Keim N L, Mayclin P L, Taylor S J, Brown D L
US Department of Agriculture, Western Human Nutrition Research Center, Presidio of San Francisco, CA 94129.
Am J Clin Nutr. 1988 Feb;47(2):180-5. doi: 10.1093/ajcn/47.2.180.
Determination of body composition by measuring total-body electrical conductivity (TOBEC) is based on the principle that body fat and fat-free mass (FFM) differ in electrical properties. In humans, we are able to estimate body composition only by indirect methods, which have been used to validate the TOBEC instrument. Relationships between TOBEC and body composition were examined using direct carcass analysis of 24 pigs differing widely in body weight and composition (48-137 kg and 14-45% fat, respectively). Highly significant correlations (p less than 0.0001) were found between body conductivity and empty-body water (H2O) (r = 0.979), empty-body FFM (r = 0.980), empty-body crude protein (r = 0.962), and empty-body potassium (r = 0.949). Prediction of empty-body H2O or FFM from TOBEC had a SEE of 2.1 or 2.8 kg, respectively. Thus, the TOBEC method can predict body H2O and FFM over a wide range of body weight and fatness.
通过测量全身电导率（TOBEC）来测定身体成分是基于身体脂肪和去脂体重（FFM）在电学性质上存在差异这一原理。在人类中，我们只能通过间接方法来估计身体成分，这些方法已被用于验证TOBEC仪器。使用对24头体重和身体成分差异很大（分别为48 - 137千克和14 - 45%脂肪）的猪进行直接胴体分析，研究了TOBEC与身体成分之间的关系。发现身体电导率与胴体水分（H2O）（r = 0.979）、胴体去脂体重（r = 0.980）、胴体粗蛋白（r = 0.962）和胴体钾（r = 0.949）之间存在高度显著的相关性（p小于0.0001）。根据TOBEC预测胴体水分或去脂体重的估计标准误（SEE）分别为2.1千克或2.8千克。因此，TOBEC方法可以在很宽的体重和肥胖范围内预测身体水分和去脂体重。
