The Need to Re-evaluate the Adequacy and Application of Protein Requirements

iPB Protein Bite

Protein is a critical macronutrient that supports reproduction, growth, development, health and longevity. Requirement standards for protein have been established by many countries around the world with the intention to set minimal levels of intake to prevent the development of deficiency in most otherwise healthy individuals at different stages of the lifespan. However, it is debated that many of these standards have been set too low, especially for certain populations and that the associated terms and definitions should be reviewed to ensure minimal confusion of their intended application. The iPB supports the need for an up-to-date re-evaluation of protein requirement standards to identify opportunities for improvement, application and globalization of requirement levels.

2018 iPB Consensus Statement on The Need to Re-evaluate the Adequacy and Application of Protein Requirement Standards

Based on the most up-to-date research and understanding of the issue, the International Protein Board presents its 2018 Consensus Statement on the need to re-evaluate protein requirement standards:

" Protein requirement standards should be actively re-evaluated based on the most current information especially for older individuals. In addition, there should be clear communication regarding definition and application of requirement standards to minimize confusion and misinformation. "

iPB Survey 2018

The Need to Re-evaluate the Adequacy and Application of Protein Requirements

iPB Survey question:  Is the current RDA (Recommended Daily Allowance) for protein in the US and Canada (0.8g/kg or 46g Women/56g Men) and other countries is adequate for general population health promotion, and can it be used in diet planning as a daily target protein intake level?

Results: The iPB survey score is 3.75 with answers range from 1 = Strongly Agree to 5 = Strongly Disagree.

iPB Protein Brief

The Need to Re-evaluate the Adequacy and Application of Protein Requirement

Protein is a critical macronutrient that supports reproduction, growth, development, health and longevity. Requirement and/or recommendation standards for protein, in conjunction with other nutrients, have been established by many countries around the world with the intention to set minimal levels of intake to prevent the development of deficiency in most otherwise healthy individuals at different stages of the lifespan. However, experts often proclaim that these standards are set too low especially for certain populations and the terms and definitions should be revisited to ensure the minimize confusion and misinformation as well as proper application.

Protein Requirement Standards Globally

Countries, multi-country unions and organizations around the world have developed requirements for essential nutrients which include protein. For instance, in North America, the United States and Canadian RDA (Recommended Dietary Allowance) for protein is 46 and 54 grams per day for women and men, respectively, or 0.8 grams per kilogram body weight to accommodate variances in body size.1 The RDA represents the estimated average requirement (EAR) plus two standard deviations above to include approximately 98% of the population for different ages, pregnancy and lactation.

Across the Atlantic Ocean, the European Food Safety Authority (EFSA) set the average requirement (AR) for healthy adults to be 0.66 grams of protein per kilogram body weight daily and the PRI (Population Reference Intake) to be 0.83 grams per kilogram body weight.2 EFSA also concluded that at the time of setting these standards there was insufficient data to determine any difference in protein requirement in older adults versus younger counterparts. In addition to EFSA’s standards, countries within the European Union (EU) have developed their own protein requirement standards. For instance, the German Recommended Intakes (RIs) for adults >19 years old are 0.8 grams of protein per kilogram body weight.3 Meanwhile, the French protein requirement for adults <60 years of age matches EFSA’s PRI of 0.83 grams per kilogram body weight, however they increase the requirement to 1 gram per kilogram for older adults.4

The Nordic Nutrition Recommendations (NNR) include Average Requirements (AR) and Recommended Intakes (RI) which align with the EAR and RDAs in concept.5 The NNRs state that the recommended amount of protein ranges from 0.80 to 0.83 g per kilogram of body weight for both men and women with modest levels of physical activity. Recommended amounts for children and pregnant or lactating women are higher, to allow for the deposition of body tissues and the secretion of milk.

