What's the ideal protein dose?

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Just when you thought the topic of protein had been sliced, diced, and hydrolyzed to a fare-thee-well, along comes another angle to contemplate: How much is enough? Or, perhaps more pointedly, how much is enough to optimize protein’s benefits-for muscle building, weight management, healthy aging, or any of the other facets of wellness it’s known to improve?

Of course, the question of protein “dosing” is nothing new, either for consumers or the product developers who court them. But by focusing on how much protein they pack into their formulations, product developers not only have a chance to help their audience meet their protein goals; they might also give their protein applications an edge in a crowded marketplace.

What’s in a Name?

It’s not hard to understand why consumers are clamoring for more protein. As Matthew Pikosky, PhD, RD, vice president, nutrition research, Dairy Management Inc. (DMI; Rosemont, IL), says, “Protein is an essential component of everyone’s diet. While typically associated with muscle health, it also supports bones, ligaments, and tendons; moves oxygen to muscles; helps us metabolize other nutrients; and takes part in keeping the immune system healthy.”

But where the equation starts getting tricky is in figuring out the protein “dose” to add to a particular product aimed at a particular consumer or purpose. And even here, notes Ermel Manuel, sports nutrition applications technical sales manager, FrieslandCampina Ingredients North America Inc. (Paramus, NJ), dose might not be the right word to have in mind.

“Dose is a term normally used in medicine and so doesn’t really fit with protein fortification,” he says. Neither does level, he believes, as he thinks it could be confused with the “levels” of protein structure that you may (or may not) remember learning about in college molecular biology class.

In any case, the bottom line for Manuel, at least, is that the amount of protein in a product-or an individual’s diet-should take its cues from the Dietary Reference Intakes (DRIs) and Recommended Daily Allowances (RDAs) that the Institute of Medicine, through its Food and Nutrition Board, sets for key nutrients-protein included. “So as long as you’re talking about the DRI or RDA,” he says, “it doesn’t matter whether you call it a ‘dose’ or ‘level.’”

Setting a Floor

DMI’s Pikosky also sees value in leaning on those guidelines. “When discussing protein, it’s best to start with a grounding in current protein recommendations established by the Food and Nutrition Board of the Institute of Medicine,” he agrees. And as it stands, the RDA for protein for adults aged 18 and above is 0.8 g per kg body weight per day, which works out to 0.36 g of protein per lb, or 56 g per day for a 154-lb person.

Another way of specifying recommended protein intake is with the acceptable macronutrient distribution range (AMDR), which, as Pikosky explains, gives “a range of intake for a particular energy source that’s associated with reduced risk of chronic diseases while providing adequate intakes of essential nutrients.” Expressed as a percentage of total calories consumed, the AMDR for protein is 10%-35%, or 50 to 175 g of protein within a 2,000-calorie daily diet.

But while both the AMDR and the RDA set minimum protein consumption levels designed to avoid deficiency-and the consequences of it, including compromised growth in children, loss of muscle mass in adults, and frailty in seniors-neither lays out a plan for protein optimization.

Indeed, the goal of the AMDR is reduced risk of chronic disease; and as it’s defined, the RDA merely estimates the minimum daily average dietary intake to meet the protein requirements of 97%-98% of healthy individuals. In other words, says Pikosky, these guidelines “can be used to set the floor, so to speak, that people should be aiming for.” But they won’t help consumers maximize their protein potential, or reach more ambitious wellness goals.

Beyond Basic

That’s where consuming more protein than in baseline recommendations can bring an advantage. As Kara McDonald, vice president, global marketing communications, U.S. Dairy Export Council (USDEC; Arlington, VA), says, “The evidence continues to build on the benefits of higher-protein diets-curbing hunger, maintaining a healthy weight, enhancing exercise recovery, getting lean, and maintaining muscle as we age.”

Pikosky agrees. “As research evolves,” he says, “health and wellness professionals are looking beyond minimum requirements to explore optimal protein levels that can provide benefits. A growing body of research supports the benefits of higher-protein diets-within the AMDR-for athletes and highly active adults, for weight management and to foster healthy aging.”

He believes the sports and exercise spaces have matured most in recognizing the importance of optimal protein intake, noting the “large body of science” underlying the benefits of whey protein and dairy foods in particular in promoting muscle recovery following exercise.

