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You stride up to the futuristic counter of this ultra-transparent restaurant and order a burger called Trucker’s Delight for reasons that aren’t quite clear.

“Coming right up,” says the cashier, manipulating a floating, translucent touchscreen. In less than a minute, your burger is on the counter—but behind it, the servers are unpacking the rest of your order: four heaping pounds of steaming cow manure, one thousand sloshing gallons of contaminated water, and a disgusting black sludge that you recognize as the carbon released by a gallon of gasoline. You hear the beeping of a heavy-duty vehicle backing up and look out the window as a huge Mack truck pulls into view.

“What’s that for?” you ask.

“That’s the two hundred cubic feet of the CAFO [concentrated animal feeding operation] lot used to make your burger. It won’t be good for anything else for at least a few years,” says the employee. “Would you like it to go?”

You shake your head in disbelief, suddenly grasping the burger’s weird name. “Is that everything?” you ask.

The employees look at one another, sigh, and put on their gas masks. The cashier pushes a button. There is an earth-shaking burp, and the air is so saturated with the smell of rotten eggs that you gag.

“That’s your methane with a dose of hydrogen sulfide,” says the cashier, her voice muffled by the gas mask. “The methane is twenty times more potent than carbon dioxide.”

You double over and retch, croaking that you’d like to change your order.

“Certainly,” says the cashier cheerfully, taking off her mask. “What would you like?”

You order the McRib. Anything has to be better than this.

Out comes your sandwich, along with six hundred gallons of contaminated water. This time, there’s just two and a half pounds of pig shit and a marginally smaller cloud of methane. Still gagging, you switch to the McNuggets. These turn out to be not as bad—with a ten-piece box, you get a pound of chicken feces, 150 gallons of the foulest water you’ve ever seen, and just a little less methane. But it’s a lot to carry. Curious, you move away from terrestrial beings altogether and try the Filet-O-Fish. You begin to feel hopeful, seeing the pound of fish poop, the handful of parasites, and just ten gallons of dirty water. You could almost feel okay about ordering this—plus, you’re getting hungry. As you reach for your meal, the cashier whips out a cleaver and chops the sandwich practically in half, throwing the smaller portion into the trash can.

“Forty-four percent of fish is thrown away by retailers and consumers,” she says, and shrugs. Your shoulders slump; you give up. You order some fries and shuffle away.

If we were faced with the immediate consequences of our eating decisions on a daily basis, we’d quickly start asking whether they were worth it. Is eating a burger worth all this carbon, all this fouled water, all this . . . well, all this cow shit? As the human pop-ulation grows, we will be directly faced with more and more of these consequences—we may never have to cart our food’s byproducts home from the store with us, but it can’t be too much longer before we see it pile up in our backyards. When that happens, people are sure to start looking for a better option.

If farm animals are such resource hogs, why can’t we all just become vegetarians? Certainly we can stand to cut out the middleman—the animals that concentrate the nutrients of plant matter in their tissues. However, many researchers suggest that concentrated animal protein is key to humans’ functioning at their highest level and getting the most out of life. Evolutionary biology has shown that huge jumps in human brain size coincided with increased animal protein in the diet of our evolutionary forebears. By concentrating huge amounts of energy into a tiny package, animal protein provides fuel for surprisingly calorie-intensive activities like language, critical thinking, and a rich emotional life. Furthermore, only animal protein provides the whole spectrum of amino acids essential to human biology.

Despite the vegetarian fantasy of humans subsisting solely on plant matter, not every place in the world is conducive to growing crops. Many of the places facing the worst hunger simply do not have the right kind of land or weather, or enough water for agriculture. What are they supposed to do, wait for us to ship them our excess food? This “solution” is fraught with problems.

In fact, there is a better option—a much better option. If our fast-food restaurant of the future offered a McMealburger or maybe Cricket McNuggets, your side order would be a lot more palatable: about a half-pound of castings nearly indistinguishable from fresh soil, ten gallons of slightly cloudy water, no methane. And a tiny smear of carbon—the energy that kept the cold-blooded insects warm.

Since most bugs don’t require deboning, there are also big savings in energy and water on the processing end; and because they require far less space to raise and can thus be farmed in an urban area, the fossil fuel required to transport them is minimal. The entire impact of this meal would arrive in a tidy, reasonably sized box. In other words, if you had to personally deal with the impact, this would be the meal you would really want to eat.

As David Gracer says of the animal protein industry, “Cows and pigs are the SUVs; insects are the bicycles.”

An animal’s efficiency at turning food, like grass or grain or fishmeal, into the meat that we buy is called its food conversion ratio (FCR). If it takes two pounds of food to make one pound of meat, the FCR is 2:1. For a steer, the ratio is approximately 10:1; for chickens, it’s around 2:1. The wide gulf in FCRs occurs because each of these animals is working with a different physical apparatus as well as different fuel sources. Cattle take in mainly grass (or grain, in a feedlot environment); pigs and chickens are omnivorous like we are, eating a diet of corn, other grains, and processed animal protein; fish are generally obligate carnivores, eating mainly other fish.

