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The accuracy of various indirect determinations of body composition : comparison with a multicomponent criterion modelWegner, Michael S. 18 July 1994 (has links)
Accurate determinations of body composition, fat mass (FM) and fat-free
mass (FFM) are of interest to scientists as well as many individuals
who serve as health and fitness practitioners. Currently, researchers and
practitioners use a variety of indirect methods to determine body
composition. Traditional methods of estimating percent body fat include
hydrostatic weighing, skinfold anthropometry and bioelectrical
impedance. Dual energy x-ray absorptiometry (DEXA), utilized most
commonly to determine bone mineral content, has recently been proposed
to be an accurate measure in the assessment of body composition. Hologic
Inc., manufacturers of the QDR-1000/W bone densitometer, have recently
developed tissue composition software which can be used to estimate
percent body fat in humans. Although the Hologic QDR-1000/W has been
extensively evaluated for its accuracy in measuring tissue composition in
"vitro", "in vivo" validation studies of body composition have been few.
Therefore, the purpose of this study was to evaluate the accuracy of the
Hologic QDR-1000/W in determining human body composition by
comparing values for percent fat from DEXA to values derived using a multicomponent criterion measure of body composition in a group of 51 women and 50 men aged 19-82 years. Additionally, it was of interest to make comparisons of percent body fat determinations between the multicomponent criterion model and hydrostatic weighing, skinfold measures and bioelectrical impedance.
All subjects completed the various body composition procedures used to estimate percent body fat: DEXA, hydrostatic weighing (2-component model), skinfold anthropometry and bioelectrical impedance. The multicomponent (4-component) criterion model procedures induded hydrostatic weighing (body density), DEXA whole body scanning (bone mineral content), and deuterium oxide (D���0) dilution in respiratory water (total body water).
Results of this study failed to reveal statistically significant mean percent body fat differences between hydrostatic weighing (2-component model) and the 4-component criterion model (25.2 �� 9.4 vs. 26.7 �� 8.4%,
p > 0.05) for all 101 subjects. However, differences in percent body fat were found between the 4-component model (26.7 �� 8.4%) and dual energy x-ray absorptiometry (23.2 �� 7.9%), skinfold anthropometry (24.0 �� 8.5%) and bioelectrical impedance (23.4 �� 7.5%).
Among women, hydrostatic weighing (2-component model), DEXA, skinfold anthropometry, and bioelectrical impedance all provided accurate estimates of percent body fat. However, each of the various indirect methods used to predict body composition underestimated percent body fat in men. / Graduation date: 1995
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Renal cell cancer : the role of physical activity and body size /Bergström, Anna, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.
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Within-day and between-day reliability of body composition by air-displacement plethysmography in the bod podSparks, Jada L. January 1999 (has links)
The purpose of this study was to determine the reliability of within-day and between-day measurements of body volume (BV), thoracic gas volume (Vtg), and body fat percentages (%fat) taken in the BOD POD. Fifty subjects (25 men, 25 women) of varying ages (20-81 yrs.), races, and body composition (2.2-51.1% fat) were tested under ideal conditions set forth by the manufacturer at the same time of day (± 3 hours) on three separate days within two weeks. On each day, testing was repeated in succession until three trials were obtained which met the manufacturer's criteria for acceptable BV and Vtg. Repeated measures ANOVA revealed no significant mean differences between the three within-day trials or for the first trial between each of the three days with the exception of between-day BV where day 1 was found to be 260 ml greater than days 2 and 3. Coefficient of variation (SD/mean* 100) and intra-class correlations were determined for each variable both within the three trials of each day and between the first trials of each of the days. For BV, the CV for the 150 cases of within-day measurements was.1 ± .01% while the between-day CV was .4 +.3%. For both within and between day BV, r = .99. The CV and correlations for Vtg was 2.8 ± 2.4% and .99 and 4.1 ± 2.6% and .98 for within-day and between-day measures, respectively. The mean absolute