scholarly journals Techniques for the study of energy balance in man

2003 ◽  
Vol 62 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Marinos Elia ◽  
Rebecca Stratton ◽  
James Stubbs
Keyword(s):  
Body Composition ◽  
Measurement Error ◽  
Energy Balance ◽  
Energy Intake ◽  
Dual Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Whole Body ◽  
X Ray ◽  
Body Segments

Energy balance can be estimated in tissues, body segments, individual subjects (the focus of the present article), groups of subjects and even societies. Changes in body composition in individual subjects can be translated into changes in the energy content of the body, but this method is limited by the precision of the techniques. The precision for measuring fat and fat-free mass can be as low as 0.5 kg when certain reference techniques are used (hydrodensitometry, air-displacement plethysmography, dual-energy X-ray absorptiometry), and approximately 0.7 kg for changes between two time points. Techniques associated with a measurement error of 0.7 kg for changes in fat and fat-free mass (approximately 18MJ) are of little or no value for calculating energy balance over short periods of time, but they may be of some value over long periods of time (18 MJ over 1 year corresponds to an average daily energy balance of 70 kJ, which is <1% of the normal dietary energy intake). Body composition measurements can also be useful in calculating changes in energy balance when the changes in body weight and composition are large, e.g. >5–10 kg. The same principles can be applied to the assessment of energy balance in body segments using dual-energy X-ray absorptiometry. Energy balance can be obtained over periods as short as a few minutes, e.g. during measurements of BMR. The variability in BMR between individuals of similar age, weight and height and gender is about 7–9%, most of which is of biological origin rather than measurement error, which is about 2%. Measurement of total energy expenditure during starvation (no energy intake) can also be used to estimate energy balance in a whole-body calorimeter, in patients in intensive care units being artificially ventilated and by tracer techniques. The precision of these techniques varies from 1 to 10%. Establishing energy balance by measuring the discrepancy between energy intake and expenditure has to take into consideration the combined validity and reliability of both components. The measurement error for dietary intake may be as low as 2–3% in carefully controlled environments, in which subjects are provided only with certain food items and bomb calorimetry can be undertaken on duplicate samples of the diet. Reliable results can also be obtained in hospitalised patients receiving enteral tube feeding or parenteral nutrition as the only source of nutrition. Unreliability increases to an unknown extent in free-living subjects eating a mixed and varied diet; thus, improved methodology is needed for the study of energy balance.

scholarly journals Estimation of body composition from bioelectrical impedance of body segments: Comparison with dual-energy X-ray absorptiometry

1993 ◽  
Vol 69 (3) ◽  
pp. 645-655 ◽  
Author(s):  
S. P. Stewart ◽  
P. N. Bramley ◽  
R. Heighton ◽  
J. H. Green ◽  
A. Horsman ◽  
...  
Keyword(s):  
Body Composition ◽  
Muscle Mass ◽  
Bioelectrical Impedance ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Whole Body ◽  
Simple Method ◽  
Creatinine Excretion ◽  
X Ray ◽  
Body Segments

In twenty-eight healthy subjects, ten men and eighteen women, with a range in body mass index (BMI) of 17.9–31.6 kg/m2 and an age range 20–60 years, body composition was estimated by dual-energy X-ray absorptiometry (DEXA), skinfold anthropometry (SFA) and bioelectrical impedance analysis (BIA) of the ‘whole body’and body segments. In thirteen subjects muscle mass was also estimated by 24 h urinary creatinine excretion. The relationship between fat-free mass (FFM) determined by DEXA and the impedance index of each body segment (calculated as Iength2/impedance (Z)) was analysed. The strongest correlation was between FFM (DEXA) and height2/‘whole-body’Z (Zw) (r 0.97 for the combined sexes, standard error of estimate (SEE) 2.72 kg). Separate prediction equations were found to be necessary for males and females when estimating FFM from BIA measurement of the arm (for men, r 0.93, SEE 1.98 kg; for women, r 0.75, SEE 2.87 kg). Muscle mass derived from 24 h creatinine excretion showed weak correlation with FFM (DEXA) (r 0.57, P = 0.03) and no correlation with FFM (SFA). FFM (SFA) correlated well with both FFM (DEXA) (r 0.96, SEE = 3.12 kg) and with height2/Zw (r 0.92, SEE 4.52 kg). Measurement of the impedance of the arm offers a simple method of assessing the composition of the whole body in normal individuals, and it appears comparable with other methods of assessment.

