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Meta-Analysis
. 2020 May 1;11(3):548-558.
doi: 10.1093/advances/nmz106.

Protein Intake Greater than the RDA Differentially Influences Whole-Body Lean Mass Responses to Purposeful Catabolic and Anabolic Stressors: A Systematic Review and Meta-analysis

Joshua L Hudson  1 , Yu Wang  1 , Robert E Bergia Iii  1 , Wayne W Campbell  1
Affiliations
Meta-Analysis

Protein Intake Greater than the RDA Differentially Influences Whole-Body Lean Mass Responses to Purposeful Catabolic and Anabolic Stressors: A Systematic Review and Meta-analysis

Joshua L Hudson et al. Adv Nutr. .

Abstract

Under stressful conditions such as energy restriction (ER) and physical activity, the RDA for protein of 0.8 g · kg-1 · d-1 may no longer be an appropriate recommendation. Under catabolic or anabolic conditions, higher protein intakes are proposed to attenuate the loss or increase the gain of whole-body lean mass, respectively. No known published meta-analysis compares protein intakes greater than the RDA with intakes at the RDA. Therefore, we conducted a systematic review and meta-analysis to assess the effects of protein intakes greater than the RDA, compared with at the RDA, on changes in whole-body lean mass. Three researchers independently screened 1520 articles published through August 2018 using the PubMed, Scopus, CINAHL, and Cochrane databases, with additional articles identified in published systematic review articles. Randomized, controlled, parallel studies ≥6 wk long with apparently healthy adults (≥19 y) were eligible for inclusion. Data from 18 studies resulting in 22 comparisons of lean mass changes were included in the final overall analysis. Among all comparisons, protein intakes greater than the RDA benefitted changes in lean mass relative to consuming the RDA [weighted mean difference (95% CI): 0.32 (0.01, 0.64) kg, n = 22 comparisons]. In the subgroup analyses, protein intakes greater than the RDA attenuated lean mass loss after ER [0.36 (0.06, 0.67) kg, n = 14], increased lean mass after resistance training (RT) [0.77 (0.23, 1.31) kg, n = 3], but did not differentially affect changes in lean mass [0.08 (-0.59, 0.75) kg, n = 7] under nonstressed conditions (no ER + no RT). Protein intakes greater than the RDA beneficially influenced changes in lean mass when adults were purposefully stressed by the catabolic stressor of dietary ER with and without the anabolic stressor of RT. The RDA for protein is adequate to support lean mass in adults during nonstressed states. This review was registered at www.crd.york.ac.uk/prospero as CRD 42018106532.

Keywords: adults; body composition; exercise; fat-free mass; health; weight loss.

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Figures

FIGURE 1
FIGURE 1
Flowchart of the literature search process. RCT, randomized controlled trial.
FIGURE 2
FIGURE 2
The overall and subgroup analyses with ER and with no ER on the effect of consuming greater than the protein RDA compared with the RDA on lean mass changes. *P value for χ2 test for heterogeneity. ER, energy restriction; WMD, weighted mean difference.
FIGURE 3
FIGURE 3
The overall and subgroup analyses with RT and with no RT on the effect of consuming greater than the protein RDA compared with the RDA on lean mass changes. *P value for χ2 test for heterogeneity. RT, resistance training; WMD, weighted mean difference.
FIGURE 4
FIGURE 4
The effect of consuming greater than the protein RDA compared with the RDA with ER + RT and with ER + no RT on lean mass changes. *P value for χ2 test for heterogeneity. ER, energy restriction; RT, resistance training; WMD, weighted mean difference.
FIGURE 5
FIGURE 5
The effect of consuming greater than the protein RDA compared with the RDA in adults without purposeful stressors (with no energy restriction + no resistance training) on lean mass changes. WMD, weighted mean difference. *P value for χ2 test for heterogeneity.
See this image and copyright information in PMC

References

    1. Institute of Medicine. Dietary Reference Intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. Washington (DC): National Academies Press; 2005.
    1. Scrimshaw NS, Schürch B; International Dietary Energy Consultancy Group. Protein-energy interactions: proceedings of an I/D/E/C/G workshop, held in Waterville Valley, NH, USA, October 21 to 25, 1991. Lausanne, Switzerland: Nestlé Foundation; 1992.
    1. Elango R, Ball RO, Pencharz PB. Individual amino acid requirements in humans: an update. Curr Opin Clin Nutr Metab Care. 2008;11(1):34–9. - PubMed
    1. Traylor DA, Gorissen SHM, Phillips SM. Perspective: protein requirements and optimal intakes in aging: are we ready to recommend more than the recommended daily allowance?. Adv Nutr. 2018;9(3):171–82. - PMC - PubMed
    1. Waterlow JC. The mysteries of nitrogen balance. Nutr Res Rev. 1999;12(1):25–54. - PubMed

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