Accession Number : ADA186096

Title :   Validity of Impedance Predictions at Various Levels of Fatness.

Descriptive Note : Final rept.,

Corporate Author : NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA

Personal Author(s) : Hodgdon, James A. ; Fitzgerald, Patricia I.

PDF Url : ADA186096

Report Date : JUN 1986

Pagination or Media Count : 29

Abstract : There was general over-prediction of individuals having lower %BF values and under-prediction of individuals having higher %BF values using equations supplied by manufacturer of the RES measurement device. This problem of non-generalizability was not alleviated by redetermination of regression constants using the variables contained in the manufacturer's equations on this particular sample; incorporation of anthropometric variables in models involving RES and stature; and weighing of the cases to provide equal power at all percent body fat values. Subcutaneous adipose tissue mass was estimated from skinfold thickness and body surface area. The difference between this subcutaneous adipose tissue mass and total fat mass predicted from hydrodensitometry was compared with accepted values for essential fat for men and women. In this sample, over-prediction of low %BF individuals occurred at approximately the %BF value at which predicted residual fat becomes less than accepted essential fat values. This finding suggests that problems of non-generalizability of equations containing RES values may be associated with violation of the assumptions of the fixed-denisty, two-compartment model used for conversion of body density values to percent body fat values, which is the criterion measure for most equation development, rather than with the use of RES as a predictor.

Descriptors :   *ADIPOSE TISSUE, *ELECTRICAL IMPEDANCE, ANTHROPOMETRY, DENSITY, EQUATIONS, FATS, MASS, MEASURING INSTRUMENTS, MODELS, PREDICTIONS, REGRESSION ANALYSIS, RESIDUALS, SUBCUTANEOUS TISSUE, SURFACES, VALIDATION, VARIABLES, WOMEN, BODY WEIGHT.

Subject Categories : Medicine and Medical Research
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE