This story is part of Junk Food, Redefined, our new collection of snack recommendations, recipes, and perspectives that celebrate an undervalued food group. Read all the stories here.

“We fed beef lovers a Whopper with no beef,” says the silky voice over in a Burger King commercial promoting the Impossible Whopper. When the ad aired in 2019, the brand had just released the burger in over 7,000 stores across the U.S. In the clip a man in a checkered shirt and rancher’s hat tucks in. “Turns out these beef lovers love plants too,” the voice continues. Cut scene back to the cowboy, who has just found out his burger contains no cow. “Well, I’m a damn fool,” he drawls, smirking at an off-camera interviewer. Then: A glamor shot of the vegan patty, sandwiched between two buns, looking glossy, delicious, and a heckload like beef.

Burger King isn’t the only fast food chain jumping on the fake meat bandwagon: KFC, White Castle, TGI Fridays, Del Taco, McDonald’s and more are adding meat alternatives to their menus. And let’s not forget Impossible Foods, Beyond Meat, and other faux meats that Americans can now readily find in the grocery aisle. A whopping (heh) 41% of us have tried them and alt meat could be worth $140 billion (or 10% of the meat market) by the end of the decade, according to one projection. Unlike vegan proteins of the past—the seitan crumbles, black bean burgers, and tofu dogs that peaceful and loving Baby Boomers ate in the ’70s—the fake meats of today are decidedly more prolific, thanks to a winning combo deal: Big Tech cash and meaty-flavor mimicry, mass existential dread about the climate, and some very clever marketing.

Concern for our well-being is one of the biggest drivers in fake meat sales; many of us think we’re healthier without any real proof of the fact. “The term plant-based conveys a health halo,” says Larissa Zimberoff, an investigative journalist and the author of Technically Food. Even though, “depending on the burger, it could be ultra-processed” and full of ingredients like fillers and additives, she explains. Part of this perception that fake meats are healthier is formed in direct contrast to beef, “which has been demonized as harmful to health and bad for the environment,” says Amy Bentley, PhD, a professor of food studies at New York University. And the other part, she says, is by association: products that are pitched as ethical or climate-conscious might be automatically considered nutritious, too. It’s easy to see why: Impossible’s website features an image of a cracked-open, fresh-looking coconut to represent the oil in its ingredients list. And Beyond’s Instagram account is peppered with celebrity endorsements highlighting its products’ nutrition facts, like the high protein content, alongside strong better-for-the-planet claims.

There’s no doubt fake meats are on the rise. (Big Meat is mad as hell about it!) And omnivores like me are pleasantly surprised by the taste and texture of these products. But what are they actually made from? And how healthy is fake meat anyway?

What are alternative meats made of?

Today you can buy fake bacon to layer onto your favorite BLT; vegan chicken nuggets to bake up on game day; ground, well, not-beef to fry up into picadillo or sloppy Joes; and burgers and sausages galore.