(AP) -- Carbs? Calories? Fat? They are so very last decade. Dieters and would-be healthy eaters know the nutrient of the moment being tallied, sought and bought is protein.
Spurred by trainers, diet gurus and weight-loss plans, Americans are seeking more- and more unique - sources of protein, from almonds ground into milk and soy reshaped as pasta, to peas and whey turned into powders and shakes. And food producers are happy to oblige.
Powders and energy bars packed with 20, 30 or even more grams of protein per serving are selling briskly. Supermarket shelves once crowded with foods boasting of being high in fiber or low in fat now are jammed with claims of protein content. Yet this is happening even as Americans eat less meat, the go-to source of protein for generations.
"People are getting smarter about foods in general," said Phil Lempert, a food marketing expert known as The Supermarket Guru. He sees higher meat prices driving people to other sources of protein, a movement that has becoming more pronounced this year.
"Longer term, I think you're going to see people starting to look at more vegetables and different combinations to create proteins like rice and beans."
Amanda Perry - an on-the-go mom with two jobs and a 1-year-old - is a good example. She counts on lots of protein to keep her feeling full and full of energy. But she needs it to be portable, so she often mixes protein powder with almond milk, maybe a banana and some peanut butter.
"It's easily portable, which I think is awesome for busy people because you're on the run," said Perry, a 31-year-old personal trainer who owns a gym in Chelmsford, Mass., with her husband. "You can't really take a chicken breast or a piece of steak with you if you're going to be out for several hours."
Red meat, a rich source of protein, is going through an especially bumpy run. Prices are up, and so are health concerns about beef and its saturated fat content. Americans are expected to consume about 15 percent less beef on a per capita basis this year compared to 2007, according to Steiner & Company, an economic consultant to the food industry. Per capita consumption of all red meat and poultry is expected to be down by 10 percent over the same period.
But if forces are pushing people away from meat, health conscious Americans are simultaneously being lured to other sources of protein, such as nuts, beans, soy and seafood.
Protein has had popularity peaks before - think of the Atkins diet craze not so many years ago - though this time there are a chorus of voices touting the benefits of protein-heavy regimens like the Paleo Diet, which stresses the lean meats and wild plants eaten by our ancestors. And it's being helped along by accumulating evidence that plant-based protein can lower cholesterol levels and have other beneficial effects.
A trip down the grocery aisle shows food makers are tuned in to this trend and happy to engage shoppers about it, from Yoplait Greek yogurts ("2X protein") to Boca meatless lasagna ("21 g protein") to Perdue chicken breast tenders ("excellent source of protein").
Like your protein concentrated? Analysts say sales are up for high-protein bars.
"As Americans are becoming more health conscious and busier, protein bar sales are increasing because they are a convenient way to gain protein on the go," said IBISWorld analyst Mary Nanfelt, adding that many protein bars are eaten after a workout to help the stressed-out muscles.
Also popular are the protein-rich powders, often made with whey, once associated mostly with weightlifters looking to bulk up. Perry said her protein powders - which are vegan because they sit in her stomach better - make her feel more energetic.
"I used to be afraid of it. And I have friends and clients who are sort of afraid of it. They think, `Oh, I'm going to gain too much weight, it's too many calories.' But what they don't know - and this is common for a lot of women - is that they're not getting enough calories, and they're not getting enough protein."
Actually, most Americans eat plenty of protein. The latest available federal survey of what Americans eat, which covers 2007-2008, shows both men and women commonly consuming more protein than needed, sometimes by a third or more.
Of course, the amount of protein needed varies by age, weight and activity level, though federal recommendations suggest 56 grams daily for a 154 pound man and 46 grams for a 126 pound woman. Those levels are not difficult to achieve if, say, you scramble eggs for breakfast, grab a couple of slices of pepperoni pizza for lunch and eat chicken and broccoli for dinner.
"There's this whole idea that I think a lot of people are plagued by that you have to get so much protein. And the truth is most of us do get enough protein and you don't have to have as much as you think," said Marisa Moore, an Atlanta-based dietitian and spokeswoman for the Academy of Nutrition and Dietetics.
People worried about protein might do better focusing on a healthy, diverse diet rather than counting grams.
Margaret McDowell, a nutritionist with the National Institutes of Health's Division of Nutrition Research Coordination, notes that lean meats and poultry, seafood and fat-free dairy products are all good ways to get protein.
"If you can consume your foods from a normal diet, that would be preferable because foods give a lot of other things beside protein and it's probably more tasty and enjoyable to eat a lean piece of grilled chicken," McDowell said. "I only eat protein bars if I'm desperate, if I'm running for a long time or need a quick snack."
Proteins from meat, poultry, fish, eggs, and milk are "complete," meaning they contain all the essential amino acids the body needs, while proteins in plants like beans and peas, grains, nuts, seeds, and soy are "incomplete" proteins because they lack in one or more of the essential amino acids. This is why a vegan diet takes a little bit more planning.
But McDowell said a vegan diet can provide adequate protein by including a variety of plant protein sources.
"I think most of us don't need a supplement," McDowell said.