Study Of Human Body Composition Research Articles

Steven B. Heymsfield, MD: Incoming President, The Obesity Society, 2018‐2019

Steven B. Heymsfield, MD: Incoming President, The Obesity Society, 2018‐2019

A Simple, Inexpensive and Portable Model for Teaching Human Body Composition to Undergraduate Health Science Students

The study of human body composition has several dimensions. This includes medical, anthropological, physical activity performance and aesthetic aspects. Understanding, in particular, of human body composition is very essential to medical and allied health science students. But, the teaching of this aspect to them is given little or no importance at the entry level in most situations. Body composition at two or three compartment levels that include body fat and fat free mass is adequate and appropriate for such students for a good understanding and clinical application. The teaching of this area of human body composition can be made easier, interesting and appealing by making use of a simple and economical physical model. Designing, constructing and use of such a model is presented in this communication.

History of the study of human body composition: A brief review.

This review assembles a chronology of human body composition research with the goal of exposing historical roots and identifying future potential trends. Body composition research has emerged over the past several decades as a distinct field, and for many scientists body composition is their primary investigative focus. Technological advances will likely move the field forward and, ultimately, help to expand knowledge of human body composition variability in health and disease. Am. J. Hum. Biol. 11:157-165, 1999. Copyright 1999 Wiley-Liss, Inc.

Total body lipid and triglyceride response to energy deficit: relevance to body composition models.

Although the study of human body composition is advancing rapidly, confusion still prevails regarding the molecular-level lipid component. Most molecular-level body composition models are presently based on the overall hypothesis that nontriglyceride lipids constitute an insignificant proportion of total body lipid. A single lipid or "fat" component consisting of triglycerides is thus assumed in most molecular-level body composition models. To test this hypothesis, the present study, carried out in adult rats, was designed to examine two questions: 1) What is the proportion of total lipids as triglycerides? and 2) Is this proportion constant or does it change with negative energy balance and weight loss produced by calorie restriction and increased exercise? Results indicated that with negative energy balance and weight loss there were progressive losses of total body triglyceride and lipid. The proportion of total lipids as triglyceride was 0.83 +/- 0.08 (SD) in control animals, with reductions at 2 and 9 wk of energy restriction [0.82 +/- 0.04 (P = NS vs. control) and 0.70 +/- 0.15 (P = 0.05)] and at 9 wk for energy restriction plus exercise [0.67 +/- 0.09 (P = 0.003)]. Nontriglyceride lipids comprised 2.8% of carcass weight at baseline and decreased to 2.2% by 9 wk of energy restriction and exercise (P = NS). Substantial differences were observed between body composition ratios expressed as percentages of the lipid-free body mass (LFM) and triglyceride-free body mass (TGFM); (e.g., total body water/LFM and TGFM in controls = 72.7 +/- 0.7 and 70.4 +/- 2.2, respectively; P = 0.02). These observations strongly support the existence and importance of nontriglyceride lipids as a body composition component that responds independently from storage triglycerides, with negative energy balance produced by food restriction and exercise.

Techniques used in the measurement of body composition: an overview with emphasis on bioelectrical impedance analysis

The study of human body composition is now a distinct research area consisting of three interconnected parts: the five-level model and associated rules that govern the relations between components, body-composition methodology, and biological factors that influence body composition. In this overview we summarize fundamental concepts that relate to the five-level model and body-composition methods. We show how these concepts can be used to outline the essential features needed to critically evaluate the bioelectrical impedance analysis method. Body-composition research is a rapidly expanding area and in-depth systematic evaluation of new methods is a vital aspect of the field's growth.

Magnetic resonance imaging provides new insights into the characterization of adipose and lean tissue distribution

Magnetic resonance imaging (MRI) represents a major advance in the study of human body composition and nutritional status. Measurement of whole body and regional adipose tissue (AT) distribution, quantification of lean tissue (LT) and its principal constituent skeletal muscle, and the assessment of visceral AT are among the advantages made possible by MRI. Indeed, the ability to quantify visceral AT has provided the researcher with significant insight into the complex relationships between body composition and health risk. Because there are no known health risks associated with MRI, this methodology is well suited for studying the effects of various nutritional perturbations on both AT and LT, in particular visceral AT and skeletal muscle. An overview of the historical development and current status of MRI within the context of body composition research is provided. Validation studies are reviewed, and new insights into the nature of AT and LT distribution in both sexes and the effects of weight loss on these same parameters are presented. Finally, directions for future MRI research are suggested.

Magnetic resonance imaging provides new insights into the characterization of adipose and lean tissue distribution

Magnetic resonance imaging (MRI) represents a major advance in the study of human body composition and nutritional status. Measurement of whole body and regional adipose tissue (AT) distribution, quantification of lean tissue (LT) and its principal constituent skeletal muscle, and the assessment of visceral AT are among the advantages made possible by MRI. Indeed, the ability to quantify visceral AT has provided the researcher with significant insight into the complex relationships between body composition and health risk. Because there are no known health risks associated with MRI, this methodology is well suited for studying the effects of various nutritional perturbations on both AT and LT, in particular visceral AT and skeletal muscle. An overview of the historical development and current status of MRI within the context of body composition research is provided. Validation studies are reviewed, and new insights into the nature of AT and LT distribution in both sexes and the effects of weight loss on these same parameters are presented. Finally, directions for future MRI research are suggested.