On the other side of the world, the Nutrient Reference Values (NRVs) for Australia and New Zealand, which include the EAR and Recommended Dietary Intakes (RDIs) list the RDIs for adult women and men under the age of 70 as 46 and 64 grams daily or 0.75 and 0.84 grams per kilogram body weight. For adult women and men over the age of 70 the RIs increase to 57 and 81 grams daily or 0.94 and 1.07 grams per kilogram body weight.6

The recommendations of the more globally comprehensive World Health Organization (WHO) states that the average requirement (AR) for healthy women and men to be 0.66 grams of protein per kilogram body weight while the SLP (Safe Level of Protein) level of intake was set at 0.83g/Kg per day, expected to meet the protein needs of 97.5% of healthy adult population.7

There are several key points of debate related to existing protein requirements. First, is whether the methodology utilized to establish the initial requirements provided the most accurate and comprehensive (across ages) estimates of protein requirements. Most protein requirements set globally are based on nitrogen balance studies.8 Nitrogen balance assessments is a basic, long-standing method for estimating dietary protein requirements with use as such dating back over a century ago. While certainly useful as a crude assessment tool, many issues have been identified leaving accuracy suspect.8-14 Moreover, re-assessment of nitrogen balance data, as well as newer protein balance methodology such as Indispensable Amino Acid Oxidation (IAAO), suggest that in general base protein requirements are higher, especially for older people.10-14

 

Another key point of debate is whether the intentions of protein requirement standards are misunderstood regarding dietary planning. Requirement standards such as the US RDAs were intended to establish a standard for dietary protein minimums that most people could consume without susceptibility of nutritional inadequacy and the development of signs of protein deficiency. Furthermore, minimum protein requirements are typically only meant to cover age groups as well as pregnancy and lactation. However, within these categories, evidence grows that the current protein requirements around the world might be too low with special considerations for older people and vegetarians, deriving dietary protein from plant and other non-animal sources. On the other hand, base protein requirements typically do not accommodate weight loss, exercise, sport performance, sickness, and disease which in modern times collectively makes up a significant proportion of the population for adults.

 

Protein Requirements vs Recommendations

It is important for professionals as well as general populations to understand that protein requirements are dietary minimums and were not concepted to serve as target for diet planning. Thus, they are dietary requirement or reference intake levels, not necessarily recommendations for food and dietary planning. All too often the scientific councils that set the requirement standard do not continue to set easy to understand recommendations for diet planning. On the other hand, intake ranges based on percentage of energy might be provided with the lower end of the range approximating protein requirements. For instance, the AMDR (Acceptable Macronutrient Distribution Range) in the US and Canada provide a range of protein as 10-35% of energy intake. However, this broad range is not well understood and successfully translated to individual diet planning for various reasons. For instance, while the low end of the range approximates the RDA is not a true protein recommendation level for general health and wellness.  Furthermore, if 10% of energy was indeed the target for dietary planning, this in turn would leave 90% of the energy to be split between carbohydrate and fat, which might not be aligned with optimal health.

One example of the combination of requirements combined with recommendations involving percentage ranges and a target was presented in the NNRs. These standards go beyond base protein requirements to state that for food planning purposes, a suitable target for protein intake for healthy, active adults should be 15% of energy corresponding to about 1.1 grams of protein per kilogram body weight daily. This recommendation is advanced to 18% of energy and 1.2 grams of protein per kilogram body weight for elderly. In addition, the daily protein range is 10-20% and 15-20% of energy for people 2 to 65 and >65 years of age.  

One reason for confusion when it comes to making recommendations for protein intake more supportive of health and wellbeing is that Upper Limits (ULs) are not commonly stated for protein. This can leave opportunity for speculation as to safety at levels above minimum requirements and even at the upper end of ranges such as 20% and 35% of energy. However, by and large evidence for concern of protein intakes doubling requirement standards and even higher are not plentiful. For instance, the NRVs for Australia and New Zealand state that no UL was set as there is insufficient data.6 However, they do state that a UL of 25% protein as energy is recommended for which the rationale is applied to a specific chronic disease. Elsewhere the WHO states that no safe upper limit has been identified, and it is unlikely that intakes of twice the safe level are associated with any risk. Meanwhile, they do recommend caution for intakes of three to four times the safe intake cannot be assumed to be risk-free.7 Hopefully the recognition that that a lack of clear evidence that higher intake levels, such as double minimum requirements, do not pose a health risk will allow for more recommendations to be made and in turn make it easier for people to understand and apply.

