The Inside Scoop on How America Became Obsessed With Protein

And how much protein humans actually need.

Lais Borges/Inverse; Getty

America can’t get enough protein. From whey smoothies to protein-packed pancakes, pasta, and ice cream, the muscle-building macronutrient has become the guaranteed solution to all health ills.

“It’s this catchall,” Hannah Cutting-Jones, a food historian and director of food studies at the University of Oregon, tells Inverse. Want to gain muscle? Eat more protein. Lose weight? Focus on protein. Everybody, from your dog to your grandparents, needs more protein. But do they, really?

In the last several decades, we have, on average, consistently eaten more of this macronutrient than the daily recommended amounts set by health organizations. This is despite the fact that these groups have continued to decrease the recommended amount of protein we need per day. To complicate matters, we still haven’t settled on the ideal amount of protein necessary for a healthy diet. All of this combined has left protein — the one macronutrient yet to be demonized by the diet industry — in a scientific and cultural gray area. And it begs the question: How much protein do we actually need?

The Only Macronutrient Left Standing

Part of the protein gold rush stems from decades of whittling down our diet in search of the best foods. Over the years, popular diets, like Atkins and keto, have demonized carbohydrates while others, like the Ornish diet, vilified fats. With carbs and fats condemned, protein became the only nutrient deemed OK to eat in whatever quantity desired while still maintaining good health.

“It’s the only macronutrient left standing,” Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute at Tufts University. “In people’s minds, there’s nothing left.” But a macronutrient, Mozaffarian says, is not the same thing as a food. “That’s like saying a fat food or a carb food. Most foods are composed of multiple macronutrients.”

We can trace our impulse to atomize our food to what Mozaffarian calls “the birth of modern nutrition science,” which is when we first discovered vitamins and began seeing foods as their components rather than the sum of their parts. Though protein’s discovery predates this moment by a century, once we realized certain vitamins could cure disease, we latched onto these discrete compounds. This was also back when many deficiency-induced diseases like scurvy, rickets, beriberi, and pellagra were common, says Mozaffarian.

The experts Inverse spoke to for this story all agree that marketing has also been key to protein’s success. One estimate from 2022 valued the global sports nutrition and supplements market at $27 billion, which often emphasizes protein consumption, among other nutrients. By 2030, it is projected to exceed $37 billion.

“The idea of good health and protein consumption have become fused.”

“Because protein lives so visibly in our cultural memory as being important, I think it’s an easy target to market,” says David Seres, a professor of medicine at Columbia University Medical Center’s Institute of Human Nutrition.

“Most of us, if we’re getting enough calories, [we’re] probably [getting] enough protein,” Cutting-Jones says. “We probably don’t need to stress about it as much as we do. I think a lot of it is a moneymaker.” One famous protein marketing technique, she says, was rebranding pork as “the other white meat” in light of red meat’s link to chronic disease in the mid-1900s.

“The idea of good health and protein consumption have become fused,” Cutting-Jones says. The words “high in protein” now routinely appear on foods that aren’t even supposed to be high in protein, like cereal. When a food advertises its protein-richness, consumers are more likely to make other positive assumptions about it. For example, a 2024 study in the journal Foods describes how over 1,000 participants perceived a protein-fortified version of a cereal as healthier and more likely to build muscle than its original counterpart. They also seemed to disregard that the protein-fortified cereal had more sugar, sodium, and calories than the original one.

We Are Eating More Protein Than Ever

Protein recommendations first came about in 1877 when German physiologist Carl von Voit published his book An Investigation of Diet in Public Institutions. Von Voit had been studying nutritional needs of working class German men, and concluded that 118 grams of protein was optimal. This figure became known as the Voit standard. But American chemist Russell Henry Chittenden at Yale University used himself as a test subject to refute this recommendation. In 1904, he published in the journal Physiological Economy in Nutrition that we needed just 50 grams of protein daily.

During the Second World War, in 1941, then-President Franklin Roosevelt called the National Nutrition Conference for Defense to publish the first recommended daily protein allowances for Americans. Many men drafted into war weren’t healthy, which prompted this focus on nutrition, says Cutting-Jones. The group recommended 1 gram of protein per kilogram of body weight, which comes out to about 60 grams for women and 70 for men.

Now, the Food and Drug Administration recommends we eat 50 grams, what Russell Henry Chittenden originally concluded, of protein daily. But in the decades since these recommendations appeared, Americans are eating more than ever before, Cutting-Jones says.

In March 2023, the USDA Economic Research Service published a report on dietary quality by food source and demographics that looked at the years between 1977 and 2018. This report analyzed data on the diets of thousands of Americans aged 2 years and older. It found that men consistently eat more protein than women, and people with high incomes eat more protein than people with middle or low incomes. By age and sex, 2005 and 2006 boasted the highest protein intake. This high point is in line with the timeline Cutting-Jones describes, saying that by the early 2000s, protein had emerged as a full-fledged panacea.

This data isn’t a perfect reflection of protein consumption. For one, the sample size shrinks over time. The researchers go from analyzing the habits of over 41,000 people in 1977, to fewer than 10,000 in 2003, and by 2018 are looking at just over 7,100 people.

How Much Protein Do We Really Need?

Experts still don’t agree on how much protein we should eat. Part of this conundrum comes from the flaws in scientific research on nutrition. Much of our modern dietary guidance also comes from observational studies, says Columbia’s David Seres. Rather than closely monitoring two identical scenarios to track the effects of one variable, observational studies analyze swaths of data over time and find correlations. While researchers can make associations between factors, Seres says, it’s much harder to establish cause and effect.

Seres says it’s “almost impossible” to create a randomized double-blind trial — the gold standard for clinical research — for nutrition. It would be difficult and expensive to create a trial involving thousands of people who agree to eat a particular way with no deviation. “Think about how many times you’ve tried to stick to a diet,” he says.

We do know that eating more protein than we need means “it turns to fat,” says Mozaffarian. But instead of going straight to adipose tissue like fat typically does, extra protein goes through the liver, where it’s converted to fat through a process called de novo lipogenesis. This type of fat typically pads the organs, he says, and has been linked to an increased risk of metabolic syndrome and heart disease. And while a high-protein, low-carb diet may seem enticing, Mozaffarian says that excess protein still raises the risk of diabetes even though it doesn’t raise blood sugar as excess amino acids can affect insulin signaling.

A 2024 study from the University of Pittsburgh concluded that consuming over 22 percent of your calories from protein can lead to increased activation of immune cells called monocytes that play a role in plaque formation. The authors analyzed blood samples from participants after they drank high- or low-protein shakes. They searched for monocyte circulation between one and four hours after participants drank the shake, and found that meals with more than 25 grams of protein induce this process that helps create plaque, which can increase the risk of heart disease.

Since the researchers looked for an increase in cells associated with plaque rather than an increase in plaque itself, Seres is unsure how much we can generalize this data. Still, he calls these results “certainly concerning.”

What Type of Protein is Best?

Protein is made up of organic compounds called amino acids. Of the 20 amino acids we need, nine are essential to our diet, meaning we cannot synthesize them ourselves. But even if we don’t eat meals perfectly balanced in these 9 amino acids our bodies are adept at extracting the nutrients we need, Cutting-Jones says. Seres says research corroborates this idea: “There’s good consensus that if you don’t happen to get enough amino acids in any given meal, it balances out over time.”

But just because something has a lot of protein doesn’t always make it the best choice. Certain packaged foods, especially ultra-processed ones, boast high protein counts, but Seres and Cutting-Jones emphasize that these products often contain added protein. They say that eating diverse proteins from whole foods is healthier than eating a high-quantity of protein isolate that’s been added to packaged foods.

“Somebody discovered if you put it in a nice package, you can sell it to all the sports people as a great supplement.”

Malcolm Watford, a professor of nutritional sciences at Rutgers University School of Environmental and Biological Sciences, says that Americans’ consumption of protein can be broken down into high-quality protein and high-quantity protein. High-quantity proteins have many grams of protein, but high-quality proteins have many different amino acids, even if they have less protein overall. Watford favors high-quality protein over high-quantity, as do most nutrition experts.

But protein has spent the past 50 or so years solidifying itself in the high-quantity bucket, and it could take a monumental effort to scoop our way out of it. Watford recalls a time 40 years ago when he first came to the United States from the United Kingdom and seeing Wisconsin dairy farmers giving away whey protein to pig farmers for free.

“Somebody discovered if you put it in a nice package, you can sell it to all the sports people as a great supplement.”

Related Tags