Body composition: research and clinical advances--1993 A.S.P.E.N. research workshop.

The 1993 ASPEN Research Workshop examined research and clinical advances in the study of human body composition. The workshop had two themes: (1) compartments of the body and their measurement, and (2) clinical applications of body composition measurements. There were 12 speakers of varied backgrounds who gave short lectures followed by panel discussions. Speakers explored the validity and potential uses of new body composition methodologies, including dual-energy x-ray absorptiometry, multiple frequency bioimpedance analysis, computerized axial tomography, magnetic resonance imaging, nuclear magnetic resonance spectroscopy, neutron inelastic scattering, and gamma-ray resonance. The application of these methods to chronically and acutely ill hospitalized patients was described. The study of body composition is an emerging distinct research area within the broad study of human biology. This conference provided an overview of important new advances in the study of human body composition.

Deuterium exchange in humans: effect of gender, body composition and age.

The stable isotope of water, deuterium (2H20), plays a key role in the study of human body composition, because it is often used to measure total body water, the largest component of body composition.l,2 One limitation of using this isotope to measure body water by isotope dilution, however, is that it overestimates total body water because of isotopic exchange into non-aqueous, organic compounds.1,3 Culebras and Moore have performed extensive animal work in this area and concluded that approximately 5% of hydrogen atoms in the body can exchange with non-aqueous compounds.3 However, the effect of physiological variables on the extent of hydrogen exchange in humans is not clearly established. The aim of this study was therefore to examine the effect of gender, body composition, and age on the extent of deuterium exchange in humans.KeywordsBody CompositionTotal Body WaterHydrogen ExchangeDeuterium ExchangeExchangeable HydrogenThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The five-level model: a new approach to organizing body-composition research

Body-composition research is a branch of human biology that has three interconnecting areas: body-composition levels and their organizational rules, measurement techniques, and biological factors that influence body composition. In the first area, which is inadequately formulated at present, five levels of increasing complexity are proposed: I, atomic; II, molecular; III, cellular; IV, tissue-system; and V, whole body. Although each level and its multiple compartments are distinct, biochemical and physiological connections exist such that the model is consistent and functions as a whole. The model also provides the opportunity to clearly define the concept of a body composition steady state in which quantitative associations exist over a specified time interval between compartments at the same or different levels. Finally, the five-level model provides a matrix for creating explicit body-composition equations, reveals gaps in the study of human body composition, and suggests important new research areas.

Relative expansion of extracellular fluid in obese vs. nonobese women

There is a conflict in previous studies with regard to the relation between adipose tissue mass and total body fluid distribution. This study tested the hypothesis that obesity is accompanied by an increase in the extracellular-to-intracellular fluid ratio above that observed in nonobese subjects. Extracellular fluid was evaluated in obese (n = 39) and nonobese (n = 26) healthy women, using two different dilution volumes, 35SO4 [extracellular water (ECW)] and 24NaCl [exchangeable sodium (Nae)]. Intracellular water (ICW = 3H2O dilution volume-ECW) and total body potassium (TBK; 40K whole body counting) were assumed to represent intracellular fluid. Two independent markers of relative fluid distribution were formulated as ECW/ICW and Nae/TBK. Obese and nonobese women were of similar age and height but differed in body weight and TBW by 67.7 kg and 12.9 liters, respectively. The obese women had significantly larger absolute ECW, Nae, ICW, and TBK compared with the nonobese women (all P less than 0.001). The ratios ECW/ICW and Nae/TBK were significantly higher in obese vs. nonobese women and were highly correlated with each other (r = 0.54, P less than 0.001) in the pooled group of subjects. Fluid volumes are thus increased in obese women, and the expansion is relatively greater for the extracellular compartment. These results have implications in the study of human body composition and may also account in part for the fluid-overload states that often accompany severe obesity.

Application of Electromagnetic and Sound Waves in Nutritional Assessment

Four relatively new techniques that apply electromagnetic or sound waves promise to play a major role in the study of human body composition and in clinical nutritional assessment. Computerized axial tomography, nuclear magnetic resonance, infrared interactance, and ultrasonography provide capabilities for measuring the following: total body and regional fat volume; regional skeletal muscle volume; brain, liver, kidney, heart, spleen, and tumor volume; lean tissue content of triglyceride, iron, and high-energy intermediates; bone density; and cardiac function. Each method is reviewed with regard to basic principles, research and clinical applications, strengths, and limitations.

Nuclear-based techniques for the in vivo study of human body composition. Report of an Advisory Group of the International Atomic Energy Agency.

A variety of nuclear-based techniques for the in vivo study of human body decomposition is now available for clinical diagnosis and research, and the number of centres where such work is performed is likely to grow substantially in the next few years. Their most important applications at present are in the measurement of bone mineral mass (calcium), body protein (nitrogen) and organ contents of cadmium and lead. Although still mainly used as research tools, they are already at a stage where routine applications can be justified in clinical diagnosis and occupational health monitoring. The radiation doses delivered to the subject vary according to the sensitivity and precision required, but are generally low compared with many common radiological examinations and diagnostic tests.