scholarly journals Comparison of Dual-Energy X-Ray Absorptiometry (DXA) versus a Multi-frequency Bioelectrical Impedance (InBody 770) Device for Body Composition Assessment after a 4-Week Hypoenergetic Diet

2019 ◽  
Vol 4 (2) ◽  
pp. 23 ◽  
Author(s):  
Antonio ◽  
Kenyon ◽  
Ellerbroek ◽  
Carson ◽  
Burgess ◽  
...  
Keyword(s):  
Body Composition ◽  
Energy Intake ◽  
Body Fat ◽  
Fat Mass ◽  
Bioelectrical Impedance ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Percent Body Fat ◽  
Men And Women ◽  
X Ray

The purpose of this investigation was to compare two different methods of assessing body composition (i.e., a multi-frequency bioelectrical impedance analysis (MF-BIA) and dual-energy x-ray absorptiometry (DXA)) over a four-week treatment period in exercise-trained men and women. Subjects were instructed to reduce their energy intake while maintaining the same exercise regimen for a period of four weeks. Pre and post assessments for body composition (i.e., fat-free mass, fat mass, percent body fat) were determined via the MF-BIA and DXA. On average, subjects reduced their energy intake by ~18 percent. The MF-BIA underestimated fat mass and percentage body fat and overestimated fat-free mass in comparison to the DXA. However, when assessing the change in fat mass, fat-free mass or percent body fat, there were no statistically significant differences between the MF-BIA vs. DXA. Overall, the change in percent body fat using the DXA vs. the MF-BIA was −1.3 ± 0.9 and −1.4 ± 1.8, respectively. Our data suggest that when tracking body composition over a period of four weeks, the MF-BIA may be a viable alternative to the DXA in exercise-trained men and women.

Techniques for Undertaking Dual-Energy X-Ray Absorptiometry Whole-Body Scans to Estimate Body Composition in Tall and/or Broad Subjects

2012 ◽  
Vol 22 (5) ◽  
pp. 313-322 ◽  
Author(s):  
Alisa Nana ◽  
Gary J. Slater ◽  
Will G. Hopkins ◽  
Louise M. Burke
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
The Body ◽  
Whole Body ◽  
Whole Body Scan ◽  
Body Scan ◽  
Physically Active ◽  
X Ray ◽  
Scanning Area ◽  
Dxa Scans

Dual-energy X-ray absorptiometry (DXA) is becoming a popular tool to measure body composition, owing to its ease of operation and comprehensive analysis. However, some people, especially athletes, are taller and/or broader than the active scanning area of the DXA bed and must be scanned in sections. The aim of this study was to investigate the reliability of DXA measures of whole-body composition summed from 2 or 3 partial scans. Physically active young adults (15 women, 15 men) underwent 1 whole-body and 4 partial DXA scans in a single testing session under standardized conditions. The partial scanning areas were head, whole body from the bottom of the chin down, and right and left sides of the body. Body-composition estimates from whole body were compared with estimates from summed partial scans to simulate different techniques to accommodate tall and/or broad subjects relative to the whole-body scan. Magnitudes of differences in the estimates were assessed by standardization. In simulating tall subjects, summation of partial scans that included the head scan overestimated whole-body composition by ~3 kg of lean mass and ~1 kg of fat mass, with substantial technical error of measurement. In simulating broad subjects, summation of right and left body scans produced no substantial differences in body composition than those of the whole-body scan. Summing partial DXA scans provides accurate body-composition estimates for broad subjects, but other strategies are needed to accommodate tall subjects.

scholarly journals Energy intake, physical activity and body weight: a simulation model

