the U.S. market.

Even so, the products have gained enough traction that Exo was able to raise about $4 million in a first round of financing, Sewitz said. The company's valuation was not disclosed, nor were its investors.

For consumers willing to add the new source of protein into their diets, they will be excited to know that there are 1,900 species of insects that have been identified so far around the world, according to Sewitz.

And like the other products on this list, insects are a sustainable source of food, making them perfect fare, apocalypse or no.