Eating like a caveman is getting costlier.
That’s dour news for the growing number of Americans adopting diets that mimic the eating habits of their hunter- gatherer ancestors. The Bloomberg Protein Index, which tracks the prices of beef, beans, bacon and nine other protein sources, has jumped 28 percent in the five years through May. The measure has increased 5 percent this year, twice as fast as the gain for all food prices, as beef and pork got more expensive.
While more than half of American consumers are looking to eat more protein and millions are adhering to the Paleolithic, or Paleo, diet, the higher cost of the muscle-building amino acids threatens to curb their enthusiasm and send them in search of cheaper alternatives. That reversal may hurt foodmakers such as Kraft Foods Group Inc. and restaurant chains like Taco Bell that are advertising more protein-heavy fare.
"For people who wanted to add protein just because it’s healthy, if they start to get sticker shock, they might pull back a little bit," Darren Seifer, an analyst at researcher NPD Group Inc., said in an interview. Consumers may switch to smaller sizes or substitute cheaper options such as chicken for higher-priced sources like beef, he said.
The idea of high protein consumption as a key to staying fit was popularized in the 1960s with Irwin Stillman’s book "The Doctor’s Quick Weight Loss Diet." Robert Atkins followed in the 1970s and 1980s with diets designed to boost energy and drop pounds by limiting carbohydrates.
More recently in vogue is the Paleo diet, which encourages people to eat only whole, unprocessed foods like those available to humans in the Stone Age. About 1 million to 3 million Americans may have adopted the diet, according to an online study conducted by Hamilton Stapell, a professor at State University of New York at New Paltz.
Now, prices for some of the most common types of meat are surging this year. Pork has climbed as a virus killed as many as 8 million hogs, reducing supplies. Beef prices are up after years of drought shrank cattle herds to the smallest since 1951. Prices for eggs and dairy products also have gained in the past 12 months as export demand grows.
Not all customers are willing to pay the higher prices, said Panera Bread Co. Chief Concept Officer Scott Davis, who came up with the chain’s protein-rich egg-and-ham breakfast sandwich while dabbling in the Paleo diet.
Higher meat costs make it "a challenge to do more with protein today," he said.
Panera has a Power Menu that includes steak-and-egg breakfast bowls and Mediterranean roasted-turkey salads. The St. Louis-based company also recently added black bean and curried lentil flavors of hummus, made from protein-heavy chickpeas.
The high-protein salads and bowls are just about 20 cents more, on average, than regular salads because consumers would consider even an extra $1 a "hefty increase," Davis said. Panera shares fell 0.1 percent to $147.73 at 9:57 a.m. in New York.
Yum! Brands Inc.’s Taco Bell chain last year tested a Power Protein Menu with chicken and steak burritos and bowls -- each with at least 20 grams of protein and 450 calories or less. The items were literally beefed up with double portions of meat, as well as guacamole, corn and reduced-fat sour cream. While the chain previously had a low-calorie, low-fat menu, it no longer resonated with customers, said Melissa Friebe, the chain’s senior director of strategy and insights.
Customers said they wanted to "feel full without feeling weighed down," she said.
Foodmakers are also getting behind the trend. Kraft’s Oscar-Mayer introduced P3 Portable Protein Packs with meat, cheese and nuts earlier this year. There are four different versions -- ham, chicken and two kinds of turkey -- that have at least 13 grams of protein and 170 calories or less. Recent commercials tout the $1.79 packs as "back to basics" in a world filled with diet fads.
"It came down to keeping it simple," Joe Fragnito, the brand’s vice president of marketing, said in an interview. While the company had experimented with other high-protein foods, such as salads and empanadas, most people think of meat, cheese and nuts as "the original sources of protein."
Kellogg Co., facing declining cold cereal sales, plans to introduce two new Special K protein bars. It’s also trying to spur sales by pointing out the protein content in milk and cereals.
"Consumers are seeking protein," CEO John Bryant said on a conference call last month. "We’re talking about the benefits of protein that comes with cereal and milk, which is very much on track with the consumer today."
More than half of adults want more protein in their diets, according to a March study from Port Washington, New York-based NPD. The percent of adults who look for "protein" on nutrition labels rose to 24.9 percent in 2013, the highest since at least 2004, the study shows.
Consumers are experimenting more with non-meat protein, as well, in part to find cheaper sources of the nutrient, according to the study. Along with obvious choices such as yogurt, nuts and seeds, more are flocking to pea powders, quinoa and lentils.
The Bloomberg Protein Index includes prices for ground beef, eggs, whole milk, pork chops, whole chicken, sliced bacon, dried beans, cheddar cheese, sirloin steak, whole turkey, creamy peanut butter and ham from the U.S. Bureau of Labor Statistics. Beef, pork and ham have gained the most this year, while turkey, eggs and peanut butter prices have fallen.
An adult weighing 180 pounds needs about 54 grams of protein a day, while a 130-pound person should have 39 grams, according to the U.S. Department of Agriculture.
Eating more protein and fat can aid weight loss by making people feel better satiated and helping them avoid snacks, said Domingo Pinero, professor of nutrition and food studies at New York University. Dieters should proceed with caution as some can develop kidney or cardiovascular complications from too much protein, he said.
Almost all Americans, as long as they’re eating sufficient calories, are probably getting enough protein, Pinero said. About 35 percent of adults in the U.S. are considered obese, according to the Centers for Disease Control and Prevention.
"There’s no such thing as protein deficiency in this country," he said.