留学生essay-人体测量

Part 1 Data Presentation第1部分数据展示
 

表1.体重，身高，体重，腰围和19个女大学生在硕士2男腰臀比和营养伦敦大学国王学院的2013-2014（N= 21）。在体内，身体成分只能间接测量。人体测量 - 测量身体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和腰围之间有紧密的正相关关系。从皮褶厚度测量身体脂肪百分比是与BIA的测量强烈的正相关.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

图3.皮褶厚度测量和BIA的体脂百分比的平均差异的奥特曼地块

协议的限分别为-6.03％和8.65％之间，且没有离群了近0.Paired t检验，这两种方法测量身体脂肪百分比的平均差表明这两个测量身体脂肪百分比之间无显著差异 方法

第2部分回答这个问题：什么是这里用来测量身体脂肪量的方法的优点和缺点？简要描述了体重定量两金标准或高的技术方法。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#分页标题#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