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Comparison of the validity of anthropometric and bioelectric impedance equations to assess body composition in adolescent girls
M. Loftin, J. Nichols, S. Going, M. Sothern, K. H. Schmitz, K. Ring, G. Tuuri and J. Stevens
Anthropometry, bioelectrical impedance and 2H2O measurements of body composition in Brazilian adolescents
J.A.D. Nogueira, T.H.M. da Costa and W.A. Coward
Validity of bioelectrical impedance for predicting fat-free mass in Chinese and Indian children
E.K. Duncan, E.C. Rush, J.S. Duncan, I. Freitas Jr, and G. Schofield
Sex-specific effects of HIV on body composition among African-Americans
J.C. Shlay, V. Barry, Y. Xiang, M. Farrough, F. Visnegarwala, J.Wang, D. Kotler and G. Bartsch for the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA)
The effect of age-related height loss on the BMI classification of older men and women
M. Visser and D.J.H. Deeg
A pilot investigation into body composition change and dietary intake during an 8-week low-carbohydrate diet in free-living obese women
R. Hiscutt, K. Hart, and H. Truby
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 1-8
M. Loftin,1 J. Nichols,2 S. Going,3 M. Sothern,4 K. H. Schmitz,5 K. Ring,6 G. Tuuri7 and J. Stevens8
1Department of Human Performance and Health Promotion, University of New Orleans, LA; 2Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA; 3Department of Nutritional Sciences, The University of Arizona, Tucson, AZ; 4School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA; 5Division of Epidemiology and Community Health, School of Public Health, The University of Minnesota, Minneapolis, MN; 6 Department of Biostatistics, The University of North Carolina at Chapel Hill; 7School of Human Ecology, Louisiana State University, Baton Rouge, LA; 8Departments of Nutrition and Epidemiology, The University of North Carolina at Chapel Hill; USA.
Objective: The purpose of this study was to examine the validity of two anthropometric and four bioelectric impedance (BIA) equations to estimate body composition from dual-energy x-ray absorptiometry (DXA) in adolescent girls of various ethnicities. The rationale for this study was to develop a prediction equation for percent body fat in a multi-ethnic, representative sample of sixth to eighth grade girls. Design: One-hundred and sixty-six girls (51 African-American, 45 non-Black Hispanic, 55 non-Hispanic Caucasian, 15 multiethnic) participated. Estimates of percent fat and fat-free mass (FFM) from six published BIA and anthropometric equations and the equation developed from this study were compared to body composition determined from DXA. An RJL Systems analyzer was used to measure BIA. Anthropometry included body weight, height, and triceps and calf skinfolds. Results: Average (± SD) age, size and body composition was as follows: age, 12.1±1.2 yrs, body mass 52.7±15.9 kg, height, 154.6±8.1 cm; DXA percent fat, 27.9±10.4; fat mass (FM), 15.6±10.2 kg; and fat free mass (FFM) 35.7±6.8 kg. No ethnic differences were found in the relationships between estimated and DXA measured body composition, with the exception of the skinfold equation. The six equations explained on average 82% of the variance in percent fat, 94% of the variance in fat mass, and 88% in fat free mass. Bland-Altman analysis indicated that none of the equations performed satisfactorily in our sample. Conclusions: The BIA and anthropometric equations were significantly related to DXA body composition parameters, however none met the criteria for cross-validation.
Keywords: body composition, girls of various ethnicities, prediction equations
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 9-15
J.A.D. Nogueira1, T.H.M. da Costa2 and W.A. Coward3
1Faculty of Health Sciences, University of Brasilia , Brazil ; 2Department of Nutrition, University of Brasilia , Brazil ; 3MRC Human Nutrition Research, Cambridge , United Kingdom .
