“Girl dinner” this is not.

In a social media trend that won’t stop, ravenous meat eaters, mostly men, show themselves chomping on rib-eye steaks, bacon and innards.

In a recent online video, a popular TikTok user who posts as @carnivoreray unveiled a new snack recipe. After sliding sheet pans packed with fatty bacon strips into the oven, he melted two sticks of butter from grass-fed cows. Once the bacon was crisp, he poured the melted butter into the sheet pans. Then he popped the concoction into the freezer.

The next morning, the influencer bit into the frozen treat while filming himself for his roughly 170,000 TikTok followers. “This tastes like candy,” he said. (The person behind the account did not reply to requests for comment.)

The video belongs to an enduring social media genre quarterbacked largely by muscular fellows who claim that a meat-heavy diet is the key to mental and physical well-being.

A stricter version of high-fat, low-carb regimens like the Atkins diet and keto, the carnivore diet consists of meat, seafood and eggs — period. While some add dairy and a little fruit to the mix, the strictest proponents adhere to what they call B.B.B.E — that is, beef, bacon, butter and eggs.

TikTok and Instagram are awash in videos of these men (and some women) feasting on a petting zoo’s worth of meat products. Some boast about having not consumed a vegetable in months. They also claim health benefits including drastic weight loss and sharpened mental acuity. Some of the so-called “meatfluencers” forgo not only carbs but also dishware, eating straight from the cutting board.

Health experts are skeptical of the health benefits of the carnivore diet — indeed, it “really bucks nutrition science,” said Whitney Linsenmeyer, an assistant professor of nutrition and dietetics at Saint Louis University in Missouri. But the lack of endorsement from the medical establishment may add to its appeal.

The protein-and-fat-heavy eating regimen has been promoted by the podcasters Joe Rogan and Lex Fridman, influential figures in a testosterone-fueled segment of the media often called the “manosphere.”

“I feel by far the best when I eat only meat,” Mr. Fridman, a computer scientist, said during a 2023 episode of “The Lex Fridman Podcast.”

His guest that day was the psychologist, author and fellow podcast host Jordan Peterson — also a carnivore — who credited the diet with having healed his chronic psoriasis and gum disease.

“I don’t like to talk about this much, because it’s so bloody radical, and I don’t like to propagate it, but this diet seems to have stopped all of that,” Mr. Peterson said on the show.

The paeans to meat have come in the wake of a 2017 appearance by Shawn Baker, a buff orthopedic surgeon, on “The Joe Rogan Experience.”

In an interview for this article, Dr. Baker said he had turned 50 the year before he went on Mr. Rogan’s show, a time when he was dissatisfied with his health, experiencing chronic knee pain and gut issues. Although he had recently shed 50 pounds by limiting his intake of carbohydrates and calories, he suffered from a general I’m-getting-older malaise.

Then he encountered “this crazy group of people online who were eating an all-meat diet,” he said. He decided to try it for 30 days, despite concerns that a person’s “colon would fall out from lack of fiber” on the regimen.

“I do the diet and feel fantastic,” said Dr. Baker, speaking by phone from his home in suburban Seattle. “And then I go back to my old low-carb diet and feel worse.”

He wrote about the diet that he had embraced — and also named, he said — in a 2018 book, “The Carnivore Diet.” This manner of eating had another surge in online popularity last June, when Mr. Rogan tried it and told his millions of listeners, “The best I ever felt — like, literally, the best I ever felt all throughout the day — was when I was on the carnivore diet.”

In recent years, a number of online fitness influencers have risen to fame promoting animal-based eating. They include Brian Johnson, who is known as the Liver King. A Texan with a bushy beard, Mr. Johnson amassed millions of social media followers after claiming that he ate raw meat, testicles, animal organs and bone marrow to achieve his powerful physique. (Mr. Johnson has since admitted to using steroids.)

A plant-free, low-fiber diet goes against accepted views of what constitutes healthy, balanced eating, Professor Linsenmeyer said. Meat and butter are “very high in saturated fat,” she said. “That increases the risk for cardiovascular disease. If this were my patient following this diet, I would be very concerned.”

There is also the matter of contributing to the warming climate, since meat and dairy production are linked to emissions of methane, a potent greenhouse gas.

Promoters of the carnivore diet argue that our ancestors subsisted on animals almost exclusively. Carnivorism, in their view, represents a return to a supposed hunter-gatherer golden age, long before the advent of Cap’n Crunch’s Ocean Blue Maple Syrup and other highly processed foodstuffs.

Paul Saladino, a medical doctor and the author of “The Carnivore Code,” has claimed that most plants are “inedible if not toxic to humans.” “Forget the leaves and fibrous tubers, we’re going hunting!” he commands in the book. (Since publishing “The Carnivore Code” in 2020, Mr. Saladino has reintroduced carbohydrates into his diet, with fruit and honey.)

As a 2023 New Yorker article detailing the carnivore craze pointed out, however, studies of Neanderthals have turned up evidence that their diets included dates, tubers and other leafy foods in addition to meat. According to Herman Pontzer, an evolutionary anthropologist at Duke University quoted in the article, humans are “opportunistic omnivores” who will “eat whatever’s available, which is almost always a mix of plants and animals (and honey).”

The New Yorker also noted a study by the biologists David Raubenheimer and Stephen J. Simpson, who found that protein-loaded diets had a detrimental effect on animals’ life spans. “Our sexy, lean mice who ate high-protein, low-carb diets were the shortest lived of all,” the scientists wrote in 2014. “They made great-looking middle-aged corpses.”

Dan Buettner, an author who identified five regions around the world where people have especially long life spans, said that a diet of predominantly whole food, plant-based meals, among other practices, is what leads to a long, healthy life.

“I know of no long-lived culture in the history of the world that were mainly meat eaters,” Mr. Buettner said by phone from Italy, where he was conducting further research on the places he has dubbed “blue zones.”

For some, going carnivore appears to be a facet of the optimization culture that seeks self-improvement through so-called bio hacking and other methods. For others, there may be an aspect of flexing one’s masculinity and success through the consumption of beefsteak, a luxury in much of the world. It is notable that online promoters almost exclusively post videos eating red meat, though fish is part of the diet.

Dr. Baker, who planned to eat a rib-eye steak and eight ounces of salmon for his main meal on the day he was interviewed, said he kept two freezers in his garage, which at that moment contained “half a side of beef from a local rancher.”

Rib-eye steak, even when eaten every day, “is viscerally and primitively satisfying to me,” he said. “I get to eat stuff that only royalty would have eaten through history.”

Dr. Baker, who runs a nutrition and lifestyle company and no longer practices medicine, said he usually recommended that people adopt the carnivore diet for a limited time to reset their digestive systems. After that, they may reintroduce other foods or stay carnivore as he has.

“If somebody wants to turn it into a lifestyle and call themselves Carnivore Carl, that’s up to them,” he said.

That people have embraced a way of eating referred to as “crazy” and “radical” even by its evangelists may say something about the Western diet of processed foods and its effect on the populace.

On this point, at least, Mr. Buettner can agree with the carnivores.

“We live in an environment where 95 out of 100 food decisions presented to us are bad,” he said. “So in desperation, to turn to an extreme diet, I don’t blame any overweight and unhealthy American.”