St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India.
Curr Opin Clin Nutr Metab Care. 2011 Sep;14(5):434-9. doi: 10.1097/MCO.0b013e3283496575.
There are now different stable isotopic methods to measure minimum daily human indispensable amino acid (IAA) requirements. There has been debate on the appropriateness of statistical methods used to define the nature of change in the response.
Current isotopic methods measure daily amino acid oxidation and balance of the IAA under test, or of a selected indicator amino acid, to graded intakes of the test IAA. A key concern is how response curves of oxidation/balance are analyzed to find the inflection point (breakpoint) at which the intake requirement is identified. Evaluating the pattern of the response to identify a breakpoint by a two-phase regression appears best. The indicator amino acid oxidation method has also been shortened and developed into a noninvasive protocol suitable for different populations and age groups.
The indicator amino acid oxidation and balance method might be considered the best approach currently available, but it is challenging. The short-term indicator oxidation method is noninvasive and nondemanding. IAA requirements, based on these methods, have implications for the quality of protein in the dietary intake of populations. Methods that assess the IAA requirements to support optimal body function also need to be developed.
目前有不同的稳定同位素方法来测量人类最低必需氨基酸（IAA）的需求量。对于用于确定响应变化性质的统计方法的适当性存在争议。
目前的同位素方法测量在测试 IAA 的不同摄入量下，氨基酸氧化和 IAA 的平衡，或选定的指示氨基酸的氧化和平衡。一个关键问题是如何分析氧化/平衡响应曲线，以找到确定摄入量需求的拐点（转折点）。通过两相回归评估响应模式以识别转折点似乎是最好的方法。指示氨基酸氧化法也已缩短，并开发为适合不同人群和年龄组的非侵入性方案。
指示氨基酸氧化和平衡法可能被认为是目前可用的最佳方法，但具有挑战性。短期指示氨基酸氧化法是一种非侵入性且要求不高的方法。基于这些方法的必需氨基酸需求量对人群饮食中蛋白质的质量有影响。还需要开发评估支持最佳身体功能的必需氨基酸需求量的方法。