A 2016 joint position stand on nutrition and athletic performance from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians of Canada noted that dairy proteins appear superior to other proteins tested thanks to their content of the branched-chain amino acid leucine, as well as “the digestion and absorptive kinetics of branched-chain amino acids in fluid-based dairy foods,” Pikosky says. The position recommended 1.2 to 2.0 g of protein per kg body weight per day for adults to support muscle recovery from routine, vigorous exercise.

Similarly, the International Society of Sports Nutrition states in its 2017 position stand on protein and exercise, “Overall, research has shown that products containing animal and dairy-based proteins contain the highest percentage of EAAs”-essential amino acids-“and result in greater hypertrophy and protein synthesis following resistance training when compared to a vegetarian protein-matched control, which typically lacks one or more EAAs.”

As for weight management, research shows that of all the macronutrients, protein-and higher-protein diets especially-produces the sense of satiety that can help reduce energy intake and, thereby, support weight management, Pikosky says.

“Additionally, one of the primary goals of anyone on a weight-loss plan is to preferentially lose body fat while preserving muscle mass, as muscle is important to supporting activities of daily living as well as contributing to resting energy expenditure,” Pikosky adds. To this end, higher protein intakes within the context of broader calorie reduction support muscle maintenance better than lower- or adequate-protein diets.

And in terms of healthy aging, “Eating sufficient amounts of high-quality protein, along with routine exercise, is essential to helping ensure you can age healthfully,” says Pikosky. Why? “The quantity and quality of one’s muscle tissue directly impacts one’s ability to perform general activities-think carrying groceries from the car up a flight of stairs, doing basic yardwork, playing with kids or grandkids.”

To maintain this muscle mass and function, the PROT-AGE Study Group1¹ convened by the European Union Geriatric Medicine Society, in cooperation with other scientific organizations, recommends that older people consume more protein than their younger counterparts: 1.0 to 1.2 g per kg body weight per day. For those with a specific acute or chronic disease, recommended levels rise to 1.2 to 1.5 g per kg body weight daily, and for those with severe illness, injury, or marked malnutrition, 2.0 g per kg body weight per day should fill the bill.

Go for the Goal

So are these the “optimum” protein intakes we’re looking for? It depends.

According to Jose Antonio, PhD, CEO and co-founder of the International Society of Sports Nutrition, associate professor of exercise and sport science at the Nova Southeastern University College of Health Care Sciences, and editor-in-chief of the Journal of the International Society of Sports Nutrition (Fort Lauderdale, FL), “The primary issue with protein dosing is the goal of the individual: Are they an endurance athlete? Strength-power athlete? Or are they just a recreational exerciser?” (He might as easily ask if they exercise at all.)

“In the end, there’s no ‘optimal’ dose,” Antonio concludes, “only a range that’ll serve the needs of the individual, depending on their goals.”

Quality Time

Pikosky agrees. “Ultimately, protein intake recommendations need to be personalized to a variety of factors: age, weight, activity level, health goals, etc.,” he says. “They also need to be considered within the broader context of an individual’s overall dietary needs.”

And they need to account for protein quality, which he says “is an important consideration that shouldn’t be overlooked when thinking about optimizing protein intake.”

As hinted at earlier, a protein’s quality reflects its amino acid composition-ideally supplying the full array of EAAs that the human body can’t produce on its own and in amounts sufficient to meet the body’s needs-as well as its digestibility and the amino acids’ bioavailability once digested and absorbed.

And it matters for protein intake optimization, Pikosky says, because “to obtain a similar amount of biologically available essential amino acids from a lower-quality protein would require that one consume more of the food or protein source.” From a practical standpoint, he says, “it makes sense to try to deliver those essential amino acids efficiently via foods that provide a highly concentrated, highly digestible, and biologically available source of them.”

Pikosky reiterates that the whey and casein proteins in dairy are among the highest-quality proteins available, with a protein digestibility corrected amino acid score (PDCAAS) of 1 and among the highest gram-for-gram concentrations of EAAs, including the branched-chain amino acid (BCAA) leucine. BCAAs are “primary drivers of muscle protein synthesis, ultimately leading to the building and maintenance of muscle,” Pikosky says.