difference between measured Vtg and the predicted value (Vpred) from age, height, and weight was 0.471 ± 0.392 L which would result in body fat estimates that differ by 1.3 ± 0.3%. Estimates of body fat from Vpred were within +2% fat of those derived from measured Vtg values in 80% of the trials. Body fat percentage produced a within-day CV of 2.8 + 4.6% with an r = .99 and a between-day CV of 3.8 ± 5.9% with an r =.99. However, with the exclusion of 3 subjects with body fat <7%, the within-day and between-day CV decreased to 2.0 ± 1.8% and 2.7 ± 2.1%, respectively. The difference between the first two trials of each day was < 2% fat in 93% of the cases, and all 150 cases resulted in fat within + 2% in the three trials. In conclusion, these results support that BOD POD measurements of BV, Vtg, and % fat are reliable both within and between days for a wide range of adults. Also, to obtain the most reliable measurement of % fat in the BP, measuring thoracic gas volume and averaging the values obtained from two trials which agree within + 2 % fat is recommended. / School of Physical Education
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A comparison of hydrostatic weighing with other methods of determining body fatYenzer, Beverly M January 2011 (has links)
Digitized by Kansas Correctional Industries
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Transplante ovariano autólogo em diferentes sítios anatômicos de ratas ovariectomizadas /Macedo, Michelly Fernandes de. January 2011 (has links)
Orientador: Wilter Ricardo Russiano Vicente / Banca: Raimundo Alves Barrêto Júnior / Banca: Ricardo Souza Vasconcellos / Banca: Vera Fernanda Martins Hossepian de Lima / Banca: Juliana Corrêa Borges Silva / Resumo: O transplante autólogo ovariano tem despertado um crescente interesse científico devido à sua relevante contribuição em estudos reprodutivos básicos ou aplicados de animais e humanos. A presente tese foi conduzida com o objetivo de investigar de que forma o transplante autólogo ovariano nos diferentes sítios anatômicos preconizados poderia influenciar diversos aspectos orgânicos de ratas ovariectomizadas. Para tanto, 54 ratas Wistar, foram subdivididas em seis grupos, sendo dois controles de animais não-ovariectomizados e ovariectomizados (respectivamente, grupos A e B), e quatro submetidos à ovariectomia bilateral seguida do transplante autólogo ovariano para região subcapsular do rim (grupo C), tecido subcutâneo (grupo D), bolsa ovárica (grupo E) e próximo aos vasos femorais (grupo F). Foram avaliados e comparados nos grupos e tratamentos estabelecidos, aspectos cirúrgicos, anestésicos, reprodutivos, bem como, a composição corporal dos animais. De um modo geral, os sítios anatômicos forneceram condições adequadas ao desenvolvimento e crescimento folicular, com retorno ao ciclo estral após 17-19 dias em média de transplante, sendo ainda eficazes na manutenção da histomorfometria uterina e composição corporal dos animais transplantados, à exceção do grupo F. Nos grupos C, D e E, o percentual de matéria mineral foi maior que o observado nos demais, enquanto que os teores de matéria seca, extrato etéreo e proteína bruta desses grupos foram semelhantes aos do grupo A. E por fim, nos grupos C e D, foram estimadas as maiores populações foliculares dentre os animais transplantados ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The ovarian autologous transplantation has attracted an increasing scientific interest due its contribution in basic or applied reproductive studies in animals and humans. This thesis was conducted to investigate how the autologous ovarian transplantation in different anatomical sites could influence various organic aspects of ovariectomized rats. Thus, 54 Wistar rats were divided into six groups, two controls of non-ovariectomized animals and ovariectomized (respectively, groups A and B), and four submitted to bilateral ovariectomy and ovarian autologous transplantation for under kidney capsule (group C), subcutaneous tissue (group D), bursa ovarica (group E) and nearing femoral vessels (group F). In the groups and treatments were evaluated and compared, surgical aspects, anesthetics, reproductive, as well as, the body composition of animals. In general, the anatomical sites provided good conditions for development and growth follicular with return to estrus 17-19 days after transplantation, providing the maintenance of uterine histomorphometry and body composition of animals transplanted, except in the group F. In groups C, D and E, the percentage of mineral matter (ash) was higher than that observed in the others, while the dry matter, ether extract and crude protein of these groups were similar to the group A. Finally, in groups C and D, were estimated the largest follicular populations of transplanted animals. In conclusion, the autologous ovarian transplantation, when performed for under kidney capsule, subcutaneous tissue and bursa ovarica, was effective to maintenance of functions evaluated in this study, demonstrated even in some situations, results similar to or better than those observed in animals not ovariectomized / Doutor
