Abstract
Computed tomography (CT) scans were made from 100 adult humans (50 males and 50 females) at five transverse sections in the trunk to measure the differences in the body composition relative to plane, sex and age. Planes of CT scans were taken at: midpoint of the sternum (E5), xiphoid (E6), upper abdomen (E7), umbilicus (E8), and lower abdomen (E10) . The body composition was divided into subcutaneous fatty layer, bone and muscle layer and body cavity. The following results were obtained: 1) The total cross-sectional area was largest at E5 and smallest at E8 in both sexes. The total area decreased with age in males. It was largest in the fifties and rapidly decreased in the sixties in females. 2) The proportion of the subcutaneous fatty layer decreased with age in males, was about constant between the thirties and fifties and decreased above the sixties in females. The proportion of subcutaneous fatty layer was largest at E8 in all ages and was larger in females than in males. The proportion of bone and muscle decreased above the sixties and was lowest in the seventies in males, but did not change with age in females. The proportion of the body cavity increased above the forties in both sexes. 3) In the E5, E6, and E7 planes in each age, and in both sexes, the proportion of body cavity was largest, and was followed by the bone and muscle layer. At E8, the proportion of bone and muscle layer was largest, and the subcutaneous fatty layer was smallest in males. In females, the proportion of subcutaneous fatty layer was largest until the fifties, and that of bone and muscle was largest above the sixties. At E10, the proportion of bone and muscle was largest in every age and was followed by subcutaneous fatty layer in the thirties in males and until the seventies in females. 4) The proportion of the subcutaneous fatty layer was greater in females than in males in each plane and every age. The proportion of bone and muscle was highly predominant in males at E5, E8 and E10, and was slightly so at E6 in each age, and was greater to that in females at E7 until the sixties. The proportion of body cavity in males was greater than that of females at E5 at every age, at E6 and E7, above the forties. At E8 and E10, there were no sex differences in body cavity proportions.