And finally, we get to bugs. Crickets, like chickens, are omnivorous. They’ll basically eat anything they can get their palpi on. Cornmeal, compost, cat food—all are fair fare for the cricket. They have a digestive system somewhat like that of a tiny chicken: instead of a gizzard, they have a crop with hardened parts that act like teeth, grinding up their food. They also have a tiny cecum for fermentation. But the special thing that crickets, along with many other invertebrates (like termites, of course), produce is cellulase—that same enzyme the bacteria in a cow’s rumen use to break down the fiber in plants. Until quite recently, it was thought that the production of cellulase was limited to plants, bacteria, and fungi; but many insect species have been found to carry it as well, in both their mouths and guts. For some evolutionary reason, only invertebrates produce this enzyme directly, but it certainly helps with their digestion of plants.

It’s no surprise then that crickets have one of the lowest FCRs of the potential livestock kingdom, coming in somewhere between farmed fish and chickens, at about 1.5:1. This FCR comes from a highly vegetal diet. Crickets really can live, grow, and produce offspring on a mostly corn diet.

Precious little of a cricket, or a mealworm, or grasshopper, is wasted. Unlike the processing that fish, chickens, pigs, and cows must undergo before their meat reaches the market—and which vastly decreases their overall output volume—insects require little to no deboning, gutting, plucking, or butchering. Insects, like oysters, are generally eaten whole. They also devote less food energy toward building things like bones, hooves, fur, and feathers, which we don’t eat. While the throwaway portion of other animals can be up to 75 percent of their total weight, this is the same percentage of most insects that can be eaten.

Factors such as land space, water usage, and inhumane treatment are the real costs of raising animals like cows that—as your trip to McImpacts showed you—aren’t always directly reflected in measurements like FCR or the commercial sticker price you see in the supermarket.

One cow requires anywhere from two to thirty acres. At the global level, raising cattle uses nearly a third of Earth’s terrestrial surface not covered by ice, a fraction that’s already huge and is constantly growing. Picture a giant cow taking big bites out of the rain forest: 70 percent of formerly forested land in the Amazon is now used as pasture, while much of the rest is used for feed crops. In addition to the methane they produce by breaking down plant cellulose, the combination of cattle grazing and grain agriculture to feed cattle also destroys one of the main ways our planet handles excess CO₂: forests, which inhale CO₂ and exhale oxygen—the necessary opposite of what human lungs do. As forests are cut down to make room for not just cattle, but for the acres and acres of soy and corn to feed the cattle as well, Earth’s lung capacity is steadily diminished. If you’ve ever seen an antismoking ad about emphysema, you know this is not a good thing.

Here are a few more factors in favor of bugs: A cow gives birth to one calf per year. In that same time, a pig can produce twenty-five to thirty piglets, and a chicken lays three hundred eggs. In comparison to these warm-blooded livestock, a cricket lays around a hundred eggs in her three-month lifespan. Assuming half are male, that makes 50 female crickets, each laying a hundred eggs. After three more months, we have 2,500 female crickets; in a year, 6,250,000. One three-month generation later, that number jumps to 312,500,000. If 1,000 crickets weigh a pound, that’s 312,500 pounds of cricket in a year, a weight equivalent to 312 cows. Even if only a tenth of the crickets survive, that’s still equivalent to more than 30 cows.

Most farmable insects don’t need the space that cows, pigs, chickens, or even fish do. Whereas cows need space to graze, chickens and pigs need room to forage, and fish need either roped-off sections of the ocean (with the risk of escape and potential contamination of wild populations) or pools of constantly purified water, insects like crickets and mealworms do just fine in small boxes. Crickets, though they have wings, rarely use them to fly and prefer to spend the majority of their energy walking around eating and mating. Just as most of us would rather live in a city and drive to the supermarket than run down a deer in the woods, crickets do not show signs of ill effects when living in close quarters with their food and brethren. If you’ve ever opened an old bag of flour and found mealworms wriggling around, you know that they are also perfectly happy to reside in small, dark, enclosed spaces.

Despite the high ideals of movements like “slow food” and locavorism, the only currently known way to efficiently produce enough protein to feed Earth’s growing population is to further intensify industrial farming practices. This means doubling down on the factory farming of animals, packing more bodies into smaller areas. This is not good news for cows, pigs, or other animals that need things like space and fresh air. It is, however, just fine for many species of insects. We are running out of options and have exhausted our alternatives. We need an idea with legs. Insects have six of them.

Daniella Martin is an entomophagist, or bug-eating expert. She has been featured in the Huffington Post, The New Yorker, the Wall Street Journal, SF Weekly, and AOL News and has inspired an episode of The Simpsons. Learn more at: girlmeetsbug.com.

Excerpted from Edible: An Adventure into the World of Eating Insects and the Last Great Hope to Save the Planet with permission of Amazon Publishing/New Harvest. Copyright ©2014 by Daniella Martin. All rights reserved.