Anthropometry and bioelectrical impedance analysis (BIA) are practical techniques to predict body composition but they may lack accuracy in adolescents because of variation in hydration, mineral and protein content of fat-free mass. Predictive equations developed in specific populations may thus produce errors when applied to other populations. Objective: To determine the validity of different body composition measurement techniques and equations in Brazilian adolescents compared to the more reliable reference technique of 2H2O dilution. Design: Body weight, height, maturation status, skinfold thickness, BIA resistance and TBW were measured in 50 boys and 54 girls (aged 11-15 y) after an overnight fast. Predictive equations for anthropometry (Boileau) and BIA (Sun, Kushner, and Lukaski) were compared to 2H2O measurements. Results: Mean (SD) age, height and weight were 13.5 (1.0) and 13.6 (1.1) years, 162.7 (11.2) and 160.6 (8.9) cm, and 53.6 (12.4) and 50.5 (11.3) kg for boys and girls, respectively. Mean BMI was in the normal range for this population. Different techniques and equations produced significant variations in body composition values. Bias (limits of agreement) for TBW between 2H2O and Sun, Kushner, Lukaski, and Boileau equations were: 0.02 (3.11), -0.67 (3.13), 0.60 (4.09), and -1.41 (2.90) in boys and -1.52 (2.95), 0.90 (2.46), -0.46 (2.47), and 1.24 (2.85) in girls, respectively. Conclusions: Some of the prediction equations tested produced valid TBW results on a group but not on an individual basis. Moreover, their validity to predict fatness in a group or individual was poor.
Key words: Deuterium oxide, total body water, maturation, body composition
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 17-25
E.K. Duncan,1 E.C. Rush,1 J.S. Duncan,1 I. Freitas Jr,2 and G. Schofield1
1Centre for Physical Activity and Nutrition Research; Faculty of Health and Environmental Sciences Auckland University of Technology, Auckland, New Zealand; 2Department of Physical Education, São Paulo State University, São Paulo, Brazil.
Objective: Despite the increasing popularity of bioelectrical impedance analysis (BIA) as a field measure of body composition, the accuracy of BIA has yet to be investigated in Chinese and Indian children. The objective of this study was to develop an equation for predicting fat-free mass (FFM) from bioimpedance measurements in New Zealand Chinese and Indian children and to compare its performance with existing equations developed in other ethnic groups. Design: FFM derived from total body water by deuterium dilution was used as the reference standard for developing a BIA-based prediction equation in 79 healthy Chinese and Indian children (39 M, 40 F) aged 5-15 years. Nineteen published equations for predicting FFM or total body water from BIA were cross-validated in this sample. Results: Using all possible subsets regression a single equation was developed that included height2/resistance and body weight as in dependent variables (R2 = 0.98; SEE = 1.49 kg; CV = 5.4%). Predicted residual error sum of squares (PRESS) analysis indicated that the equation had good potential for cross-validation in independent samples of Chinese and Indian children, with excellent predictive ability and negligible bias in each ethnic group. None of the published equations examined produced bias in FFM prediction that was statistically equivalent to zero and uncorrelated with FFM in our sample. The equation developed in this study showed excellent accuracy and precision for predicting the FFM of New Zealand Chinese and Indian children. Conclusions: Prediction equations that have been generated specifically for children of Chinese and Indian descent are recommended when using BIA to estimate the body composition of these ethnic groups.
Key words: Ethnicity, body composition, pediatric, bioimpedance, validation, regression equation.
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 27 -33
J.C. Shlay1, V. Barry2, Y. Xiang2, M. Farrough,3 F. Visnegarwala,4 J.Wang,5 D. Kotler5 and G. Bartsch2 for the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA)
1Denver Community Programs for Clinical Research on AIDS, University of Colorado Health Sciences Center, Denver, CO; 2CPCRA Statistical and Data Management Center, University of Minnesota, Minneapolis, MN; 3Wayne State University, Detroit, MI; 4Houston AIDS Research Team, Baylor College of Medicine, Houston, TX; 5Body Composition Unit of St. Lukes-Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York, NY, USA.