1995 ◽  
Vol 73 (3) ◽  
pp. 337-347 ◽  
Author(s):  
Klaas R. Westerterp ◽  
Jeroen H. H. L. M. Donkers ◽  
Elisabeth W. H. M. Fredrix ◽  
Piet oekhoudt
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Body Weight ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Dietary Intake ◽  
Energy Intake ◽  
Relative Size ◽  
The Body ◽  
Fat Free Mass

In adults, body mass (BM) and its components fat-free mass (FFM) and fat mass (FM) are normally regulated at a constant level. Changes in FM and FFM are dependent on energy intake (EI) and energy expenditure (EE). The body defends itself against an imbalance between EI and EE by adjusting, within limits, the one to the other. When, at a given EI or EE, energy balance cannot be reached, FM and FFM will change, eventually resulting in an energy balance at a new value. A model is described which simulates changes in FM and FFM using EI and physical activity (PA) as input variables. EI can be set at a chosen value or calculated from dietary intake with a database on the net energy of foods. PA can be set at a chosen multiple of basal metabolic rate (BMR) or calculated from the activity budget with a database on the energy cost of activities in multiples of BMR. BMR is calculated from FFM and FM and, if necessary, FFM is calculated from BM, height, sex and age, using empirical equations. The model uses existing knowledge on the adaptation of energy expenditure (EE) to an imbalance between EI and EE, and to resulting changes in FM and FFM. Mobilization and storage of energy as FM and FFM are functions of the relative size of the deficit (EI/EE) and of the body composition. The model was validated with three recent studies measuring EE at a fixed EI during an interval with energy restriction, overfeeding and exercise training respectively. Discrepancies between observed and simulated changes in energy stores were within the measurement precision of EI, EE and body composition. Thus the consequences of a change in dietary intake or a change in physical activity on body weight and body composition can be simulated.

Acute Feeding Has Minimal Effect on the Validity of Body Composition and Metabolic Measures: Dual Energy X-ray Absorptiometry and a Multi-compartment Model

2021 ◽  
pp. 1-39
Author(s):  
Abbie E. Smith-Ryan ◽  
Gabrielle J. Brewer ◽  
Lacey M. Gould ◽  
Malia N.M. Blue ◽  
Katie R. Hirsch ◽  
...  
Keyword(s):  
Body Composition ◽  
Measurement Error ◽  
Fat Mass ◽  
Total Error ◽  
Resting Metabolic Rate ◽  
Compartment Model ◽  
Total Sample ◽  
Dual Energy ◽  
Fat Free Mass ◽  
X Ray

Abstract Understanding the effects of acute feeding on body composition and metabolic measures is essential to the translational component and practical application of measurement and clinical use. To investigate the influence of acute feeding on the validity of dual energy x-ray absorptiometry (DXA), a four-compartment model (4C), and indirect calorimetry metabolic outcomes, 39 healthy young adults (n=19 females; age: 21.8± 3.1 yrs, weight; 71.5 ± 10.0 kg) participated in a randomized cross-over study. Subjects were provided one of four randomized meals on separate occasions (high carbohydrate, high protein, ad libitum or fasted baseline) prior to body composition and metabolic assessments. Regardless of macronutrient content, acute feeding increased DXA percent body fat (%fat) for the total sample and females [average constant error (CE):-0.30%; total error (TE): 2.34%), although not significant (p=0.062); the error in males was minimal (CE: 0.11%; TE: 0.86%). DXA fat mass (CE: 0.26 kg; TE: 0.75 kg), lean mass (CE: 0.83 kg; TE: 1.23 kg) were not altered beyond measurement error for the total sample. 4C %fat was significantly impacted from all acute feedings (avg CE: 0.46%; TE: 3.7%). 4C fat mass (CE: 0.71 kg; TE: 3.38 kg) and fat-free mass (CE: 0.55 kg; TE: 3.05 kg) exceeded measurement error for the total sample. Resting metabolic rate was increased for each feeding condition (TE: 398.4 kcal/d). Standard pre-testing fasting guidelines may be important when evaluating DXA and 4C %fat, whereas additional DXA variables (FM, LM) may not be significantly impacted by an acute meal. Measuring body composition via DXA under less stringent pre-testing guidelines may be valid and increase feasibility of testing in clinical settings.

