In late August 2024, the physician and longevity guru Peter Attia posted a new reel for his 1.3 million Instagram followers, featuring a close-up of a stack of golden boxes, each about the size of a hardcover book, piled up on a marble countertop. The image stood out; Mr. Attia’s grid consists mostly of snippets from his popular podcast, The Drive, and straight-to-camera clips of him sharing advice on topics like zone 2 cardio training or the importance of getting regular colonoscopies.

“Pretty awesome day in the Attia household,” he said from behind the camera. “Just received, yesterday, the first official shipment of the new David bar.”

These protein bars would become available to the public in a few weeks, Mr. Attia explained, and the teenagers in his home — a demographic not known to be obsessed with optimal nutrition — had been devouring his supply. “I think these are just awesome, and I am really excited for people to start trying these things,” he said.

The David bar, created by the RXBar co-founder Peter Rahal and a Keto cookie entrepreneur named Zach Ranen, was diving into a marketplace already up to its eyeballs in protein. In recent years, protein supplementation has crossed the species barrier from fitness-coded products like bars into everyday foods. Today’s supermarkets offer high-protein frozen waffles, breakfast cereals, popcorn, pastas, ice cream — even protein-enhanced soda and candy. According to the market research firm Mintel, the number of food and beverage products coming to market with a high protein claim quadrupled between 2013 and 2024.

The protein maximizer can now begin her day with a Legendary Foods Brown Sugar Cinnamon Breakfast Pastry (20 grams of protein), move on to Immi’s pea protein-based instant ramen for lunch (24 grams), snack on Wilde chips made from chicken and egg white (10 grams), and microwave a Vital Pursuit high-protein frozen pepperoni pizza (22 grams) for dinner — all, to borrow Michael Pollan’s aphorism, without eating anything her great-grandmother would have recognized as food.

But for the protein-obsessed, the bar still reigns supreme. The category-leading protein bar, Quest, tops out at 21 grams of protein for 180 calories: almost as much protein as a McDonald’s Big Mac, for less than half the calories. “We knew we could do more,” Mr. Rahal said recently, during a visit to the brand’s offices in Manhattan. “The question is, what’s the upper limit?”

The David bar was their answer: 28 grams of protein, 150 calories, and zero sugar, basically a protein Scud missile wrapped in gold foil. The protein-to-calorie ratio approaches that of boiled cod.

But just as important to David Protein’s launch was its canny marketing. Its name is a reference to Michelangelo’s sculpture of the idealized male form, the image of which has featured heavily in the bar’s marketing. Mr. Attia and Andrew Huberman, another influential voice in the self-optimization space, are both David investors, and by association, pitchmen. Mr. Attia, who was not directly involved in formulating the bars, is also the brand’s chief science officer.

Adding to Mr. Attia’s hype, the brand sent out 20,000 product samples last August as a teaser, leading to a TikTok frenzy of fitness influencers brandishing the bar, gleefully reciting its protein content, and tasting it on camera. David began its first official day of sales on Sept. 16, with 40,000 customers on the waiting list. The company moved more than $1 million worth of bars in a week, and is on track to hit $180 million in sales this year, largely through its own site, Amazon and TikTok Shop. Retailers like Vitamin Shoppe and Wegman’s recently began stocking the bars; Kroger, Walmart and Target are in the pipeline.

In May, after nine months in business, David announced that it had raised $75 million in Series A funding, at a $725 million valuation. Investors are betting that today’s obsession with protein maxing isn’t simply the latest health fad, but represents a long-term dietary shift — one facet of our growing cultural embrace of optimization at every turn.

Mr. Rahal and Mr. Ranen believe they can outlast David’s viral moment and build it into a lasting brand synonymous with everybody’s favorite macronutrient. Bars, they say, are just the beginning. And they have already shown they’ll do whatever it takes to muscle out other competitors.

Nutrition experts are less sure that we need so much protein. So: can the protein craze last?

From Unprocessed to High Protein

Even before its exact function was understood, protein was known to be important for building muscle strength; soldiers and laborers were historically encouraged to eat meat-heavy diets. But until relatively recently, there was little worry about the average American getting enough of the stuff, said Lourdes Castro, a registered dietitian and adjunct professor of nutrition at New York University, and the director of N.Y.U.’s Food Lab. Beginning in the 1950s, whey proteins isolated from milk began to be used in protein powders as a dietary supplement, but the use of those was limited to the relatively niche sport of bodybuilding.

Liz Applegate, a former director of sports nutrition at the University of California Davis who began teaching nutrition at the school in 1985, says that she first saw protein bars and shakes break into the mainstream in the late 1990s. Bodybuilding, and physical fitness in general, was expanding into a mass hobby, but also, crucially, protein began to be understood as a powerful tool for weight reduction.

“That was the breakthrough,” Dr. Applegate said. “The idea that we could treat obesity with a high-protein diet.”

Weight-loss regimens like Dr. Atkins’ Diet Revolution, the Protein Power diet and the South Beach diet dispensed with the calorie restriction or low-fat focus that had been a staple of previous fad diets, and instead centered on the idea of consuming high levels of protein while strictly limiting carbohydrates.

