Body composition of adolescent males. Part I. Total body water in normal adolescent males. Part II. Body composition of the male reference adolescent.

This study was undertaken to obtain total body water (TBW) data suitable for derivation of body composition of the typical adolescent male. TBW by the deuterium dilution method, stage of sexual development and anthropometric parameters (weight, height and triceps and subscapular skinfold thickness) were determined in 108 males between 10 and 14 years of age, whose weight and height fell between the 10th and the 90th percentile of the NCHS reference data. TBW/weight did not change significantly between 10 and 14 years, although a slight increase after age 11 years and from genital stage 2 to stage 5 was present. This indicates that body fat content decreases after 11 years and after genital stage 2, especially if the fact is taken into account that water content of fat-free body mass decreases during this age period. The ability of single anthropometric parameters to predict TBW/weight was low (subscapular skinfold thickness, r = -0.62; triceps skinfold thickness, r = -0.54; weight/height cube ratio, r = -0.48). Even with the use of various combinations of anthropometric parameters in multiple stepwise prediction equations it was not possible to explain more than 50% of the variation of TBW/weight and the high standard error of the estimate indicated large errors in prediction. Thus, body composition of normal adolescent males cannot be predicted with an acceptable degree of accuracy by anthropometric parameters. On the other hand, the deuterium dilution method using salivary water represents a noninvasive method for the determination of TBW which is quite simple and suitable for field studies.