Physical Activity, Media Time, and Body Composition in Young Children

2006 ◽  
Vol 3 (2) ◽  
pp. 200-209 ◽  
Author(s):  
Kate A. Heelan ◽  
Joey C. Eisenmann
Keyword(s):  
Physical Activity ◽  
Body Mass Index ◽  
Body Composition ◽  
Young Children ◽  
Body Fat ◽  
Dual Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Computer Usage ◽  
X Ray

Background:It is uncertain as to whether physical activity (PA) may influence the body composition of young children.Purpose:To determine the association between PA, media time, and body composition in children age 4 to 7 y.Methods:100 children (52 girls, 48 boys) were assessed for body-mass index (BMI), body fat, fat mass (FM), and fat-free mass using dual energy x-ray absorbtiometryptiometry (DXA). PA was monitored using accelerometers and media time was reported by parental proxy.Results:In general, correlations were low to moderate at best (r < 0.51), but in the expected direction. Total media time and TV were significantly associated with BMI (r = 0.51, P < 0.05) and FM (r = 0.29 to 0.30, P < 0.05) in girls. In boys, computer usage was significantly associated with FM in boys (r = 0.31, P < 0.05).Conclusion:The relatively low correlations suggest that other factors may influence the complex, multi-factorial body composition phenotype of young children.

MO047COMPARISON BETWEEN DUAL-ENERGY X-RAY ABSORPTIOMETRY AND BIOELECTRICAL IMPEDANCE FOR BODY COMPOSITION MEASUREMENTS IN ADULTS WITH CHRONIC KIDNEY DISEASE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Natália Tomborelli Bellafronte ◽  
Lorena Vega-Piris ◽  
Paula Garcia Chiarello ◽  
Guillermina Barril Cuadrado
Keyword(s):  
Chronic Kidney Disease ◽  
Body Composition ◽  
Peritoneal Dialysis ◽  
Renal Transplantation ◽  
Bioelectrical Impedance ◽  
Total Sample ◽  
Dual Energy ◽  
Error Tolerance ◽  
Whole Body ◽  
X Ray

Abstract Background and Aims Chronic kidney disease (CKD) patients frequently have an altered body composition driven by metabolic disorders from the uremic syndrome that usually leads to increased protein catabolism, with obesity and muscle impairment being common conditions associated with worse clinical prognosis and high mortality rates. Therefore, with increased mortality and disability rates of CKD patients in the last quarter of a century and the association of a poor body composition with low survival, routine and longitudinal assessment of body composition could improve clinical outcomes. Due to limited availability of reference methods to assess nutritional status, alternative methods are used. In view of the above, our goal was to evaluate the agreement between multifrequency bioelectrical impedance spectroscopy (BIS) and Dual-energy X-ray Absorptiometry (DXA) for assessment of body composition in CKD. Method Cross-sectional and prospective analyses by DXA (Hologic, GE®) and BIS (BCM, Fresenius Medical Care®) in whole-body (BISWB) and segmental (BISSEG) protocols were performed in CKD non-dialysis-dependent, hemodialysis and peritoneal dialysis (for at least 3 months), and renal transplantation (for at least 6 months) adult (18 ≤ age ≤ 60 years old) patients. Measurements were performed consecutively by the same professional after an 8-hour fast, drainage of the peritoneal dialysate and just after the midweek hemodialysis session. Intraclass correlation coefficient (ICC) and Bland-Altman plots were evaluated for agreement analysis in group and individual levels, respectively; linear regression analysis was performed for bias assessment and development of new equations; ROC curve was constructed for diagnosis of inadequate error tolerance (DXA - BIS &gt; ± 2kg). Results A total of 266 patients were included: 137 men (M) and 129 women (W); 81 were in non-dialysis-dependent treatment, 83 in hemodialysis, 24 in peritoneal dialysis, and 80 had renal transplantation. Total sample had a mean age of 47 ± 10 years old. CKD was secondary to systemic arterial hypertension in 29% of the total sample, to glomerulonephritis in 25%, to diabetes mellitus in 10%, to polycystic kidney in 7%, to glomerulosclerosis and systemic syndromes in 8%, and to other causes and unknown etiology in 20%. Fourteen patients (4 M and 10 W) were in automated and 9 (4 M and 5 W) in continuous ambulatory PD. KTx was by living donor in 18 (14 M and 4 W) and by deceased donor in 63 (34 M and 29 W) patients. The agreement with DXA was greater for BISWB than BISSEG; for fat mass (FM) (ICC in M = 0.89; ICC in W = 0.93) than for fat free mass (FFM) (ICC in M = 0.57; ICC in W = 0.52). Bland-Altman plots showed high limits of agreement (FFM: from -9.51 to 15.64kg; FM: from -7.71 to 7.32kg) with greater bias for FFM as muscular mass increases and for FM in extremes of body fat. The agreement was lower when using the prospective data (body change analysis) (ICC for FFM in M = 0.20; ICC for FFM in W = 0.49; ICC for FM in M = 0.46; ICC for FM in W = 0.58). The factors that interfered in bias between methods were extra to intracellular water ratio (ECW/ICW), body mass index, fat mass index, waist circumference, resistance and reactance (adjusted r2 for FFM = 0.90; r2 for FM = 0.87). FFM had poorer agreement in the last tertile of ECW/ICW sample (ICC in M = 0.69, 0.68 and 0.51; ICC in W = 0.71, 0.74 and 0.38 for first, second and third tertiles, respectively). An ECW/ICW cut-off point of &gt; 0.725 for inadequate error tolerance was determined. New prediction equations for FFM (r2 = 0.91) and FM (r2 = 0.89) presented adequate error tolerance in 55% and 63% in the validation sample compared to 30% and 39% of the original equation, respectively. Conclusion For body composition evaluation in CKD, BIS applied using the whole-body protocol, in normal hydration CKD patients is as reliable as DXA; BIS must be used with caution among overhydrated patients with ECW/ICW &gt; 0.725. The newly developed equations are indicated for greater precision.

