Part 1 Data Presentation第1部分數據展示
 

表1.體重，身高，體重，腰圍和19個女大學生在碩士2男腰臀比和營養倫敦大學國王學院的2013-2014（N= 21）。在體內，身體成分只能間接測量。人體測量 - 測量身體成分的最快和最便宜的方法。

Table 1. Weight, Height, BMI, Waist Circumference and Waist-Hip Ratio of 2 Male and 19 FemaleStudents in MSc Nutrition 2013-2014 of King’s College London(N=21)

存在BMI和腰圍之間有緊密的正相關關系。從皮褶厚度測量身體脂肪百分比是與BIA的測量強烈的正相關.There exist strong and positive correlation between BMI and waist circumference.Percent body fat measured from skinfolds was strongly and positively correlated with that measured from BIA

圖3.皮褶厚度測量和BIA的體脂百分比的平均差異的奧特曼地塊

協議的限分別為-6.03％和8.65％之間，且沒有離群了近0.Paired t檢驗，這兩種方法測量身體脂肪百分比的平均差表明這兩個測量身體脂肪百分比之間無顯著差異 方法

第2部分回答這個問題：什么是這里用來測量身體脂肪量的方法的優點和缺點？簡要描述了體重定量兩金標準或高的技術方法。Figure 3. The Bland-Altman Plots of Mean Differences of Percent Body Fat between Skinfold Thickness Measurement and BIA

The limits of agreement were between -6.03% and 8.65%, and there was no outlierThe mean difference of percent body fat measured by these two methods close to 0.Paired t-test showed no significant difference between percent body fat measured by these two methods

Part 2 Answer the Question: What are the advantages and disadvantages of the methods used here to measure body fat mass? Briefly describe two gold-standard or high-technology methods for body mass quantification. 

 

In vivo, body composition can only be measured indirectly. Anthropometry -- the quickest and cheapest method to measure body composition. Anthropometric measurements (circumference measures and skinfold thickness: triceps, biceps, sub scapula, and iliac crest) have been preferred for routine clinical use. The thickness of the subcutaneous FM (fat mass) reflects a constant proportion of the total FM. The average thickness of skin folds at selected sites reflects the subcutaneous FM.Then the whole-body Density (densitometry) could be calculated by Durnin&Womersley (1974) method. Combined with total body mass, densitometry allows us to estimate the fat mass and fat-free mass using Siri’s 2-component model (1956) F= 4.95/D – 4.5 (F=body fat (%) and D=whole-body density). The errors estimating FM and FFM from BM and skin fold thickness are reported between 3 and 9%, highly depending on the experience of the observer. #p#分頁標題#e#

 

Bioimpedance analysis is a simple, inexpensive, and noninvasive body composition measurement method that based on the electrical conductive properties of the human body by measuring bioelectrical conductivity. BIA assumes that the body consists of two compartments, fat and FFM. But for very obese persons, the validity of BIA is questioned as TBW and extracellular water relative to TBW are both greater in obese subjects compared with normal-weight individuals.

 

Quantitative magnetic resonance relies on proton nuclear magnetic resonance to measure human body composition. The QMR system estimates the fat mass, lean tissue mass, free water and total body weight. It have important advantages that it provides body composition estimates with high precision and without the use of ionizing radiation and could accommodate subjects up to 250kg.

 

Dilution techniques evaluate the fat and FFM of body since fat is relatively anhydrous and 73% FFM compartment is water in healthy adults. Basic assumptions include equal distribution throughout the pool of interest and dilution is complete within a specific period of time without any loss.

 

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Reference

Basic concepts in nutrition: Body composition and its measurement e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism, Volume 3, Issue 3, June 2008, Pages 126-129. Klaas R. Westerterp.

 

Body Composition, Encyclopedia of Human Nutrition, 2005, Pages 210-220D. Gallagher, S. Chung