Kinesiology & Health Science Department, Utah State University, Logan, UT, USA.
J Hum Nutr Diet. 2019 Dec;32(6):781-788. doi: 10.1111/jhn.12687. Epub 2019 Jul 23.
Novel and innovative imaging methods that rapidly estimate body fat percentage (%BF) are publicly available, yet little is known about their accuracy. The present study evaluated the test-retest reliability of a two-dimensional iPad (Apple, Inc., Cupertino, CA, USA) application (2D APP) and a three-dimensional body scanner (3D SCAN) for estimating %BF and compared both imaging methods with air displacement plethysmography (Bod Pod; Cosmed USA, Inc., Concord, CA, USA).
Seventy-nine adults (37 female, 42 male) varying widely in age [mean (SD), range] [32.9 (12.4), 18-65 years] and body mass index [25.0 (4.9), 18.2-41.8 kg m ] were measured with the Bod Pod and twice with the 3D SCAN and the 2D APP in a repeated-measures design.
Test-retest reliability was excellent for both the 2D APP (intraclass correlation = 0.993) and the 3D SCAN (intraclass correlation = 0.993) with the SEM <1% BF for both methods. Although the three methods were highly correlated with each other (r = 0.857-0.923), the mean %BF estimations were significantly different (P = 0.001). The 2D APP [19.9 (8.2)%BF] underestimated the Bod Pod value [21.9 (9.4)%BF] and the 3D SCAN [24.0 (6.8)%BF] overestimated. Additionally, the SE of estimate and total error exceeded 4% BF for both 2D APP and 3D SCAN, and both methods tended to overestimate lean participants and underestimate fat participants.
Although highly reliable, neither the 2D APP, nor the 3D SCAN provided valid estimates of %BF .
新型创新的成像方法可以快速估计体脂肪百分比（%BF），但人们对其准确性知之甚少。本研究评估了二维 iPad（苹果公司，库比蒂诺，加利福尼亚州，美国）应用程序（2D APP）和三维身体扫描仪（3D SCAN）估计%BF 的测试 - 重测可靠性，并将这两种成像方法与空气置换体描记法（Bod Pod; Cosmed USA，Inc.，康科德，加利福尼亚州，美国）进行了比较。
79 名成年人（37 名女性，42 名男性）年龄差异很大[平均值（SD），范围] [32.9（12.4），18-65 岁]和体重指数[25.0（4.9），18.2-41.8 kg m]使用 Bod Pod 进行测量，并在重复测量设计中两次使用 3D SCAN 和 2D APP 进行测量。
2D APP（组内相关系数=0.993）和 3D SCAN（组内相关系数=0.993）的测试 - 重测可靠性均非常出色，两种方法的 SEM <1% BF。尽管这三种方法彼此高度相关（r = 0.857-0.923），但平均%BF 估计值差异显著（P = 0.001）。2D APP [19.9（8.2）%BF]低估了 Bod Pod 值[21.9（9.4）%BF]，3D SCAN [24.0（6.8）%BF]高估了。此外，2D APP 和 3D SCAN 的估计 SE 和总误差均超过 4% BF，这两种方法都倾向于高估瘦参与者，低估胖参与者。
尽管高度可靠，但 2D APP 和 3D SCAN 均无法提供准确的%BF 估计值。
