There are currently two main, buzzy players in the plant-based "meat" market: Beyond Meat and Impossible Foods.
In 2013, Whole Foods gave plant-based meat start-up Beyond Meat its first shot at selling its vegan "chicken" strips at Whole Foods locations across the country. Early believers and investors in the product were billionaires Bill Gates and Twitter co-founder Biz Stone.
"We launched Beyond Meat. We were their launching pad. In fact, I think all of their new products have been introduced at Whole Foods," John Mackey, co-founder and CEO of Whole Foods, tells CNBC Make It.
A year later, Beyond Meat developed its first "beef" product made from plant proteins, which later morphed into its now-famous Beyond Burger in 2016. (The company has since made recipe updates to its original beef patties. In June, Beyond Meat announced its new recipe uses a "blend of pea, mung bean and rice proteins." )
That same year, another plant-based meat start-up, Impossible Foods, released its alternative to the beef burger made from soy protein concentrate to restaurants. Momofuku Nishi in New York City began serving the Impossible Burger in July 2016. The company is also backed by Bill Gates.
Today, both Beyond Meat and Impossible Foods have exploded.
In May, Beyond Meat had the best IPO so far in 2019 surging more than 163% on the day of its market debut, in addition to making big deals with Carl's Jr., Dunkin, Del Taco and TGI Friday's to name a few. And Impossible Foods products are now in about 10,000 restaurants — including White Castle, Red Robin and Burger King — with plans to launch in grocery stores in September.
The market for meat substitutes is expected to hit $2.5 billion by 2023, according to Euromonitor estimates.
But Mackey, who has been a vegan for more than 20 years, isn't sold on the health benefits of plant-based meats.
"The [brands] who are capturing the imagination of people — and I'm not going to name these brands because I'm afraid I will be associated with the critique of it," says Mackey, "but some of these that are extremely popular now that are taking the world by storm, if you look at the ingredients, they are super, highly processed foods."
According to Beyond Meat's website, ingredients for its plant-based patties include water, pea protein isolate, expeller-pressed canola oil, refined coconut oil, rice protein and other natural flavors, including apple extract and beet juice extract (for color). Ingredients for Impossible Foods burger include water, soy protein concentrate, coconut oil, sunflower oil, potato protein, soy leghemoglobin (a group of protein found in animals and plants) and other natural flavors, according to its website.
"I don't think eating highly processed foods is healthy. I think people thrive on eating whole foods," Mackey says. "As for health, I will not endorse that, and that is about as big of criticism that I will do in public."
And Mackey isn't alone. Some dietitians aren't completely sold on the plant-based burger craze either.
"They are not necessarily healthier than beef burgers," Alissa Rumsey, a registered dietitian, told CNBC in July. "They're totally fine to eat, but there's no need to replace your beef burger if you don't enjoy these," Rumsey added, pointing out that both plant-based burgers and traditional beef burgers have the same amount of sodium and saturated fat.
On the other hand, Mackey does believe that plant-based meats are a more ethical choice and are better for the environment than regular meat. And research has backed up those claims.
According to a study commissioned by Beyond Meat with the Center for Sustainable Systems at the University of Michigan, a plant-based burger generates 90% less greenhouse gas emissions, requires 45% less energy, has 99% less impact on water scarcity, and 93% less impact on land use than a ¼ pound of traditional U.S. beef.
According to Fast Company, Americans switching from beef to plant-based patties would be equivalent to taking 12 million cars off the road for an entire year.
Even given his reservations about the health of the products, Mackey says there is at least one good dietary argument for plant-based meat: "A lot of people say ... that [plant-based] meat is a transition food, meaning it's a way for [people] to begin to reeducate [their] palates"; it's a good first step in weaning people off of meat products, he says.
Mackey says most Americans wouldn't enjoy eating like he does (he has 15 fruits and vegetables a day) because their taste buds are used to a diet that includes a lot of processed foods.
"So the reason why these plant-based meats have taken the world by storm is that they taste very similar to regular meats, whereas if you get a [healthy] black bean burger with flax seeds and sweet potatoes in it, that's going to taste great to me," he says, but not to most people.
Mackey says the good news is that people can retrain their palate to "enjoy pretty much anything" by consistently eating something they typically didn't like before.
"I love fruits and vegetables," Mackey says, because he trained his taste buds to love them.
Beyond Meat and Impossible Foods did not immediately respond to CNBC Make It's request for comment.
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