 

At this time the iPB recommends the re-evaluation of minimum protein requirement standards based on the latest understanding of minimum protein requirements for general health and wellness across age groups, especially older people, and based on more modern techniques of minimum requirement assessment. Furthermore, it is important to evaluate the understanding of the requirement standards and how they are utilized by professionals and applied by the general population. In addition to requirements, which set minimum threshold for most people, more emphasis should be place on recommendations as well as education regarding flexibility and personalization in protein planning in the diet.

Citations

  1. Institute of Medicine. 2005. Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Protein and Amino Acids (Macronutrients). The National Academies Press, Washington, DC, USA.
  2. EFSA (2012) European Food Safety Authority, Scientific Opinion on Dietary Reference Values for protein. EFSA Journal 2012; 10(2):2557
  3. EsKiMo (2007), Ernährungsstudie als KiGGS-Modul, Nutrition module in the German Health Interview and Examination Survey for Children and Adolescents
  4. AFSSA (Agence Française de Sécurité Sanitaire des Aliments), 2007. Apport en protéines: consommation, qualité, besoins et recommandations.
  5. New Nordic Nutrition Recommendations are here. Food & Nutrition Research 2013. 57 : 22903
  6. Nutrient Reference Values for Australia and New Zealand. Including Recommended Dietary Intakes https://www.nrv.gov.au/nutrients/protein
  7. WHO/ FAO/ UNU (2007) World Health Organization/ Food and Agriculture Organization/ United Nations University, Protein and amino acid requirements in human nutrition; Report of a joint FAO/WHO/UNU Expert Consultation Technical Report Series No 935. WHO, Geneva (2007)
  8. Medeiros DM & Wildman REC. Protein & Amino Acids, In: Advanced Human Nutrition. Jones & Bartlett 2018.
  9. Pencharz PB, Elango R, Wolfe RR. Recent developments in understanding protein needs – How much and what kind should we eat? Applied Physiol Nutr Metabol. 41:577-580. March 2016.
  10. Paddon-Jones D, Campbell WW, Jacques PF, Kritchevsky SB, Moore LL, Rodriguez NR, van Loon LJ. Protein and healthy aging. Am J Clin Nutr. 2015 (101) (suppl):1339S-45S. (Open Access)
  11. Phillips SM, Chevalier S, Leidy HJ. Protein “requirements” beyond the RDA: implications for optimizing health. Appl. Physiol. Nutr. Metab. 41: 565–572 (2016). (Open Access Article)
  12. Courtney-Martin G, Ball RO, Pencharz PB, Elango R. Protein Requirements during Aging. Nutrients. 2016 Aug 11;8(8). (Open Access Free Article)
  13. Baum JI, Kim IY, Wolfe RR. Protein Consumption and the Elderly: What Is the Optimal Level of Intake? Nutrients. 2016 Jun 8;8(6).
  14. Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, Phillips SM, Sieber C, Stehle P, Teta D, Visvanathan R, Volpi E, Boirie Y. Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: A Position Paper From the PROT-AGE Study Group. JAMDA 14 (2013) 542e559. (Open Access)

iPB Approved Resources

PodCasts

Coming Soon

Internet-Based Resources

The European Commission overviews information and matters related to protein requirement. European Commission’s Science and Knowledge Service: Dietary Protein.

Videos

Dr Stu Phillips is interviewed on How Much Protein Do We Need.  Q/A includes discussion of protein needs during aging, exercise and general intake.

Dr Rob Wildman discusses the need for harmonised protein recommendations worldwide