What is meat?

Back in the day, the distinction was simple. Animals are meat, and plants are not. But now, it's getting a lot more complicated thanks to cultured, or what some might call "fake," meat.

Companies like Impossible Foods and Beyond Meat are using science labs and farms, rather than animal meat, to create products that rival traditional grilling staples like burgers and hot dogs.

The U.S. Cattlemen's Association is looking to draw a line in the sand and launch what could be the first salvo in a long battle against plant-based foods. Earlier this month, the association filed a 15-page petition with the U.S. Department of Agriculture calling for an official definition for the term "beef," and more broadly, "meat."

"While at this time alternative protein sources are not a direct threat to the beef industry, we do see improper labeling of these products as misleading," said Lia Biondo, the association's policy and outreach director. "Our goal is to head off the problem before it becomes a larger issue."

Not everyone sees it that way. Ethan Brown, founder and CEO of Beyond Meat, said consumers already know what they're looking for when they're browsing the grocery store aisles. But he doesn't necessarily see the petition as a bad thing.

"I think it actually could help us more than it could hurt us because it starts the national dialogue around what really is meat, and if the origin of meat really matters to the consumer," said Brown.

The cattle ranching group contends that if a product is going to be labeled "beef," it should come from the flesh of cattle. And that means products like veggie burgers and Tofurky won't make the cut.

While these foods are commonly dubbed "fake meat," there's a little more to the meat-substitute market than that. The Good Food Institute, which advocates a sustainable food supply, breaks it down into two categories: clean meat and plant-based meat.

Clean meat refers to "meat" grown in a lab from a small amount of animal stem cells. This kind of meat isn't on the market yet, but it's in development. Plant-based meat is anything that mimics traditional meat but is made mainly using plant ingredients.

For example, Beyond Meat is a plant-based protein producer that manufactures food products in a factory without using animals. It's Beyond Burger is so "meat-like," it even made its way into the meat aisle of grocery stores.

And it's not just vegetarians eating the plant-based burgers.

"From the consumers we see going to the meat case to buy our plant-based burgers where they're sold, we see about 70 percent of those are at least flexitarian, people that have meat in their diet as well as non-meat protein," said Brown.

Data from HealthFocus International show that 60 percent of U.S. consumers claim to be reducing their consumption of meat-based products. Of those cutting back, 55 percent say the change is permanent. So for companies cashing in on the growing plant-based food market, a naming war could make for a rocky relationship with the beef industry.

"We think that the cattlemen could face their competition head on," said Jessica Almy, policy director at the Good Food Institute. "Or like Tyson and Cargill, they could invest in the future. But rather than do that, they're petitioning the USDA to police the use of certain terms on labels and skew the playing field in the cattlemen's favor."

Inviting the government to weigh in on commercial speech raises concerns about the First Amendment, Almy added.

"I certainly think that with this petition, the cattlemen are asking the USDA to set itself up to lose in court," said Almy. "I think their proposal would violate the First Amendment if the USDA adopted it. The government only has the authority to regulate free speech, like telling plant-based and clean-meat companies how to label their products, if it's necessary to ensure consumers aren't misled."

To be sure, this isn't the first fight over food labeling. The dairy industry, for example, has had legal battles over product names like "butter" and "margarine," or "milk" and "soy milk" for years. Dairy farmers want to make terms like "milk" and "yogurt" exclusive. More than 20 years later, there's still no consensus.

Now, we're seeing a similar conflict with the cattlemen. And time may be running out for the government to pick a side in the labeling debate. Allied Market Research has said the plant-based industry could bring in $5.2 billion in sales by 2020, and that means a lot more "fake meat" products will be hitting the shelves.

"I think that clean meat and plant-based meat will make up the majority of meat purchases by 2050," said Almy. "This is just the beginning of a very, very big trend in the food industry. And I think that this is going to be the default meat that you get if you don't think about anything else."

So while some see plant-based food products as a fad, others see them as a revolutionary force in the food industry. And sooner or later, U.S. agencies are going to have to make a call.