By the time Mr. Rahal came up with the RXBar, in 2013, nutrition culture had moved on from the Atkins craze to the likes of Paleo and Whole30 — regimens that continued to restrict carbohydrates, but also called for consuming whole, minimally processed foods.

Mr. Rahal, then in his 20s and working in transportation logistics, noticed that the energy bars offered for sale at his CrossFit gym were gathering dust on the shelf. CrossFitters tended to adhere to a Paleo diet, and the ultraprocessed energy bars of the day didn’t fit in. He and a friend, Jared Smith, each stumped up $5,000 and started spending their weekends making Paleo-compliant bars from dates, egg whites and nuts in Mr. Rahal’s mother’s basement, and selling them at CrossFit gyms.

Less than five years later, they sold RXBar to Kellogg’s for $600 million.

Mr. Rahal collected his winnings, bought a Ferrari and a $19 million beachfront mansion in Miami, “tried hedonism for a little bit,” and began to dabble in investing. It wasn’t as fun as it sounds. “I was not in the game,” Mr. Rahal said.

He found a business partner — Mr. Ranen, a finance-savvy nutrition obsessive — and in September 2023, they got to work, once again mining the nutrition zeitgeist to come up with their concept. They were focused on protein from the start.

At RXBar, the goal had been to create the highest-protein bar possible within the constraints of using only natural foods, and zero additives. Mr. Rahal and Mr. Smith hit 12 grams; a respectable number by the standards of the day. But Mr. Rahal said that by the time he left Kellogg’s, in 2019, this approach wasn’t cutting it. “I saw all our customers move away to other things,” he said. The Paleo crowd had progressed to Keto or carnivore diets, which took even harder-line stances against carbohydrates. (According to a spokesperson for Kellanova, as the corporate entity is now known, RXBar remains one of the fastest-growing bars in the “healthy snack bar” category.)

Even outside the bar category, consumers were clamoring for more protein. Sales of cottage cheese were increasing by double digits each year. Greek-style yogurt brands like Danone’s Oikos and Chobani that had already benefited from the protein craze were developing even higher protein formulations. Investors couldn’t get enough, either. The grain-free, protein-loaded cereal start-up Magic Spoon has raised more than $100 million in funding to date. Coca-Cola has invested some $7 billion in Fairlife, the maker of high-protein milk and milk-based protein shakes.

“When you look at the rise in protein launches in more processed foods, it’s cheaper, it’s more convenient, it’s easier than traditional protein sources” like meat and eggs, explained Julia Mills, Mintel’s U.S. food and drink analyst. Even amid the current backlash against ultraprocessed foods, items with added protein seem to get a pass.

The Key Ingredient

Although the David brand is all about protein, the bar’s major innovation has to do with fat.

In place of the plant oils typically used in bars, David uses a substance known as E.P.G., or esterified propoxylated glycerol. E.P.G. is a modified plant fat that moves through your digestive system mostly undigested, delivering 92 percent fewer calories compared with traditional fats.

E.P.G. was developed in the 1990s, but is still today a niche ingredient, in use by a handful of relatively small food companies globally, and manufactured by one called Epogee. Mr. Ranen first came across it several years ago in a low-calorie ice cream he likes to eat, made by a Swedish company called Nick’s, and thought it would be a useful tool for accomplishing David’s aggressive calorie reduction target: The market-leading protein bars derive 40 to 50 percent of their calories from protein. David was shooting for 75.

Epogee’s modest capacity to produce E.P.G. has become the choke point in David’s ability to scale up bar production to meet demand; the bar is currently out of stock on the company’s website in all eight flavors, though it is available for the time being via the company’s other retail partners.

In May, David made a tactical move in the protein arms race, announcing that it would use an undisclosed portion of its new funding to acquire Epogee, thus controlling the supply of E.P.G. David is increasing production, and at least in the short term, has stopped supplying E.P.G. to other customers while it sees to its own needs — a decision that seems to have been viewed as an outright act of aggression by some of Epogee’s other current customers, who immediately filed suit.

OWN Your Hunger, Lighten Up Foods, and Defiant Foods claimed that David violated federal antitrust laws by creating an artificial monopoly, restricting access to E.P.G., to which Epogee holds the patent rights. David shot back with court papers denying any wrongdoing. Mr. Rahal said in an interview that customers who find themselves out of luck should have had long-term commercial agreements in place to avoid this scenario.

Ruz Safai, founder and chief executive of OWN Your Hunger, said that Epogee never informed OWN that supply agreements were available or necessary, nor offered any terms such as minimum order quantities, advance purchase commitments, or pooled ordering arrangements before the acquisition. “Had they done so, OWN would have readily participated to meet volume requirements,” Mr. Safai said.

Once E.P.G. production is up to speed, Mr. Rahal said that David plans for Epogee to resume selling the ingredient to other food companies — though not, he said, to a customer with a directly competitive product.

