American Journal of Clinical Nutrition, Vol 20, 708-715, Copyright © 1967 by The American Society for Clinical Nutrition, Inc.

Body Composition of a Military Population, Fort Carson, 1963

I. Body Density, Fat, and Potassium 40

¹ From U. S. Army Medical Research and Nutrition laboratory, Fitzsimons General Hospital, Denver, Colorado

Body volumes were measured on 97 soldiers between the ages of 17 and 52 years by water displacement volumetry and corrected for respiratory gas by a nitrogen-washout technique. Total body potassium 40 was measured by a NaI crystal low level gamma radiation counter. The subjects were grouped into 5-year age increments and compositional changes were noted to occur in precent body fat and quantity of body potassium present. Body density decreased with age reflecting an increase in body fat. Total body potassium decreased with age. Both parameters varied independently of body weight and appear to be age dependent. Eight additional obese subjects were found to have the lowest body density and total body potassium values (grams of potassium per kilogram body weight). Effective ranking of body fat burdens of populations was demonstrated by body volumetry and age differences were noted from potassium-40 counting. A correlation coefficient of r = 0.731 was demonstrated between body density and body potassium (grams of potassium per kilogram body weight).