Protein: How Much Is Enough?

Here's everything you need to know about protein, one of the most important parts of every diet.

July 25, 2018
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Protein helps you slim down. Protein causes kidney stones. Protein gets you jacked. Protein gives you cancer. Protein makes your hair beautiful. Protein will renew your energy—until it snuffs out your life like a small flame smothered by a juicy, 16-ounce T-bone steak.

Confused? That’s entirely reasonable. The thing is, nutritional information is confusing. At different times, you’ve probably heard some variation of every single one of the above health claims.

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How can you sort out the truth? It’s tough—like trimming off that last piece of gristle—but it can be done.

So, protein. Let’s talk basics.

Protein is the macronutrient needed to build and repair tissues (like muscle), maintain healthy bones, and keep your body processes running smoothly. (Macronutrients are the nutrients our bodies require a lot of, and there are two more of them: fats and carbohydrates.) Protein also provides the body with energy (calories) and micronutrients (vitamins and minerals).

Most of the body’s protein is in the form of muscle protein. Muscles make up about half your body weight.

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The most concentrated sources of protein are meat and dairy products, but you can also find it in nuts, seeds, legumes, grains, vegetables, and soy products.

What are the benefits of protein?

In addition to building and maintaining your body, this macronutrient helps reduce your hunger levels and overall caloric intake. In a 2014 study published in Nutrition Journal, researchers compared afternoon snacks of high-protein yogurt, high-fat crackers, and high-fat chocolate. Study subjects were healthy women around the age of 27. The women who ate the high-protein yogurt felt less hungry in the afternoon than those who ate the chocolate. The yogurt-consuming group also ate less for dinner than those who ate chocolate or crackers.

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Upping protein also helps combat the effects of aging. According to a meta-analysis published earlier this year, added dietary protein significantly improved muscle strength and size in healthy people doing resistance exercise training, and older adults were especially in need of higher protein diets to see these changes. The data came from 1,863 participants in 49 studies, each a randomized controlled trial lasting no shorter than six weeks.

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“People often lose function as they get older. Not because they’re just old—it’s because they’ve decreased physical activity, decreased the physical and nutritional efforts required to support muscle development or retention, and this accelerates a variety of processes that increases overall muscle loss,” Matt Stranberg, registered dietitian nutritionist, licensed dietitian nutritionist, and certified strength and conditioning specialist, tells HealthyWay.

“Eating more high-quality protein, eating sufficient calories, and engaging in weightlifting or some form of external resistance helps people maintain their bones and muscle mass so they don’t run into nasty situations, like dangerous falls, bone disorders, bone breaks, and decreased overall quality of life,” he says.

How much protein do you need?

Some corners of the internet would have you believe your evenings must be spent scarfing down protein shakes and whole chicken breasts while drinking from a gallon jug of water in order to achieve protein goals, but this is not the case.

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According to Samantha Scruggs, a registered dietitian and licensed dietitian and nutritionist, “We see a pop culture phenomenon encouraging the intake of huge amounts of protein in the diet, which can be helpful in certain situations … but it is not necessary to eat that much protein.”

“The … Dietary Reference Intakes [recommended amount of protein] for adults is about 46 grams per day for women ages 14 to 70 years, and 52 to 56 grams per day for men of the same age range,” says Becky Kerkenbush, a registered dietitian. “Pregnant and lactating women need more—about 71 grams per day.”

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But more and more evidence suggests that the federal guidelines for protein intake, while sufficient, are not optimal, specifically for active or aging adults.

Stranberg, who works in an outpatient treatment program for athletes, notes that there’s a range. “The research literature usually states that the upper limit is 0.8 grams [of dietary protein] per pound [of body weight], or two grams per kilogram. That’s typically where most researchers agree is the optimal upper-limit amount, and that anything more than that is not necessarily required and could have negative effects, such as displacing carbohydrates and fats required to fuel performance,” he says.

However, he adds, “Some research and a lot of practitioners have seen benefits from 2.2 grams per kilogram, which is a gram per pound, and some amounts greater than this in hypocaloric [calorie-deficit] situations. Amounts greater than 0.8 grams [per] pound are thus worth exploring for some individuals interested in experimenting with higher protein protocols.”

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Context is crucial. “If you are exercising regularly, if you’re engaging in sports, if you are old, or if you’re recovering from an injury, or you are experiencing a disease, you’re probably going to need more than the RDA [Recommended Dietary Allowance],” says Stranberg.

Another time to aim for the upper end of the protein spectrum is when you’re trying to lose weight. “So there’s maintenance calorie intake; there’s hypocaloric, which is a deficit; hypercaloric, which is above your maintenance. If you eat maintenance or hypercaloric, it decreases protein needs, and the more hypocaloric you are—meaning the more calorie-deficit you are—the higher the protein needs become,” says Stranberg.

“The purpose of a calorie deficit, ideally, is to maintain muscle mass, minimize muscle loss, and maximize fat loss,” he says, “Higher protein intake, in this context, often decreases chances of muscle loss, increases calorie expenditure from thermic effects, and promotes much needed satiety during a deficit.” Dropping pounds will inevitably lead to some muscle loss, but eating extra protein helps you hold on to as much of that precious tissue as possible.

