Validity of Impedance Predictions at Various Levels of Fatness.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA186096
Entities
People
- James A. Hodgdon
- Patricia I. Fitzgerald
Organizations
- Naval Health Research Center