How Long Have Americans Been Focused on Protein?

From shakes and bars to everyday foods and drinks, protein products are everywhere—but enthusiasm for the macronutrient was decades in the making.

In the mid-1800s, German chemist Justus von Liebig regarded protein as “the only true nutrient” due to its vital role in tissue building and muscle growth. The focus on protein took off as nutritional research expanded during World War II, and its popularity skyrocketed in the 1990s and early 2000s, fueled by fitness culture and high-protein, low-carb diet fads.

“One of the reasons that we’ve been so obsessed with protein is that it has never been vilified in the same way that carbs and fats have been,” says Hannah Cutting-Jones, a food historian and assistant professor of global studies at the University of Oregon. “It has always been on this pedestal.” 

Here’s how protein became a multibillion-dollar industry in the United States.

Enthusiasm for protein dates back to the mid-1800s, when scientists first determined its chemical properties and identified carbohydrates, fats and proteins as the main macronutrients that provide the body with energy. Protein was lauded for its nitrogen-rich composition—an essential building block for human development.

In the 1860s, Liebig mass-produced one of the first protein-enriched products. His meat extract was sold worldwide, primarily in Europe, as an inexpensive alternative to animal meat. By the century’s end, the U.S. Department of Agriculture, founded in 1862, recommended more than 110 grams of protein a day for working men—a figure that was later substantially reduced.

“This was the same time as urbanization,” Cutting-Jones says. “Really, the focus was, how can working people afford to eat meat, which was the main conduit of protein?”

Even amid the pervasive view that “meat makes meat,” scientists recognized that certain plant-based foods provided at least some protein. Around the turn of the century, controversial nutritionist (and staunch vegetarian) John Harvey Kellogg and his family began mass-producing and distributing various meat substitutes made from nuts and wheat—along with their widely successful Kellogg breakfast cereals.

Nutrition science and research really took off during and after World War II, partly fueled by the need for healthy soldiers and a physically weakened male population following the Great Depression. In 1943, the U.S. government released the country’s first comprehensive Recommended Dietary Allowances for protein, calories and vitamins for adults and children, recommending roughly 0.8 to 1 gram per kilogram of body weight for most adults—a figure that has since changed little.

According to Cutting-Jones, for most of the 1900s, eating more protein than recommended was limited mainly to working men and athletes. “[Protein] was not really linked yet to weight loss,” Cutting-Jones says. “It was very much a niche market for a long time.”

The first precursor to the modern protein shake hit the market in 1952, with bodybuilder Bob Hoffman’s Hi-Proteen powder made from soy protein, whey and flavorings. That same decade, the United Nations publicly identified protein deficiency as a major nutritional problem in developing countries. The “protein gap” myth (which U.S. farmers hoped to fill by distributing powdered milk products) was largely debunked in the 1970s but generated widespread attention.

As studies increasingly linked saturated fats and sugars to heart disease, protein products remained visible but Americans focused more on low-calorie, low-fat diets as products like SlimFast and Diet Coke hit the market.

Some nutritionists, including cardiologist Robert Atkins, introduced high-protein weight-loss programs in the 1970s. Atkins’s 1972 book recommended a diet that restricted carbs and upped protein and fat intake, though its popularity didn’t peak until the early 2000s. In 1977, Dr. Robert Linn published a "protein-sparing fast program” that promoted the use of a low-calorie, liquid protein supplement. The regimen was later the subject of federal investigation following the deaths of numerous people adhering to the diet.

Protein powders and supplements became mainstream by the late 1980s and early 1990s with the rise of bodybuilding and fitness culture. “All you had to do was go into a health food store and look at the protein supplements—enormous cans of Whey protein,” says Marion Nestle, professor emerita of nutrition, food studies and public health at New York University. Whey, derived from cow’s milk, remains a fitness industry staple.

Another turning point for protein came in the early 2000s, when scientific studies suggested that high-protein diets could help people lose weight. “It opens up this entire realm of marketing for protein products, where it just goes wild at that point,” Cutting-Jones says. 

Protein was now the leading nutrient among women and men seeking trimmer waistlines, older adults looking to maintain muscle mass, and children and adolescents, Cutting-Jones says. Enthusiasm for high-protein, low-carb diets persisted, even after a 2003 study in The New England Journal of Medicine cautioned that more research was needed to determine their long-term safety.

In 2007, the World Health Organization recommended a daily minimum of 0.83 grams of protein per kilogram of body weight for most sedentary adults—similar to the dietary allowance of 0.8 grams per kilogram in place in the United States.

By 2024, the protein supplements market was valued at $9.88 billion in the United States and $28.15 billion globally, according to Fortune Business Insights. In an era of fitness influencers and GLP-1 weight-loss drugs, experts say most Americans meet or exceed their daily protein needs. 

High-protein foods and drinks, ranging from popcorn to coffee, are now ubiquitous in the United States and around the world.

“To me, it’s a marketing issue, a fitness issue, a positive message that has an aura of health,” Nestle says. “And it sells like mad.”