By contrast, plant proteins tend to have lower quality scores because their amino acid complements lack certain EAAs, supply them in the wrong proportions, or are simply less digestible or bioavailable.

“Protein recommendations are now starting to incorporate considerations for protein quality,” Pikosky notes, with the aforementioned 2016 joint position stand on nutrition and athletic performance advising athletes and vigorously active adults to get 20 to 30 g of high-quality protein, providing about 10 g of EAAs, after workouts and at main meals. “Additionally,” he says, “the PROT-AGE Study Group recommends 25 to 30 g of protein and 2.5 to 2.8 g of leucine per meal. This is another example of how it’s not solely about trying to achieve a total protein target, but a targeted amount of essential amino acids and leucine to optimize the muscle protein synthesis response.”

It’s About Time

“In addition to total protein intake and the type, or quality, of protein consumed,” Pikosky continues, “protein timing, or the distribution of how one consumes that protein over the course of the day, is the last piece of the protein intake puzzle.”

Data from the CDC’s National Health and Nutrition Examination Surveys (NHANES) show that Americans typically “backload” their protein consumption, “eating small amounts at breakfast, moderate amounts at lunch, and large amounts at dinner,” Pikosky says. “Some experts have hypothesized that this isn’t the most effective way to distribute protein intake, as our ability to use protein and amino acids to stimulate protein synthesis appears to have a threshold-a point of diminishing returns where additional protein beyond that threshold will not result in further increased protein synthesis.”

Current research puts that threshold at about 20 g of high-quality protein, with 10 g of essential amino acids, for adults, and 30 g of high-quality protein, with about 15 g of essential amino acids, for older adults. “Eating moderate amounts of high-quality protein at each main meal to maximize muscle protein synthesis throughout the day can serve as a practical strategy to support muscle health,” Pikosky says.

It’s even more important for athletes hoping to build muscle beyond the level of basic strength and health. “It’s been proven that having protein in your system pre- and post-workout is important with muscle building,” says FrieslandCampina’s Manuel. “Our bodies go through a cycle of muscle protein breakdown and synthesis, and when we don’t have enough protein in our systems, then the breakdown becomes more significant than the synthesis. What we want to avoid is not having enough protein to continue synthesis.”

That’s one reason Manuel suggests athletes consume casein in the evening, as its longer digestion horizon “helps continue the cycle over the extended time when you’re not taking in protein,” he explains.

By contrast, for athletes hoping to drive quick-digesting protein into hungry muscles right after exertion, Aaron Fanning, science manager, nutrition, NZMP, the global ingredients brand of dairy cooperative Fonterra (Auckland, New Zealand), recommends his company’s SureProtein Fast MPC brand of milk protein concentrate. Its quickly digested proteins supply more amino acids to muscles within the first two hours of consumption than do standard milk proteins, he says, “challenging conventional thinking on how fast proteins can deliver nutrition to the body.”

On the Shelf

As for how much of these, or any other, proteins should be formulated into a product serving, brands have some tough decisions to make.

One guide for deciding is to look at products already on shelves, where protein levels “vary vastly and cater to consumer needs,” Manuel says, and can range from as low as 2 to 3 g of protein per bar to fully 50 g per beverage. As always, he says, “This really depends on what consumer you want to cater to and what their needs are.”

It also depends on how much protein a formulation can sustain without taking a hit to its sensory profile. “Producing products with a high level of protein is challenging in terms of maintaining good taste and texture,” Fanning says. “To move into the higher doses that consumers are becoming accustomed to-up to 20 g and above-requires use of specialized ingredients that allow fortification without compromise.”

Years of protein R&D have given the industry an impressive catalogue of protein ingredients that do just that, including NZMP’s branded SureProtein WPC 550, a concentrated, shelf-stable whey protein that allows formulations to palatably deliver a protein dose of up to 14% “to help build, repair, and maintain muscle,” Fanning says.

As for the search for that optimum protein dose, Manuel believes that the best advice for any formulator is “to truly understand your target consumer and formulate to their needs.” Those needs will determine protein levels, recommended timing and preferred source-even product platform. “After all, they’re the ones who are going to use the product.”

