Faculty of Biomedical and Life Sciences, University of Glasgow, Thomson Building, Glasgow G12 8QQ, UK.
Med Hypotheses. 2010 Jul;75(1):115-9. doi: 10.1016/j.mehy.2010.02.003. Epub 2010 Feb 21.
Waist circumference (WC) is an obvious indicator of adiposity, but there is a confusing diversity of approaches to its quantitative use. Because taller people of any given relative fat content tend to have bigger WCs, indices of adiposity commonly take the form WC/height(q), where q is 1 or less. Sometimes the influence of height is regarded as insignificant, so that q is taken as zero. More attention has been given to such indices than to establishing how to use them for predicting adiposity. The usual approach has been empirical and statistical, but many published findings can be integrated using a more analytical approach. This leads to several hypotheses that are supported by published evidence, but which remain to be fully tested. Testing mainly requires data sets of the kind that have already been used for related purposes. The main hypotheses are as follow. For adults, the preferred index is WC/height(0.5), while for adolescents and children it is WC/height. However, to obtain equations for the prediction of percentage body fat, the latter should be regressed on the reciprocals of the squares of these indices, namely 1/(WC(2)/height) and 1/(WC/height)(2) respectively. These expressions decrease with increasing percentage body fat, but should do so in a linear manner. Two other hypotheses are that the non-fat content of the abdomen tends to increase with percentage body fat and that the ratio WC(2)/height is approximately proportional to the body mass index. The analysis is based mainly on the following ideas: firstly, that the area of fat or adipose tissue in a transverse computed tomogram of the abdomen equals the total area less the fat-free area, the former being the main determinant of WC and the latter being partly determined by fat-free body size as represented by height; secondly, that guidance can be usefully be sought in simple, dimensionally-correct models of body form, but that parameters in the resulting equations may become attenuated by the necessary use of regression analysis or the maximizing of correlations. There may be a better measure of fat-free body size with which to replace height in these indices, but the waist-to-hip ratio is unhelpful. It is hoped that this analysis can be usefully extended to the problem of estimating intra-abdominal (visceral) fat from waist circumference.
腰围（WC）是肥胖的明显指标，但在定量使用腰围方面存在着令人困惑的多样性。由于任何给定的相对脂肪含量较高的人往往腰围较大，因此肥胖指数通常采用 WC/身高（q）的形式，其中 q 为 1 或更小。有时，身高的影响被认为是微不足道的，因此 q 被视为零。人们对这些指数的关注比对如何使用它们来预测肥胖的关注更多。通常的方法是经验和统计，但使用更具分析性的方法可以整合许多已发表的发现。这导致了几个假设，这些假设得到了已发表证据的支持，但仍有待充分验证。测试主要需要已经用于相关目的的数据。主要假设如下。对于成年人，首选指数是 WC/身高（0.5），而对于青少年和儿童，首选指数是 WC/身高。然而，为了获得预测体脂百分比的方程，后者应回归到这些指数的平方的倒数上，即分别为 1/(WC(2)/height) 和 1/(WC/height)(2)。这些表达式随着体脂百分比的增加而减小，但应该以线性方式减小。另外两个假设是腹部非脂肪含量随体脂百分比增加而增加，以及 WC(2)/height 的比值与体重指数大致成比例。该分析主要基于以下想法：首先，腹部横向计算机断层扫描的脂肪或脂肪组织面积等于总面积减去无脂肪面积，前者是 WC 的主要决定因素，后者部分由代表身高的无脂肪身体大小决定；其次，可以从简单的、尺寸正确的体型模型中寻求有用的指导，但回归分析或最大相关的必要性会使结果方程中的参数减弱。这些指数中可能有更好的无脂肪身体大小的衡量标准来替代身高，但腰臀比没有帮助。希望这种分析能够有用地扩展到从腰围估计腹部（内脏）脂肪的问题。
