Livesey Geoffrey
Independent Nutrition Logic Ltd, Wymondham, Norfolk, UK.
Proc Nutr Soc. 2005 Feb;64(1):105-13. doi: 10.1079/pns2004400.
The present review considers the background to terminology that relates foods, glycaemia and health, including 'available carbohydrate', 'glycaemic index' (GI), 'glycaemic glucose equivalent', 'glycaemic response index' and 'net carbohydrate', and concludes that central to each of these terms is 'glycaemic load' (GL). GL represents the acute increase in exposure of tissue to glucose determined by foods; it is expressed in ingested glucose equivalents (per 100 g fresh weight or per serving), and is regarded as independent of the state of glucose metabolism from normal to type 2 diabetes mellitus (T2DM). Ad libitum studies in overweight or obese adults and children show that low-GL diets are associated with marked weight benefits, loss of adiposity and reduced food intake. Weight benefits appear on low-glycaemic v. high-glycaemic available carbohydrates, unavailable v. available carbohydrates and protein v. available carbohydrate. Energy intake immediately after lowering of meal GL via carbohydrate exchanges is apparent only after a threshold cumulative intake of >2000 MJ. Various epidemiological and interventional studies are discussed. A relationship between GL and the development of T2DM and CHD is evident. Studies that at first seem conflicting are actually consistent when data are overlaid, such that diets with a GL of >120 glucose equivalents/d would appear to be inadvisable. Whereas certain studies might place GI as being slightly stronger than GL in relation to T2DM risk, this situation appears to be associated with observations in a lower range of GL or when the range of GI is too narrow for accuracy; nevertheless, authors emphasise the importance of GL. Among the studies reviewed, GL offers a better or stronger explanation than GI in various observations including body weight, T2DM in nurses, CHD, plasma triacylglycerols, HDL-cholesterol, high-sensitivity C-reactive protein and protein glycation. Where information is available, the associations between risk factors and GL are either similar or stronger in the overweight or obese, as judged by BMI, and apply to both body weight and blood risk factors. The implications tend to favour a long-term benefit of reducing GL, for which further study is necessary to eliminate any possibility of publication bias and to establish results in clinical trials with overweight and obese patients.
本综述探讨了与食物、血糖和健康相关术语的背景，包括“可利用碳水化合物”、“血糖生成指数”（GI）、“血糖葡萄糖当量”、“血糖反应指数”和“净碳水化合物”，并得出结论，这些术语的核心都是“血糖负荷”（GL）。GL表示食物所决定的组织对葡萄糖暴露的急性增加；它以摄入的葡萄糖当量表示（每100克新鲜重量或每份），并且被认为与从正常到2型糖尿病（T2DM）的葡萄糖代谢状态无关。对超重或肥胖成年人及儿童的随意饮食研究表明，低GL饮食与显著的体重益处、脂肪减少和食物摄入量降低有关。在低升糖指数与高升糖指数的可利用碳水化合物、不可利用碳水化合物与可利用碳水化合物以及蛋白质与可利用碳水化合物之间，均出现了体重益处。通过碳水化合物交换降低餐食GL后，能量摄入仅在累积摄入量超过2000兆焦耳的阈值后才明显。文中讨论了各种流行病学和干预性研究。GL与T2DM和冠心病发展之间的关系是明显的。起初看似相互矛盾的研究，当数据叠加时实际上是一致的，因此GL大于120葡萄糖当量/天的饮食似乎不可取。虽然某些研究可能认为在T2DM风险方面GI比GL略强，但这种情况似乎与GL较低范围内的观察结果有关，或者当GI范围过窄而不准确时；尽管如此，作者强调了GL的重要性。在所审查的研究中，在包括体重、护士中的T2DM、冠心病、血浆甘油三酯、高密度脂蛋白胆固醇、高敏C反应蛋白和蛋白质糖基化等各种观察中，GL比GI提供了更好或更强的解释。在有信息可查的情况下，根据BMI判断，超重或肥胖人群中风险因素与GL之间的关联要么相似，要么更强，并且适用于体重和血液风险因素。其影响倾向于支持降低GL的长期益处，为此需要进一步研究以消除发表偏倚的任何可能性，并在超重和肥胖患者的临床试验中确定结果。
