Rand William M, Pellett Peter L, Young Vernon R
Department of Family Medicine and Community Health, Tufts University Medical School, Boston, MA 02111, USA.
Am J Clin Nutr. 2003 Jan;77(1):109-27. doi: 10.1093/ajcn/77.1.109.
The most recent international dietary protein recommendations for healthy adults are those developed and proposed by the 1985 FAO/WHO/UNU Joint Expert Consultation.
The objective was to analyze available nitrogen balance data to establish new recommendations for the protein required by healthy adults.
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.
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.
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.
最新的针对健康成年人的国际膳食蛋白质建议是由1985年粮农组织/世界卫生组织/联合国大学联合专家磋商会制定并提出的。
目的是分析现有的氮平衡数据，以确立健康成年人所需蛋白质的新建议。
数据收集自已发表的氮平衡研究，这些研究的主要目的要么是估算基础或维持需求量，要么是测试健康成年人特定氮摄入量的充足性。对这些数据进行综合分析，以描述个体蛋白质需求的分布情况；研究地点的气候、成年人年龄、性别和膳食蛋白质来源对个体需求的影响；以及健康人群蛋白质需求的中点值和变异性。
从19项研究中收集了235名个体受试者的数据，每名受试者均在≥3种测试蛋白质摄入量水平下进行了研究。这些数据中氮的估计平均需求量（EAR）中位数为105mg N×kg⁻¹×d⁻¹。发现个体需求符合对数正态分布。中位数EAR被估计为此分布的中位数，即105mg N×kg⁻¹×d⁻¹，而第97.5百分位数（推荐膳食摄入量；RDA）是根据需求对数的分布（在对总观察到的变异性进行校正以消除个体内变异性之后）估计为132mg N×kg⁻¹×d⁻¹。尽管有迹象表明女性的需求量可能低于男性，但未观察到研究地点的气候、成年人年龄组、性别或膳食蛋白质来源之间存在显著差异。
这项荟萃分析提供了膳食参考值的新建议，即健康成年人的EAR（中位数）和RDA（第97.5百分位数）分别为105和132mg N×kg⁻¹×d⁻¹（0.65和0.83g优质蛋白质×kg⁻¹×d⁻¹）。
