Analysis of Adipose Tissue in Relation to Body Weight Loss in Man

¹ From the Biochemistry Branch, U.S. Naval Radiological Defense Laboratory, San Francisco, California

Changes in the composition of the whole body and of subcutaneous adipose tissue have been studied during weight reduction in two human subjects. The whole body lost tissues ranging in density from 0.92 to 0.96 gm/ml at body temperature, consisting of 55–85% fat. The adipose tissue fat contents fell during weight loss from 80–85% to 65–80% of the whole tissue, or by about 50% when related to the dry, defatted residue. The densities of fat depots increased, therefore, as a result of the excess loss of tissue fat. Adipose tissue densities calculated from chemical composition agreed well with the values obtained by indirect determination. From these observations it is concluded that while adipose tissues probably contributed the greatest portion of the fat and body weight loss during weight reduction, other soft tissues also contribute significantly to the body weight decrease by losing nonfat components. Adipose tissue components are not lost uniformly during body weight loss in the human.