In vivo assessment of body composition and growth potential of modern broiler using dual-energy X-ray absorptiometry

2020 ◽  
Vol 60 (16) ◽  
pp. 1959
Author(s):  
Camila Angelica Gonçalves ◽  
Nilva Kazue Sakomura ◽  
Miryelle Freire Sarcinelli ◽  
Letícia Graziele Pacheco ◽  
Letícia Soares ◽  
...  
Keyword(s):  
Body Composition ◽  
Growth Rates ◽  
Dual Energy ◽  
The Body ◽  
Growth Potential ◽  
Chemical Components ◽  
Potential Growth ◽  
X Ray ◽  
Growing Period

Context Genetic improvements in modern strains have led to continuous increments in broiler growth rates, which, as a consequence, have resulted in higher economic returns for broiler producers over the last decades. Aim The present study was conducted to characterise the potential growth of the body and feathers of Cobb 500, Hubbard Flex and Ross 308 male and female broilers, as well as to assess the changes in chemical composition that occur up to 16 weeks of age. Methods Birds were fed isoenergetic diets divided in four phases and formulated to marginally exceed the nutritional requirements of the strains throughout the growing period. They were maintained in a controlled environment so as not to limit growth. A dual energy X-ray absorptiometry (DXA) scanner was used to follow the in vivo body composition of 12 broilers of each strain and sex (total of 72 broilers), and the feather weight and composition was determined in four birds of each strain and sex selected at intervals during the growing period (total of 288 broilers) through comparative slaughter with later chemical analysis. Key results Parameters of Gompertz growth curve to describe the strains were estimated for body and feather weight as well as for the growth of their chemical components. Conclusion Differences in the growth rates between strains were evident, indicating the possible differences in selection methods used by geneticists in the different breeding companies. These genetic parameters would explain part of the variation on broiler´s performance which impacts on the way they should be fed and housed during growth. Implications The accurate description of genetic growth potential is useful information to be associated with factorial models that predict nutritional and feed intake requirements of birds. The main advantage of DXA technology is to decrease the variation of body deposition on the Gompertz model, resulting from the use of the same bird throughout its life. Despite the speed of obtaining chemical values of the body, the method is unsuitable for measuring the growth of feathers, which is also important data to be collected and related to the broiler strains.

