Kyle Ursula G, Genton Laurence, Gremion Gérald, Slosman Daniel O, Pichard Claude
Division of Clinical Nutrition, Geneva University Hospital, 1211 Geneva, Switzerland.
Clin Nutr. 2004 Feb;23(1):79-88. doi: 10.1016/s0261-5614(03)00092-x.
BACKGROUND & AIM: Regular physical activity prevents or limits weight gain, and gain in body mass index (BMI) and decreases mortality. The aims of the study in healthy adults were to determine the differences in fat-free mass index (FFMI) (kg/m(2)) and body fat mass index (BFMI) between age groups and determine the association between physical activity and FFMI and BFMI.
Caucasian men (n=3549) and women (n=3184) between 18 and 98 years, were classified as either sedentary or physically active (at least 3h per week at moderate or high-intensity level activity). FFMI and BFMI were measured by 50 kHz bioelectrical impedance analysis.
BFMI was significantly higher (P<0.05) in sedentary than physically active subjects and the differences became progressively greater with age. The physically active subjects were significantly less likely to have a low or high FFMI (logistic regression, P<0.001), and a high or very high BFMI (P<0.001), and more likely to have low BFMI (P<0.001) compared to sedentary adults. In contrast with fat-free mass, which was lower in older subjects, the height-normalized FFMI was stable with age until 74 years and lower thereafter. Significantly higher BFMIs were noted in older subjects.
Physically active subjects are less likely to have low or high FFMI, and high or very high BFMI, and more likely to have low BFMI. In contrast to common claim that fat-free mass decreases with age, we found that FFMI was stable until 74 years. The use of FFMI and BFMI permits comparison of subjects with different heights and age.
规律的体育活动可预防或限制体重增加、体重指数（BMI）上升，并降低死亡率。本研究针对健康成年人的目的是确定不同年龄组之间的去脂体重指数（FFMI，单位：kg/m²）和体脂肪质量指数（BFMI）的差异，并确定体育活动与FFMI和BFMI之间的关联。
将18至98岁的白种男性（n = 3549）和女性（n = 3184）分为久坐不动组或体育活动组（每周至少进行3小时中等强度或高强度活动）。通过50 kHz生物电阻抗分析测量FFMI和BFMI。
久坐不动的受试者的BFMI显著高于体育活动的受试者（P < 0.05），且这种差异随着年龄的增长而逐渐增大。与久坐不动的成年人相比，体育活动的受试者出现低FFMI或高FFMI（逻辑回归，P < 0.001）以及高BFMI或非常高BFMI（P < 0.001）的可能性显著更低，而出现低BFMI的可能性更高（P < 0.001）。与老年受试者中较低的去脂体重不同，身高标准化的FFMI在74岁之前随年龄保持稳定，之后则降低。老年受试者的BFMI显著更高。
体育活动的受试者出现低FFMI或高FFMI以及高BFMI或非常高BFMI的可能性更低，而出现低BFMI的可能性更高。与普遍认为去脂体重随年龄下降的观点相反，我们发现FFMI在74岁之前是稳定的。使用FFMI和BFMI可以对不同身高和年龄的受试者进行比较。