Background: Limited information is available on sex-specific differences in body composition among antiretroviral-naïve HIV-infected African-American (AA) persons compared to HIV-negative AAs. Objective: To compare measures of body composition among a group of antiretroviral-naïve HIV-infected AA men (N=175) and women (N=78) who participated in an NIH-funded Community Programs for Clinical Research on AIDS study to a representative sample of HIV-negative AAs (men: N=404, women: N=495) cohort from the NHANES IV (1999-2002). Design: Cross-sectional analyses of body composition using bioelectric impedance analysis and anthropometry. Results: For both men and women, HIV-infected individuals had significantly lower weight, lower body mass index, reduced fat-free mass, and lower total body fat (for women only) than the controls. Using an interaction term, we measured whether differences between HIV-infected and HIV-negative AAs varied by sex. We determined that compared to the controls, HIV-infected men had less TBF (difference: 1.9 kg vs. 6.6 kg), and had greater loss of overall fat-free mass (difference: 8.8 kg vs. 4.2 kg), and less fat-free area of the mid-arm (difference: 13.2 cm2 vs. 2.1 cm2) than HIV-infected women, while HIV-infected women had smaller waist circumferences (difference: 15.2 cm vs. 10.1 cm) and greater differences in percent fat mass (3.8 kg vs. 0.0 kg). Conclusions: This study found differences in body composition among antiretroviral-naïve AA HIV-infected men and women compared to HIV-negative controls, with HIV-infected men disproportionately having lower lean body mass while women had lower fat mass than did HIV-negative individuals. These findings contribute further to our understanding of the effects of HIV in AAs prior to the initiation of antiretroviral therapy.
Key words: body composition, bioelectrical impedance analysis, HIV infection, African-Americans, men, women.
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 35-40
M. Visser1 and D.J.H. Deeg2
1Institute of Health Sciences, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands and the Institute for Research in Extramural Medicine, VU Medical Center, Amsterdam, The Netherlands; 2Institute for Research in Extramural Medicine, VU Medical Center, Amsterdam, The Netherlands.
Age-related height loss may affect the calculation of body mass index (BMI) and subsequently the classification of under- and overweight in older men and women. Objective: To quantify the effect of using body height measured 9 years earlier instead of using current body height on the prevalence rates of under- and overweight in a population-based sample of older men and women. Design: Complete data on current, measured body height and weight (2001-02) and measured body height and weight 9 years earlier were available for 1163 men and women aged 63 to 93 years who participated in the Longitudinal Aging Study Amsterdam. Results: The mean loss of height was -0.8 ± 1.9 (mean ± SD) and -1.3 ± 1.7 cm in men and women, respectively, resulting in a mean overestimation of BMI by 0.3 ± 0.6 and 0.4 ± 0.6 kg/m2. This overestimation increased with increasing age group (P-value for trend P<0.0001) and was highest in women aged 85+ years (0.9 ± 0.7) kg/m2. When BMI was calculated using current height, 5.6% of the older men and women were classified one BMI category higher (eg overweight instead of normal weight) than when using height measured 9 years earlier. Estimates of longitudinal change in BMI during follow-up were biased when age-related height loss was not taken into account. Conclusions: The results of this study suggest a substantial overestimation of the point prevalence rates of overweight and obesity and of the longitudinal increase in BMI with aging in older men and women when ignoring the age-related height loss.
Key words: body height, height loss, body mass index, BMI, obesity, elderly
International Journal of Body Composition Research 2007 Vol. 5 No. 1: 41-44
R. Hiscutt1, K. Hart1, and H. Truby2
1Center for Nutrition, Dietetics and Food, School of Biomedical and Molecular Sciences, University of Surrey, Guildford , UK ; 2Discipline of Paediatrics and Child Health, University of Queensland , Herston , Australia .
Objective: Low-carbohydrate diets (LCD) are known to produce rapid initial weight loss which is thought to result from depletion of glycogen and water. This study aimed to elucidate the extent and nature of body composition and dietary intake changes induced by an LCD in free living obese women. Design: Overweight women (n=17) were counseled by registered dieticians to follow an LCD. At baseline and every week for 8 consecutive weeks, subjects were weighed and measured and body composition change was monitored using hand to foot bioelectrical impedance analysis. Results: After 8 weeks, average weight loss was 3.9kg ± 3.1, with 62% of this weight loss occurring during the initial 2 weeks. Body composition change demonstrated no significant fall in %fat-free mass or total body water over time but there was a significant reduction in fat mass with 69% total weight loss being body fat. Dietary intake indicated a sustained reduction in carbohydrate which was not fully compensated for by an increase in fat or protein, thus facilitating an overall dietary energy deficit. Conclusions: This study demonstrates that women who are counseled to follow an LCD can achieve weight and body fat loss in the short term without excessive intakes of protein.
Key words: Body composition, weight loss, obesity, low-carbohydrate diet.