A QVC Vibe

Hitting one’s protein goal has come to inspire an entire genre of social media content. From “30 gram protein breakfast” Instagram Reels to “what I eat in a day to stay lean and toned” TikToks and explainers on the nuances of protein quality, there’s no end to the protein propaganda one might encounter after pausing for a moment too long on a recipe video for a chocolate lava cake with 42 grams of protein. It’s not all coming from fitness obsessives, either; online, getting enough protein has become a mainstream nugget of self-help advice, on par with strategies for getting more restful sleep.

This is the hype machine into which David plugged itself when it launched last September. The product itself seems built for generating viral attention. Its branding comes courtesy of Day Job, the creative studio behind cool-kid products like Fly by Jing chili crisp and Recess CBD sodas; David, with its gilded packaging, formal serif font (inspired by the typography in 1990s Apple ads), and allusions to Renaissance sculpture, reads more like an aspirational luxury product than a mere snack bar. “The thing we were looking for is, how do you make this an object that people feel OK being seen holding?,” Rion Harmon, Day Job’s co-founder, explained of the branding process. “How can we make it feel like athleisure?”

That brand positioning is evident on its artfully curated Instagram feed. But David’s main engine of growth has been TikTok, where a chaotic carnival vibe reigns. “I’ve never seen a brand so intensely launch on TikTok Shop,” said Rachel Karten, a social media consultant who writes the newsletter Link In Bio. David has leaned into hosting frequent QVC-style live selling events on the platform and has an army of affiliates hawking its bars. One guy in a tank top mashes two Blueberry Pie-flavored David bars into his mouth at once while talking about their unbelievable nutritional profile; many others hold David boxes up to the camera and shout about crazy, incredible, limited-time-only sales.

Ms. Karten said it’s an unusual strategy for a company that has invested so much thought and effort into branding. “I was skeptical of that at first — why are they letting people go ham on their brand on TikTok Shop?,” Ms. Karten said. But “when I saw bodegas putting ‘As Seen on TikTok’ signs next to their David bars, I thought, ‘It’s working’.”

Sales of the flagship bar continue to chug along. David is now at work on a more mass-market “candy bar-like” product designed for “protein newbies” — think the GLP-1 drug user who has been instructed by their doctor to prioritize protein, a rapidly growing demographic that Mr. Ranen views as an important one to David’s long-term success.

On a recent Wednesday afternoon, I visited David’s research and development lab, tucked away behind a corral of standing desks in a building near Penn Station, to see the brand’s next product line in development. There, in a saucepan set on an induction burner, a food developer whisked gelatin into water, along with gums, maltitol, glycerin, allulose, zero-calorie sweeteners and flavorings, whipping it all into a frothy syrup. Inside the bowl of a KitchenAid mixer, the syrup was blended with protein powders. After a few minutes, a glossy, taffy-like white dough emerged. It was shaped and cut into rectangles, spread with gooey caramel-flavored fondant, topped with crispies, and then enrobed in melted chocolate custom-made for David using E.P.G. and artificial sweetener — a far cry from RXBar’s six whole-food ingredients.

The result was a bar that recalls the soft, springy texture of a marshmallow, or a Three Musketeers — or, more to the point, a less gummy version of the Built Puff, a popular bar sold by one of David’s main competitors. At 20 grams of protein and 150 calories, it’s almost entirely free from the chemical bitterness that tends to haunt protein bars (including the gold bar). David aims to begin selling the new item, the bronze bar, this fall.

Can It Last?

The protein trend shows no signs of slowing down. A recent report by Cargill found that 61 percent of Americans increased their protein intake in 2024; sales of protein drinks, powders, and supplements grew 18 percent that year, according to data from Circana data. New protein plays continue to appear on grocery shelves. Recently, a landing page popped up online teasing a new high-protein, creatine-enhanced, no-added-sugar product called Man Cereal (the newsletter Snaxshot reported that Day Job did the branding).

Whether all the extra protein is necessary is currently a matter of pitched debate in the nutrition world. Federal dietary guidelines recommend 0.8 grams per kilogram of body weight per day, which works out to 72 grams for a 200-pound man — two and a half David gold bars.

Ms. Castro of N.Y.U. points out that many consumers gravitating toward high-protein products today may not be using them to hit specific protein goals, but giving themselves permission to eat chips or cookies instead of a healthier whole food. Ms. Castro calls this the “healthy halo effect” — the idea that any food, if it contains protein, is automatically a good choice, whether or not it contributes any other nutritional benefits.

“I think, over time, people might realize that getting nutrients in these little packages is not as good as getting them in whole foods,” she said. “The healthy halo might wear off.”

Ms. Mills, the analyst at Mintel, isn’t so sure. There are still new protein horizons: According to her company’s data, products making protein claims have been on the rise since 2000. While the pace of new product releases is finally decreasing when it comes to foods, it’s still ramping up in beverages.

At a recent trade show, Ms. Mills said, she saw a panel of judges select protein-enhanced water as one of their favorite innovations on display. Starbucks is testing banana-flavored protein foam that can top off your coffee with 15 grams.

And as for David, as a measure of the company’s devotion to protein efficiency, they recently began selling packages of wild-caught Pacific Cod for $55. It’s a move that has all the trappings of a viral marketing stunt, but Mr. Rahal insists is a sincere product extension. Who among us can really tell the difference?