What is a protein deficiency?

There are two types of extreme protein deficiency. Marasmus, from the Greek term meaning to wither, is a deficiency of both protein and calories in one’s diet and is characterized by an emaciated look. Kwashiorkor—a word from the Kwa languages of coastal Ghana—is a deficiency in protein without a deficit in calories, characterized by a bloated appearance. These severe cases are most common in countries without access to protein-rich foods; in the United States, they’re rarer and are concentrated in poorer areas and hospital settings.

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Keith-Thomas Ayoob, registered dietitian, Fellow of the Academy of Nutrition and Dietetics, and associate clinical professor emeritus of the Department of Pediatrics at the Albert Einstein College of Medicine, says some populations might experience protein deficiencies at higher rates than others.

Deficiencies may show up on either side of the age spectrum. Teens, who are notorious breakfast skippers, are more likely to lack in the protein department, and seniors, too, as the variety of health problems and medicine they take may affect their appetites. (Medications that can cause a loss of appetite include those that treat cancer, depression, type 2 diabetes, Alzheimer’s, ulcerative colitis, Crohn’s disease, and attention deficit disorder.)

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Deficiencies can also occur in cases of disordered eating, eating disorders, and fad diets. “Every single month, there’s some celebrity—people are like, ‘How’d you lose weight? How did you do it?’ And they’re like, ‘Oh, I’m following my grapefruit diet, where I just abuse amphetamines all day long and then have a grapefruit for dinner!’” says Stranberg. “These juice cleanses and raw vegans and faddish diets, [they] can significantly increase risk for deficiencies and not getting enough protein to support your needs.”

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When it comes to feeding your body, there is no magic bullet. “You can’t neglect the fundamentals of nutrition: You need proteins, carbs, fats, macronutrients and micronutrients, and enough overall calories to support your body,” says Stranberg. “Failure to do so will cause severe consequences.”

How should we be eating protein?

To meet your needs, focus on a variety of high-quality proteins. Be sure not to try and cram it all in at once.

“Your body cannot use much more than about 30 to 35 grams of protein at a particular meal, so it needs protein throughout the day, not just a big blast at dinner,” says Ayoob. “Excess protein at a meal will just be used to burn calories or be stored as fat for the future.”

Some people have trouble with the heaviness of protein. Dairy foods like milk, Greek yogurt, cheese, and eggs, Ayoob says, are easy to chew, economical, suitable for breakfast, easily tolerated, and overall, the highest-quality proteins around.

Healthy high-protein options include:

  • Lean ground beef—“Lean beef is loaded with iron, which dairy foods do not have. Beef also doesn’t have to take long to cook either, depending on the cut,” says Ayoob. It can offer around 23 grams of protein per three-ounce serving.
  • Turkey breast—You can try it in tacos as a flavorful substitute for ground beef, and it boasts similar numbers for the amount of protein per serving.
  • Tuna—Yellowfin tuna in particular has some of the highest protein content of any seafood with 25 grams per three-ounce serving.
  • Pork chops—Add a side of applesauce to make a meal that feels like the comfort food of your childhood (with 23 grams per three ounces to boot!).
  • Tofu—The vegetarian staple offers a solid 10 grams of protein per half cup and is easy to bake or fry to perfection.
  • Lentils—With 18 grams in every cup, lentils are a cheap and plentiful supply for protein.
  • Greek yogurt—Every three ounces comes with about 8.5 grams of protein; it’s perfect as part of a veggie dip or as a sour cream substitute.
  • Milk—Both cow’s milk and soy milk (each eight grams per cup) are great options for easy-to-consume protein.

“I don’t think anyone would say that the red meat from KFC or McDonald’s is equivalent to a grass-fed steak that you buy at Whole Foods,” Stranberg points out.

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“The reason why people have problems when they eat a lot of meat in the United States is not necessarily because of very specific foods, but rather because they’re eating out of balance, deriving protein from a lot of meat that’s also high in sodium, high in additives, high in saturated fat, and not eating any fruits or vegetables or whole grains or anything to balance that out. When individuals choose high-quality protein sources, in addition to eating a well-balanced, micronutrient-rich diet, potential consequences regarding eating meat are frequently ameliorated.”

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“If you eat animal-based sources, these always have all of the essential amino acids, including leucine, which is one of the amino acids that is critical to maximizing muscle protein synthesis,” says Stranberg. “So, if you are eating plant-based protein sources, you need to educate yourself on how to eat complete proteins and obtain the amount of leucine required at each meal to maximize protein synthesis and decrease risk of missing essential amino acids.” Getting complete proteins as a vegan often means combining foods—like rice with beans or hummus with pita.

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Protein deficiencies are rare, but you still should follow the appropriate intake recommendations to build muscle, maintain your energy levels, and feel fully satiated. Fortunately, you have plenty of protein-rich, healthy foods to choose from that will make your body, and your mouth, happy.

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