Body composition and dietary intake in patients with head and neck cancer during radiotherapy: a longitudinal study

2020 ◽  
pp. bmjspcare-2020-002359
Author(s):  
Bing Zhuang ◽  
Lichuan Zhang ◽  
Yujie Wang ◽  
Yiwei Cao ◽  
Yian Shih ◽  
...  
Keyword(s):  
Body Composition ◽  
Head And Neck Cancer ◽  
Dietary Intake ◽  
Head And Neck ◽  
Energy Intake ◽  
Neck Cancer ◽  
High Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Prospective Longitudinal

ObjectivesTo investigate the body composition and dietary intake in the patients with head and neck cancer (HNC) during radiotherapy (RT), and explore the relationship between them.MethodsThis was a prospective, longitudinal observational study. Adult patients with HNC undergoing RT between March 2017 and August 2018 were recruited. Patients’ body compositions were evaluated by bioelectrical impedance analysis, and dietary intake was recorded by 24-hour dietary recall at three time points, including baseline (T1), mid-treatment (T2) and post-treatment (T3). Patients were divided into low, middle and high energy intake groups based on the average daily energy intake (DEI). Changes in body weight (BW), fat mass (FM), fat-free mass (FFM) and skeletal muscle mass (SMM) among these three groups were compared.ResultsFrom T1 to T3, the median loss of patients’ BW, FM, FFM and SMM was 4.60, 1.90, 2.60 and 1.50 kg, respectively. The loss of BW was more dramatic from T2 to T3 than that from T1 to T2. BW loss was mainly contributed by SMM loss from T1 to T2 and by FM loss from T2 to T3. Meanwhile, patients’ dietary intake reduced during treatment. High DEI group had a significantly attenuated loss of patients’ BW, FFM, SMM and FM compared with the low DEI group.ConclusionPatients’ BW, FM, FFM and SMM all significantly reduced, especially from T2 to T3, with decreased DEI during RT, which stresses the importance of nutrition intervention during the whole course of RT.

Reliability and validity of body composition measures in female athletes

1999 ◽  
Vol 87 (3) ◽  
pp. 1114-1122 ◽  
Author(s):  
Willa C. Fornetti ◽  
James M. Pivarnik ◽  
Jeanne M. Foley ◽  
Justus J. Fiechtner
Keyword(s):  
Body Composition ◽  
Near Infrared ◽  
Female Athletes ◽  
Reliability And Validity ◽  
Bioelectrical Impedance ◽  
Single Equation ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Prediction Errors ◽  
X Ray

The purpose of this investigation was to determine the reliability and validity of bioelectrical impedance (BIA) and near-infrared interactance (NIR) for estimating body composition in female athletes. Dual-energy X-ray absorptiometry was used as the criterion measure for fat-free mass (FFM). Studies were performed in 132 athletes [age = 20.4 ± 1.5 (SD) yr]. Intraclass reliabilities (repeat and single trial) were 0.987–0.997 for BIA (resistance and reactance) and 0.957–0.980 for NIR (optical densities). Validity of BIA and NIR was assessed by double cross-validation. Because correlations were high ( r = 0.969–0.983) and prediction errors low, a single equation was developed by using all 132 subjects for both BIA and NIR. Also, an equation was developed for all subjects by using height and weight only. Results from dual-energy X-ray absorptiometry analysis showed FFM = 49.5 ± 6.0 kg, which corresponded to %body fat (%BF) of 20.4 ± 3.1%. BIA predicted FFM at 49.4 ± 5.9 kg ( r = 0.981, SEE = 1.1), and NIR prediction was 49.5 ± 5.8 kg ( r = 0.975, SEE = 1.2). Height and weight alone predicted FFM at 49.4 ± 5.7 kg ( r = 0.961, SEE = 1.6). When converted to %BF, prediction errors were ∼1.8% for BIA and NIR and 2.9% for height and weight. Results showed BIA and NIR to be extremely reliable and valid techniques for estimating body composition in college-age female athletes.

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