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Cited by 506Muscle metabolism and nutritionNutrition, Health, and Society StudiesNutrition and Health Studies

Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults

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Rand, William M, Pellett, Peter L, Young, Vernon R·2003·The American Journal of Clinical Nutrition
DOI 10.1093/ajcn/77.1.109
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Abstract

Background The most recent international dietary protein recommendations for healthy adults are those developed and proposed by the 1985 FAO/WHO/UNU Joint Expert Consultation. Objective The objective was to analyze available nitrogen balance data to establish new recommendations for the protein required by healthy adults. Design Data were gathered from published nitrogen balance studies that had as their primary objective either the estimation of basal or maintenance requirements or the testing of the adequacy of specific nitrogen intakes in healthy adults. These data were synthesized to characterize the distribution of individual protein requirements; the effects of climate of the study site, adult age, sex, and dietary protein source on individual requirements; and the midpoint of and the variability between the protein requirements of healthy persons. Results Data for 235 individual subjects, each studied at >or= 3 test protein intakes, were gathered from 19 studies. The median estimated average requirement (EAR) of nitrogen from these data was 105 mg N x kg(-1) x d(-1). Individual requirements were found to fit a log-normal distribution. The median EAR was estimated as the median of this distribution, 105 mg N x kg(-1) x d(-1), whereas the 97.5th percentile (the recommended dietary allowance; RDA) was estimated from the distribution of the log of the requirement (after correction of the total observed variability to remove within-individual variability) as 132 mg N x kg(-1) x d(-1). No significant differences between the climate of the study site, adult age class, sex, or source of dietary protein were observed, although there was an indication that women might have a lower requirement than do men. Conclusion This meta-analysis provides new recommendations for dietary reference values, ie, an EAR (median) and RDA (97.5th percentile) for healthy adults of 105 and 132 mg N x kg(-1) x d(-1) (0.65 and 0.83 g good-quality protein x kg(-1) x d(-1)), respectively.

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Research works printed but not linked: 19

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Authors
Rand, W. M., Pellett, P. L., & Young, V. R.
Affiliations
Tufts University (US)
Venue
The American Journal of Clinical Nutrition
Publisher
Elsevier BV
Published
2003-01
Volume
77
Issue
1
Pages
109-127
ISSN
0002-9165 (ISSN-L)
DOI
10.1093/ajcn/77.1.109
OpenAlex
W1839306363
Cited by
506
References
100
Citations by year
2026: 35 · 2025: 26 · 2024: 24 · 2023: 33 · 2022: 23 · 2021: 29 · 2020: 34 · 2019: 23 · 2018: 30 · 2017: 28 · 2016: 23 · 2015: 17 · 2014: 25 · 2013: 24 · 2012: 18
FWCI
0.74
Type
journal article
Language
en
Open access
Licence
Locations
  • American Journal of Clinical Nutrition (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (2r01dk042101-13)
  • National Institute of Diabetes and Digestive and Kidney Diseases (DK 15856, DK 42101)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Nutrition, Health, and Society Studies
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutrition and Health Studies
Keywords
protein requirements, nitrogen balance, healthy adults, estimated average requirement, RDA, dietary reference values, protein sources
MeSH terms
Adolescent, Adult, Aged, Aged, 80 and over, Analysis of Variance, Diet, Dietary Proteins, Female, Humans, Male, Middle Aged, Nitrogen, Nutritional Requirements

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