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Effects of resistance training on total, central and abdominal adiposityShaw, BS, Shaw, I, Brown, GA 02 September 2009 (has links)
Abstract
Despite the clear benefits that resistance training might have in weight management
the effects of resistance training on adiposity in sedentary individuals are
unsubstantiated. As such, the aim of the study was to determine the effect of
resistance training on anthropometric measures of total, central and abdominal
adiposity. Twenty-five healthy, sedentary males not on an energy-restricted diet were
assigned to a non-exercising control group (CON) (n = 12) or a resistance training
group (RES) (n = 13) to determine the effect of 16 weeks of resistance training on
anthropometric measures of total, centrally located and abdominal adiposity.
Resistance training was prescribed three times weekly using eight exercises for three
sets of 15 repetitions at 60% of one-repetition maximum. Resistance training
decreased three of the six anthropometric measures of total adiposity and increased
body mass and body mass index (BMI). Resistance training had no impact on the
measures of centrally located and abdominal adiposity. Body mass and BMI should
be used with caution in risk calculations and measures of total adiposity in
individuals engaging in resistance training due to this mode of training increasing
lean mass (and thus body mass and BMI). Resistance training reduced total adiposity
but did not provide an effective stimulus to lower centrally located and abdominal
adiposity.
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Age-related differences in human total body water relative to fat-free body mass.Hewitt, Michael John. January 1991 (has links)
The objective of this investigation was to identify the appropriate isotopic fractionation factor for total body water (TBW) from ²H₂O enrichment in respiratory water vapor (RW) compared to serum (S), then to use the RW technique to estimate absolute TBW volumes and TBW relative to fat-free body mass (FFB) in three age groups (prepubescent, PP, age = 5-10 y; young adult, YA, age = 22-39 y; older adult, OA age = 65-84 y) of healthy white males and females. The effects of analytical technique (infrared spectrophotometry, IR versus isotope-ratio mass spectrometry, IRMS) and ambient relative humidity on estimates of TBW were also investigated. The composition of the FFB was estimated using a multi-component statistical model (body density, TBW and bone mineral density), and the errors associated with the traditional two-component formula for percent fat from body density were calculated. Our results demonstrated a significant (p < 0.0001) ²H₂O fractionation effect of 0.971 ± 0.005 (mean ± SEM, n = 36) for TBW from RW compared to S. Analysis by IR and IRMS were highly correlated (R² =.999) but IR values were significantly (p < 0.001) higher than IRMS. Deuterium enrichment in RW samples collected at ambient RH (∼20%) was significantly higher (Δ = 20.2 ± 4.5 ppm, mean ± SEM, p < 0.0005) than in RW samples collected at 100% RH, roughly equivalent to a 1.2 L (3.2%) difference in TBW. Total body water relative to FFB mass (W/FFB) was lower (p < 0.01) in YA males (71.0 ± 1.0%) and females (70.2 ± 1.3%) than in PP (boys = 73.1 ± 1.6%; girls = 72.2 ± 1.4%, mean ± SD). In OA, W/FFB was higher (p < 0.05) than in YA (OAM = 72.6 ± 1.1%; OAF = 72.2 ± 1.4%). The density of the FFB was 1.0996 and 1.0839 g/ml in OAM and OAF, respectively. Percent fat from density plus TBW and BMD was lower than from density alone in all groups but YA males, where it was 2.4 percent fat higher. In PP, the Siri density formula resulted in an overestimate of 5.8 ± 2.6 percent fat (mean ± SD, range = 1.4 to 13.6%). In OA females, the density formula overestimated percent fat by 4.4 ± 2.8% (range = 0 to 10.4%). In conclusion, RW corrected for isotopic fractionation will provide acceptable estimates of TBW, although the effects of analytical technique and RH should be controlled. The existence of age-related differences in FFB composition causes errors when the two-component model is used to estimate percent fat in PP and OA females.
