About: Body water is a(n) research topic. Over the lifetime, 3284 publication(s) have been published within this topic receiving 121643 citation(s).
Papers published on a yearly basis
TL;DR: Skinfold thicknesses at four sites – biceps, triceps, subscapular and supra-iliac – and total body density were measured on 209 males and 272 females aged from 16 to 72 years, finding it necessary to use the logarithm of skinfold measurements in order to achieve a linear relationship with body density.
Abstract: The fat content of the human body has physiological and medical importance. It may influence morbidity and mortality, it may aIter the effectiveness of drugs and anaesthetics, and it may affect the ability to withstand exposure to cold and starvation. Thus the measurement of the total body fat provides useful information. In many people, but by no means everyone, a moderately satisfactory estimate of the body fat content can be obtained from the height and weight. However, for more precise evaluation several methods are available which give a reasonably accurate measure of body fat both in normal subjects and in individuals with unusual body builds. Most of these methods are based on the assumption that the body can be considered to consist of two compartments of relatively constant composition but which are distinctly different; these compartments are: (I) the body fat, which includes the entire content of chemical fat or lipids in the body, and (2) the fat-free mass (FFM), which includes all the rest of the body apart from fat. The body fat compartment is anhydrous, contains no potassium and has a fairly constant density of about 0.90 x 103 kg/m3. The fat-free compartment on the other hand probably has a fairly constant density of about 1.10 x 103 kg/m3, a potassium content of about 68 mequiv./kg in males (about 10% less in females) and a water content of about 720 g/kg. Thus measurement of body density or of total body K or of total body water allows a calculation of the relative proportion of these two compartments in the body and therefore also of the total fat content. The accuracy of these measures, however, is limited by the variability of the composition and density of the fat-free compartment in different individuals. In particular, individuals with a relatively high or
TL;DR: Data indicate that the bioelectrical impedance technique is a reliable and valid approach for the estimation of human body composition and further validation of this method is recommended in subjects with abnormal body composition.
Abstract: A method which involves the measurement of bioelectrical resistive impedance (R) for the estimation of human body composition is described. This method is based upon the principle that the electrical conductivity of the fat-free tissue mass (FFM) is far greater than that of fat. Determinations of R were made in 37 healthy men aged 28.8 ± 7. 1 yr (mean ± SD) using an electrical impedance plethysmograph with a four electrode arrangement that introduces a painless signal (800 zA at 50 kHz) into the body. FFM was assessed by hydrodensitometry and ranged from 44.6-98. 1 kg. Total body water (TBW) determined by D2O dilution and total body potassium (TBK) from whole body counting were 50.6 ± 10.3 L and 167.5 ± 38.1 g, respectively. Test-retest correlation coefficient was 0.99 for a single R measurement and the reliability coefficient for a single R measurement over 5 days was 0.99. Linear relationships were found between R values and FFM (r = -0.86), TBW (r = -0.86), and TBK (r = -0.79). Significant (p < 0.01) increases in the correlation coefficients were observed when the predictor Ht2/R was regressed against FFM (r = 0.98), TBW (r = 0.95), and TBK (r = 0.96). These data indicate that the bioelectrical impedance technique is a reliable and valid approach for the estimation of human body composition. This method is safe, noninvasive, provides rapid measurements, requires little operator skill and subject cooperation, and is portable. Further validation of this method is recommended in subjects with abnormal body composition. Am J Clin Nutr l985;4l:8l0-8l7.
TL;DR: A table gives the percentage of the body-weight as fat from the measurement of skin-fold thickness, which was calculated to predict body fat from skinfolds with an error of about ±3.5%.
Abstract: fold thickness. A simple method of assessing quantitatively the fat content of the human body, which could be used not only in laboratories and in hospital, but in field studies and in general medical practice, would be invaluable. Methods in use at present, based on measurements of body density, body water or body potassium, can be applied only in the laboratory and usually to small numbers of subjects. Several previous papers have suggested relationships between one of the accepted methods of determining body fat and a simpler technique which could be widely applied. As early as 1921, Matiegka (1921) formulated an equation for calculating body fat from measurements of surface area and six skinfold thicknesses. Brotek & Keys (1951) were the first to use the relationship between skinfold thickness and body density for assessing fat content. The skinfolds chosen were not ideal and their formula has not been widely used. Pascale, Grossman, Sloane & Frankel (1956) in the USA produced an equation, and PaPizkovL (1961 a) in Czechoslovakia a nomogram, for predicting fat content from skinfold thicknesses. Steinkamp, Cohen, Gaffey, McKay, Bron, Siri, Sargent & Isaacs (196 j) gave predictive equations based on measurements of body circumferences and skinfold thicknesses on 167 subjects in California. The only comparable attempt on a British population, to our knowledge, is a study on twenty-four hospital patients, measurements being made of total body water and skinfold thickness (Fletcher, 1962). Information about a wide range of body types in population groups in Britain is required. The present paper describes a study on 105 young adults and 86 adolescents. By means of results from measurements by anthropometry including skinfold thicknesses and body density, an attempt has been made to formulate simple equations for the prediction of the quantity of fat in the body. The subjects were of varying body build-thin, intermediate, plump, but very few were obese.
TL;DR: It is concluded that Quetelet's formula is both a convenient and reliable indicator of obesity.
Abstract: A weight-height index of adiposity should indicate the relative fatness of subjects of differing height unless obesity is itself correlated with height. The average body fat among adult women attending a hospital outpatient clinic for obesity was 40.5 percent of body weight. The height of an unselected series of 286 of these outpatients was found to be similar to that of the general population of women of similar age, which indicates that obesity in adult women is not significantly related to height. Body composition was measured by body density, body water and body potassium in a series of 104 female and 24 male subjects aged 14-60 years. In both sexes density, water and potassium gave progressively higher estimates of body fat (kg), and there was a significant difference between the values by different methods. The average of the estimates by these three methods was taken to be the 'true' value for each individual (F kg). Regression of F/H2 on W/H2 (Quetelet's index) gave a correlation coefficient of 0.955 for women and 0.943 for men. The deviation of the body fat estimated from Quetelet's formula from the 'true' value was not much greater than that when density, water or potassium were used as a basis for estimating body fat. It is concluded that Quetelet's formula is both a convenient and reliable indicator of obesity.
TL;DR: Clinical use of BIA in subjects at extremes of BMI ranges or with abnormal hydration cannot be recommended for routine assessment of patients until further validation has proven for BIA algorithm to be accurate in such conditions.
Abstract: BIA is easy, non-invasive, relatively inexpensive and can be performed in almost any subject because it is portable. Part II of these ESPEN guidelines reports results for fat-free mass (FFM), body fat (BF), body cell mass (BCM), total body water (TBW), extracellular water (ECW) and intracellular water (ICW) from various studies in healthy and ill subjects. The data suggests that BIA works well in healthy subjects and in patients with stable water and electrolytes balance with a validated BIA equation that is appropriate with regard to age, sex and race. Clinical use of BIA in subjects at extremes of BMI ranges or with abnormal hydration cannot be recommended for routine assessment of patients until further validation has proven for BIA algorithm to be accurate in such conditions. Multi-frequency- and segmental-BIA may have advantages over single-frequency BIA in these conditions, but further validation is necessary. Longitudinal follow-up of body composition by BIA is possible in subjects with BMI 16–34 kg/m2 without abnormal hydration, but must be interpreted with caution. Further validation of BIA is necessary to understand the mechanisms for the changes observed in acute illness, altered fat/lean mass ratios, extreme heights and body shape abnormalities.
Trending Questions (10)