References

1. Bauer J et al. “Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group.” Journal of the American Medical Directors Association, vol. 14, no. 8 (August 2013): 542-559

CORRECTION: This article was corrected on 12/13/2018, 11 AM PST.

Nutritional Outlook misquoted Matthew Pikosky, PhD, RD, vice president, nutrition research, Dairy Management Inc. (DMI; Rosemont, IL), as saying the AMDR for protein is 10%-15%, or 50 to 175 g of protein within a 2,000-calorie daily diet. The correct range should be 10%-35% g of protein within a 2,000-calorie daily diet. Nutritional Outlook apologizes for the error.

Sidebar 1:

The Kids Are All Right?

Adequate protein consumption is just as important to our little ones as it is to adults. So what does an appropriate dose for kids look like? Also, are children currently getting the amount of protein that they should, and what happens if they don’t?

Jeffrey Bernstein, food scientist at protein powder company Instapro (Burlington, NJ), a sister company to protein supplier AMCO Proteins, says data show that there are some groups in which intake is markedly low. “According to the National Health and Nutrition Examination Survey (NHANES), absolute protein intake is lowest in children ages one to three, regardless of socioeconomic status. These developmental years are instrumental, and ensuring that children receive good-quality protein is paramount to their long-term health.”¹

School-aged children in the one- to seven-year-old age group also do not get enough daily protein, according to NHANES, he says. “The myriad effects associated with poor protein intake are poor concentration in school, decreased immunity, delayed growth, poor bone and joint development, chronic hunger, and more.”

What should children be consuming? Bernstein says the current dietary reference intake (DRI) for protein for children is 0.87 g per kg body weight and 0.76 g per kg body weight for children ages 1 to 3 and 4 to 8, respectively. These DRIs reflect the “minimum amount of dietary protein required to prevent a negative nitrogen balance, an indicator of protein deficiency.”

And, Bernstein says, the current protein DRI for children was shown in a 2011 study² to “severely underestimate protein needs as determined by the amino acid oxidation method.” This is when supplementation can help. For instance, Bernstein says, adding one or two packets daily of his company’s protein powder delivers approximately 50% of the current recommended daily allowance (RDA) of protein for a child weighing 40 lb and in doing so “will help bring children’s net protein intake above current average levels” and will “help parents fortify their children’s foods with additional protein.”

By Jennifer Grebow, Editor-in-Chief

References

1. Berryman C et al. “Protein intake trends and conformity with the Dietary Reference Intakes in the United States: Analysis of the National Health and Nutrition Examination Survey, 2001-2014.” American Journal of Clinical Nutrition, vol. 108, no. 2 (August 1, 2018): 405-413

1. Elango R et al. “Protein requirement of healthy school-age children determined by the indicator amino acid oxidation method.” American Journal of Clinical Nutrition, vol. 94, no. 6 (December 2011): 1545-1552

Sidebar 2:

Getting the Most from Protein

If you’re going to buy a protein product, chances are you’d like to make sure that you’re getting the most from that product. There are several ingredients on the market today that can be formulated concurrently with protein specifically to help improve the body’s absorption of amino acids from the supplemental protein.

Nutrition 21’s (Purchase, NY) Velositol ingredient is a patented amylopectin chromium dietary complex that, when added to protein, helps increase the body’s uptake of amino acids-in effect, “doubling the power of protein,” the company says. As Mallory Junggren, senior director of marketing, explains, Velositol stimulates insulin release and allows the body to safely increase insulin levels, which in turn triggers the body to enhance its amino acid uptake and thereby stimulate muscle protein synthesis. This mechanism was borne out most recently in a 2017 study published in the Journal of the International Society of Sports Nutrition¹.

At this year’s International Society of Sports Nutrition conference in Florida, Nutrition 21 presented new preclinical trial results further indicating how Velositol works to enhance muscle protein synthesis. The study, which examined Velositol’s effects when added to branched-chain amino acids (BCAA), pea protein, and increasing doses of whey protein, found that Velositol helped significantly increase the activity of the signaling proteins involved in the mTOR pathway-the primary pathway that regulates muscle protein synthesis and muscle hypertropy (growth of muscle cells). “These results suggest that Velositol initiates and enhances muscle protein synthesis through activation of key downstream signaling factors in the mTOR pathway that are known to be involved in muscle growth and function. These new findings give insight into the mechanism by which Velositol enhances muscle protein synthesis,” Junggren says.

