Department of Nutrition Science, Purdue University, West Lafayette, IN, USA.
Adv Nutr. 2020 May 1;11(3):548-558. doi: 10.1093/advances/nmz106.
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.
在应激条件下，如能量限制（ER）和身体活动，推荐的 0.8g·kg-1·d-1 蛋白质 RDA 可能不再适用。在分解代谢或合成代谢条件下，建议摄入更高的蛋白质来分别减轻全身瘦体重的损失或增加全身瘦体重的获得。没有已知的已发表的荟萃分析比较大于 RDA 的蛋白质摄入量与 RDA 摄入量。因此，我们进行了一项系统评价和荟萃分析，以评估大于 RDA 的蛋白质摄入量与 RDA 相比对全身瘦体重变化的影响。三位研究人员使用 PubMed、Scopus、CINAHL 和 Cochrane 数据库独立筛选了 2018 年 8 月之前发表的 1520 篇文章，并在已发表的系统评价文章中发现了额外的文章。随机、对照、平行研究，持续时间至少 6 周，纳入健康成年人（≥19 岁）。最终总体分析包括 18 项研究，涉及 22 项瘦体重变化的比较。在所有比较中，与摄入 RDA 相比，大于 RDA 的蛋白质摄入量有利于瘦体重的变化[加权平均差异（95%CI）：0.32（0.01，0.64）kg，n=22 项比较]。在亚组分析中，ER 后，大于 RDA 的蛋白质摄入量减轻了瘦体重的损失[0.36（0.06，0.67）kg，n=14]，阻力训练（RT）后增加了瘦体重[0.77（0.23，1.31）kg，n=3]，但在非应激条件下（无 ER+无 RT）对瘦体重的变化没有差异影响[0.08（-0.59，0.75）kg，n=7]。当成年人受到饮食 ER 的分解代谢应激和/或 RT 的合成代谢应激的有意压力时，大于 RDA 的蛋白质摄入量对瘦体重的变化有有益的影响。RDA 蛋白质足以在非应激状态下支持成年人的瘦体重。本综述在 www.crd.york.ac.uk/prospero 上注册为 CRD 42018106532。
