Venn B J, Green T J
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Eur J Clin Nutr. 2007 Dec;61 Suppl 1:S122-31. doi: 10.1038/sj.ejcn.1602942.
Glycemic index (GI) describes the blood glucose response after consumption of a carbohydrate containing test food relative to a carbohydrate containing reference food, typically glucose or white bread. GI was originally designed for people with diabetes as a guide to food selection, advice being given to select foods with a low GI. The amount of food consumed is a major determinant of postprandial hyperglycemia, and the concept of glycemic load (GL) takes account of the GI of a food and the amount eaten. More recent recommendations regarding the potential of low GI and GL diets to reduce the risk of chronic diseases and to treat conditions other than diabetes, should be interpreted in the light of the individual variation in blood glucose levels and other methodological issues relating to measurement of GI and GL. Several factors explain the large inter- and intra-individual variation in glycemic response to foods. More reliable measurements of GI and GL of individual foods than are currently available can be obtained by studying, under standard conditions, a larger number of subjects than has typically been the case in the past. Meta-analyses suggest that foods with a low GI or GL may confer benefit in terms of glycemic control in diabetes and lipid management. However, low GI and GL foods can be energy dense and contain substantial amounts of sugars or undesirable fats that contribute to a diminished glycemic response. Therefore, functionality in terms of a low glycemic response alone does not necessarily justify a health claim. Most studies, which have demonstrated health benefits of low GI or GL involved naturally occurring and minimally processed carbohydrate containing cereals, vegetables and fruit. These foods have qualities other than their immediate impact on postprandial glycemia as a basis to recommend their consumption. When the GI or GL concepts are used to guide food choice, this should be done in the context of other nutritional indicators and when values have been reliably measured in a large group of individuals.
血糖生成指数（GI）描述了食用含碳水化合物的测试食物后相对于含碳水化合物的参考食物（通常是葡萄糖或白面包）的血糖反应。GI最初是为糖尿病患者设计的，作为食物选择的指南，建议选择低GI的食物。食物摄入量是餐后高血糖的主要决定因素，血糖负荷（GL）的概念考虑了食物的GI和摄入量。关于低GI和GL饮食降低慢性病风险及治疗糖尿病以外病症的最新建议，应根据个体血糖水平的差异以及与GI和GL测量相关的其他方法学问题来解读。有几个因素可以解释个体对食物血糖反应的巨大个体间和个体内差异。通过在标准条件下研究比过去通常情况更多的受试者，可以获得比目前更可靠的个体食物GI和GL测量值。荟萃分析表明，低GI或GL的食物在糖尿病血糖控制和血脂管理方面可能有益。然而，低GI和GL食物可能能量密集，含有大量糖分或不良脂肪，这些都会导致血糖反应减弱。因此，仅就低血糖反应而言的功能性并不一定能证明其具有健康声称。大多数证明低GI或GL有益健康的研究都涉及天然存在且经过最少加工的含碳水化合物的谷物、蔬菜和水果。这些食物除了对餐后血糖有直接影响外，还有其他特性，这也是推荐食用它们的依据。当使用GI或GL概念来指导食物选择时，应该在考虑其他营养指标的背景下进行，并且这些值已经在大量个体中得到可靠测量。
