Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Eur J Clin Nutr. 2013 May;67(5):522-31. doi: 10.1038/ejcn.2013.27. Epub 2013 Feb 13.
Recent criticisms of the glycaemic index (GI) focus on its validity with assertions that GI methodology is not valid, GI values are inaccurate and imprecise, GI does not predict what foods are healthy and that whole grain and fibre are better markers of carbohydrate quality than GI. None of the critics provide sound reasons for rejecting GI because some of their arguments are based on flagrant errors in understanding and interpretation while others are not supported by current data or are inconsistent with other nutritional recommendations. This paper addresses current criticisms of GI and outlines reasons why GI is valid: (1) GI methodology is accurate and precise enough for practical use; (2) GI is a property of foods; and (3) GI is biologically meaningful and relevant to virtually everyone. Current dietary guidelines recommend increased consumption of whole grains and dietary fibre but do not mention GI. However, this is illogical because the evidence that GI affects health outcomes is at least as good or better than that for whole grains and fibre. GI is a novel concept from a regulatory point of view and a number of problems need to be addressed to successfully translate GI knowledge into practice. The problems are not insurmountable but no progress can be made until bias and misunderstanding about GI can be overcome and there is better agreement about what is the actual state of knowledge on GI so that the real issues can be identified and addressed.
近期对血糖生成指数（GI）的批评主要集中在其有效性上，有人断言 GI 方法无效，GI 值不准确且不精确，GI 不能预测哪些食物健康，全谷物和膳食纤维比 GI 更能反映碳水化合物的质量。批评者都没有提出合理的理由来否定 GI，因为他们的一些观点基于对理解和解释的明显错误，而另一些观点则没有得到现有数据的支持，或者与其他营养建议不一致。本文针对 GI 的当前批评进行了探讨，并概述了 GI 有效的原因：（1）GI 方法在实际应用中足够准确和精确；（2）GI 是食物的特性；（3）GI 在生物学上是有意义的，与几乎所有人都相关。目前的饮食指南建议增加全谷物和膳食纤维的摄入量，但并未提及 GI。然而，这是不合理的，因为 GI 影响健康结果的证据至少与全谷物和膳食纤维一样好或更好。从监管角度来看，GI 是一个新概念，需要解决许多问题才能成功地将 GI 知识转化为实践。这些问题并不是不可克服的，但在克服对 GI 的偏见和误解，并就 GI 的实际知识状况达成更好的共识，从而确定和解决真正的问题之前，不会取得任何进展。