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Influence of macronutrient preloads on appetite and metabolic parameters in liver and renal transplant recipientsRegan, Paula J. January 2003 (has links)
No description available.
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The effect of cotton clothing on percent fat measurements via air displacement plethysmography (BOD POD)Rettig, Natasha L. January 2000 (has links)
The BOD POD (BP) is a device used for determining body composition that is based on the air displacement plethysmography method. There has been little research conducted on the BP, and the main focus of the research has been on the reliability and validity of the BP. Another important area of research with the BP is the effect that different types of clothing have on the percent fat readings from the BP. To produce the most accurate results, the manufacturers recommend that subjects wear a Lycra swimsuit, however this recommendation may not be feasible for some individuals or testing sites to follow. The purpose of this study was to determine if a standard type of clothing would affect the percent fat readings from the BP in a consistent manner. Fifty subjects (25 men, 25 women) of varying ages (19 to 84 years of age) and body composition (3.4 to 53.2% fat) completed six trials (3 cotton and 3 nylon) in the BP during one testing session. With the exception of the clothing, all other recommendations by the manufacturer were followed. The comparison between the two clothing conditions was analyzed with a 2-way ANOVA (gender x clothing), frequency distribution, and the Bland-Altman method. The reliability of the measurements was analyzed by comparing the absolute differences between the three trials with cotton clothing and the three trials with nylon clothing, with intra-class correlation coefficients, and the Bland-Altman method. The results from the 2-way ANOVA revealed that the interaction effect of gender and amount of clothing was significant with the difference between nylon versus cotton being 1.1% for men and 4.8% for women. There was also a significant difference between body fat measurements with the cotton clothing (24.2 + 11.2%) and the nylon clothing (27.1 + 11.6%) when analyzed with all the subjects combined (men and women). Reliability analysis resulted in intra-class correlation coefficients of 0.9 and 0.95 within the cotton and nylon clothing trials, respectively. The comparison of the absolute differences between the cotton trials and the nylon trials showed a between-trial standard deviation of approximately 0.6 for cotton and 0.7 for nylon. In the comparison of nylon to cotton clothing results, there was a greater difference between the results for the women than for the men. The men had a lower, similar difference when comparing the two clothing conditions, whereas the women had a higher, difference that was not similar between subjects. In conclusion, this study showed that using either cotton or nylon shorts for men is acceptable, whereas for women more testing is needed to find another type of clothing to replace the Lycra swimsuit that results in consistent percent fat measurements. Also, the reliability of the percent fat readings obtained with both clothing conditions was very good. / School of Physical Education
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The effects of varying hydration conditions on air displacement plethysmography and dual energy x-ray absorptiometryGray, Rhonda Michelle January 2003 (has links)
The purpose of this study was to examine the effects of hydration on %BFADP while using %BFDEXA as the criterion measure. Twenty healthy males and females ages 20-28 participated in the study. The subjects underwent dehydration in the environmental chamber at 32°C and 50% relative humidity until a total of 3% of their body weight had been lost. Subjects were measured with ADP and DEXA at euhydration, 1%, 2%, and 3% dehydration. The results revealed significant differences between %BFADP and %BFDEXA at each level of hydration. %BFDEXA did not change due to dehydration; however, %BFADP decreased as a result of dehydration. Therefore, standardization criteria must be employed in order to assure proper hydration and accurate %BF measurements via ADP. / School of Physical Education
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