School of Education, Syracuse University, Syracuse, NY, 13244, USA.
University of North Carolina Wilmington, Wilmington, NC, 28403, USA.
Clin Nutr. 2020 Dec;39(12):3836-3838. doi: 10.1016/j.clnu.2020.03.037. Epub 2020 Apr 4.
BACKGROUND & AIMS: To assess the influence of acute water ingestion on body composition analyses via Dual-Energy X-Ray Absorptiometry (DXA).
One hundred (44 females; 56 males; Age = 24.2 ± 6.7 yrs; Height = 175.8 ± 12.1 cm; Body Mass = 76.1 ± 16.5 kg) volunteers took part in this study. Participants underwent an initial DXA scan. Immediately following the DXA scan, each participant consumed 500 ml of water. Participants body mass was assessed again and immediately completed a second DXA scan. Total body fat mass, fat free mass, and percent body fat were quantified. Paired sample t-test and Pearson correlations were utilized to determine mean differences and the relationship between initial and secondary measures.
Paired sample t-test analyses revealed significant a increase in body mass of 0.46 ± 0.1 kg [t(99) = 42.6, p < .0001]. There were no significant changes in fat mass (-10.6 ± 493.4g). In contrast, there was a significant increase in lean mass (524.9 ± 615.1g) [t(99) = 8.5, p < .001]. Overall, there was a significant decrease in percent body fat of -0.16% [t(99) = 2.4, p = .02].
Results indicate that acute water ingestion before a DXA analysis will significantly influence body composition. More precisely, acute ingestion of 500 ml of water will significantly inflate fat free mass as well as lower percent body fat. While the values were of small magnitude, these results highlight the importance of the control of liquid ingestion prior to DXA scans for body composition measurement.
通过双能 X 射线吸收法（DXA）评估急性饮水对身体成分分析的影响。
100 名志愿者（44 名女性；56 名男性；年龄=24.2±6.7 岁；身高=175.8±12.1cm；体重=76.1±16.5kg）参与了这项研究。参与者首先进行了一次 DXA 扫描。在 DXA 扫描后立即饮用 500ml 水。再次测量参与者的体重，然后立即进行第二次 DXA 扫描。定量分析总体体脂量、去脂体重和体脂百分比。采用配对样本 t 检验和 Pearson 相关分析来确定初始和二次测量之间的均值差异和关系。
配对样本 t 检验分析显示，体重显著增加 0.46±0.1kg [t(99)=42.6，p<0.0001]。脂肪量没有显著变化（-10.6±493.4g）。相反，瘦体重显著增加（524.9±615.1g）[t(99)=8.5，p<0.001]。总体而言，体脂百分比显著下降了-0.16%[t(99)=2.4，p=0.02]。
结果表明，在 DXA 分析前急性饮水会显著影响身体成分。更具体地说，急性摄入 500ml 水会显著增加去脂体重并降低体脂百分比。虽然这些数值的幅度较小，但这些结果强调了在 DXA 扫描前控制液体摄入对身体成分测量的重要性。
