Bemben M G, Massey B H, Bemben D A, Boileau R A, Misner J E
Department of Kinesiology, University of Illinois at Urbana-Champaign 61801, USA.
Med Sci Sports Exerc. 1995 Feb;27(2):264-9.
Fat-free body mass has been reported to decline by 30% between the ages of 30 and 70 yr, whereas body weight increases until age 50 yr. This study examined the age-related patterns in body composition, specifically its two components, fat-free body mass and fat mass, in 157 men aged 20-79 yr. Total body composition was assessed by hydrodensitometry and subcutaneous fat was measured with skinfolds. Approximately 15 men were tested in each of the 12 5-yr age groups (20-24, 25-29, 30-34, ... 75-79 yr). Body density, as determined by underwater weighing, was lower successively from the youngest to oldest age groups; men below age 40 yr had significantly higher (P < 0.01) body densities than the older men. Although there was a gradual decline in fat-free body mass with increasing age, there was not a significant age group effect until age 70 yr. Fat mass gradually increased with increasing age; men above age 40 yr had significantly higher (P < 0.01) total body fat when compared to the younger men. Subcutaneous body fat was similar at the distal limb locations for each age group; however, the proximal trunk locations, especially the abdomen, demonstrated significantly (P < 0.01) higher skinfold thicknesses with increasing age. In conclusion, fat-free body mass was maintained to a later age than previously reported; thus, the age-related decline in body density could be attributed to an age-related increase in body fat.
据报道，无脂肪体重在30至70岁之间下降了30%，而体重在50岁之前会增加。本研究调查了157名年龄在20至79岁之间男性的身体成分随年龄变化的模式，特别是其两个组成部分，即无脂肪体重和脂肪量。通过水下密度测量法评估全身成分，并用皮褶厚度测量皮下脂肪。在12个5岁年龄组（20 - 24岁、25 - 29岁、30 - 34岁、……75 - 79岁）中，每个年龄组大约测试15名男性。通过水下称重确定的身体密度从最年轻到最年长的年龄组依次降低；40岁以下的男性身体密度显著高于（P < 0.01）年长男性。尽管无脂肪体重随着年龄增长逐渐下降，但直到70岁才出现显著的年龄组效应。脂肪量随着年龄增长逐渐增加；40岁以上的男性与年轻男性相比，全身脂肪显著更高（P < 0.01）。每个年龄组在四肢远端部位的皮下脂肪相似；然而，近端躯干部位，尤其是腹部，随着年龄增长皮褶厚度显著更高（P < 0.01）。总之，无脂肪体重维持到比先前报道的年龄更晚；因此，与年龄相关的身体密度下降可归因于与年龄相关的身体脂肪增加。
