Density of fat-free body mass: relationship with race, age, and level of body fatness.
Density of fat-free body mass: relationship with race, age, and level of body fatness.
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无脂肪体重密度：与种族、年龄和身体脂肪水平的关系。
DOI：
10.1152/ajpendo.1997.272.5.e781
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Heymsfield,SB
中科院分区：
文献类型：
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作者：
Visser,M;Gallagher,D;Deurenberg,P;Wang,J;PiersonJr,RN;Heymsfield,SB
二室法假定去脂体质量密度为1.100 kg/L。本研究验证了去脂体质量密度与种族、年龄和体脂无关的假设。受试者为703名黑人和白人，年龄20-94岁，体重指数(BMI)17-35 kg/m2。使用基于氚稀释体积、水下称重的身体密度、双能X射线吸收测量仪的骨矿物质和体重的四室模型来评估身体成分。未观察到FFM密度与种族或BMI的关系。只在老年白人女性中观察到FFM密度较低的趋势。在所有组中，四室模型和水下称重之间的体脂百分比(增量脂肪)的差异为2%。种族、年龄和BMI只解释了三角洲脂肪变异的2.3(女性)和1.4%(男性)，而FFM的全身水分分数解释了77%。与目前的想法相反，这些结果表明恒定FFM密度的假设在黑人、老年人和肥胖者中是有效的。
The two-compartment body composition method assumes that fat-free body mass (FFM) has a density of 1.100 kg/l. This study tested the hypothesis that FFM density is independent of race, age, and body fatness. Subjects were 703 black and white subjects, ages 20-94 yr, with body mass index (BMI) 17-35 kg/m2. Body composition was assessed using a four-compartment model based on tritium dilution volume, body density by underwater weighing, bone mineral by dual-energy X-ray absorptiometry, and body weight. No relationship was observed between FFM density and race or BMI. A tendency was observed for a lower FFM density only in older white women. The difference in percent body fat (delta fat) between the four-compartment model and underwater weighing was < 2% for all groups. Race, age, and BMI explained only 2.3 (women) and 1.4% (men) of the variance in delta fat, whereas the total body water fraction of FFM explained 77%. In contrast to current thinking, these results show that the assumption of constant FFM density is valid in black, elderly, and obese subjects.