Research comparing portable body composition methods, such as bioelectrical impedance analysis (BIA), to air displacement plethysmography (ADP) is limited. We assessed reliability and validity of predicting fat-free mass (FFM) by the RJL, Omron, and Tanita BIA machines using ADP via BodPod as a criterion. FFM (kg) was assessed twice in college students (N = 77, 31 males and 46 females; age = 19.1 ± 1.2 years) using ADP, RJL, Omron, and Tanita BIAs. Reliability was assessed using analysis of variance to obtain an intraclass correlation statistic (Rxx). Validity was assessed using Pearson correlation (r) coefficient. FFM averaged 75.6 ± 9.4 kg in men and 59.8 ± 7.6 kg in women. Reliability was high in both genders RJL (Rxx = .974-.994), Omron (Rxx = .933-.993), and Tanita (Rxx = .921-.991). Validity within males was also high: RJL (r = .935), Omron (r = .942), and Tanita (r = .934), and only slightly lower in females: RJL (r = .924), Omron (r = .897), and Tanita (r = .898). The RJL, Omron, and Tanita BIA machines appear to be both reliable and valid for predicting FFM of male and female college students. Therefore, any of these three BIA devices is appropriate to use for body composition assessment in a healthy adult population.

中文翻译：

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市售低成本生物电阻抗分析的可靠性和有效性。

将便携式身体成分方法（如生物电阻抗分析（BIA））与空气体积体积描记法（ADP）进行比较的研究是有限的。我们评估了通过RJL，Omron和Tanita BIA机器使用ADP通过BodPod作为标准来预测无脂肪质量（FFM）的可靠性和有效性。使用ADP，RJL，Omron和Tanita BIA对大学生（N = 77，男31和女46；年龄= 19.1±1.2岁）进行两次FFF（千克）评估。使用方差分析评估可靠性，以获得类内相关统计量（Rxx）。使用Pearson相关系数（r）评估有效性。男性FFM平均为75.6±9.4千克，女性为59.8±7.6千克。RJL（Rxx = .974-.994），Omron（Rxx = .933-.993）和Tanita（Rxx = .921-.991）性别的可靠性均很高。男性中的有效性也很高：RJL（r = .935），欧姆龙（r = .942）和塔尼塔（r = .934），而女性仅略低：RJL（r = .924），欧姆龙（r = .897）和塔尼塔（r = .898）。RJL，Omron和Tanita BIA机器对于预测男女大学生的FFM似乎既可靠又有效。因此，这三种BIA设备中的任何一种都适合用于健康成年人群的身体成分评估。