Protein-product marketers are taking advantage of Velositol’s ability to boost protein efficacy to set their products apart in the market. Companies like nutraceutical brand Medical Research Institute (MRI; Fairfield, OH) are not only adding Velositol to their protein products but calling out the benefits of Velositol right on the product label for the consumer to see. For instance, MRI’s Hydrolyzed Whey Protein Isolate product, launched last year, boasts “Double the Power of Whey Protein” right on the label. At least 20 products on the market now feature Velositol, including post-workout protein powders, ready-to-drink post-workout beverages, and BCAA post-workout muscle-building powders, says Junggren. And the ingredient is not limited to sports nutrition products, either.

Velositol’s protein-boosting got us wondering: 1) is there ever danger that consumers will, as a result, get too high of a protein dose, and 2) if a company includes Velositol in its formulation, can it cut down on the amount of protein in the product and still get the same desired effect? We asked Nutrition 21’s senior manager, scientific affairs, Sara Perez-Ojalvo.

First, she says, while long-term protein intake above the recommended dietary allowance for adults is not advised and can lead to disorders in liver and kidney function, studies on Velositol have shown no adverse effects compared to placebo. Furthermore, she says, in a preclinical study looking at the effect of Velositol on liver and kidney function, researchers not only did not find any adverse effects on liver and kidney function but in fact saw a greater increase in levels of the enzyme aspartate aminotransaminase (AST) in Velositol subjects, suggesting that Velositol may actually promote healthy liver function. She says this study will be published soon.

The company says Velositol is Generally Recognized as Safe at 2 g. The flavorless powder can be used in protein drinks and a variety of meal-replacement, energy, and protein bars. Perez-Ojalvo says the chromium picolinate fraction of the ingredient has also been shown to be safe at “extremely high doses.”

Velositol can even help products with low protein doses better their effects on muscle protein synthesis-which ultimately expands its uses to a broad range of consumers.

Perez-Ojalvo explains, “There are many cases where products have lower doses of protein, including some protein bars or breakfast/meal-replacement bars, products marketed towards women who want lower-calorie products, and products marketed to the aging population where it can be difficult for them to ingest high doses of protein. Velositol is a great addition to these products because at just 2 g, it does not add a lot of bulk or calories, but it boosts the effect of protein on muscle protein synthesis and in a clinical study was shown to double the effect of 6 g of protein on muscle protein synthesis (MPS).¹”

Nutrition 21 also has preclinical animal data, presented at the International Society of Sports Nutrition conference, to show that Velositol increases muscle protein synthesis when used with both low- and high-dose protein products. “In a preclinical study, 6 g of whey protein with Velositol led to the same amount of MPS as 20 g of whey protein alone, and 20 g of whey protein with Velositol led to more MPS than 30 g or 40 g of whey protein alone, showing that Velositol can make your protein work harder for you at both low and high doses of protein,” Perez-Ojalvo says. “This means that it is a good idea to add Velositol to products with less protein like bars or those targeted to populations that want low-calorie protein products, because it makes low doses of protein more effective.”

“But no matter the amount of protein you take, Velositol is a smart addition as it boosts the effect of protein on MPS so you get greater benefits,” she concludes.

Another company, Kerry (Beloit, WA), offers a probiotic ingredient, Ganeden BC30 (Bacillus coagulans GBI-30, 6086), which, when paired with protein, was shown to help that protein more significantly increase recovery, reduce muscle damage, and help promote physical performance post-exercise. In a 2016 athlete study², researchers found Ganeden BC30 added to 20 g of protein-in this case, casein-was able to enhance levels of protection against muscle damage compared to casein alone.

By Jennifer Grebow, Editor-in-Chief

References

1. Ziegenfuss TN et al. “Effects of an amylopectin and chromium complex on the anabolic response to a suboptimal dose of whey protein.” Journal of the International Society of Sports Nutrition. Published online February 8, 2017.
2. Jäger R et al. “Probiotic Bacillus coagulans GBI-30, 6086 reduces exercise-induced muscle damage and increases recovery.” PeerJ. Published online July 21, 2016.

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