Hydrostatic Weighing Research Articles

BUOYANCY ASSESSED WITH FLOATING TESTS AND UNDERWATER WEIGHING. A PILOT STUDY

The aim of the present study was to compare the buoyancy assessed by floating tests with the buoyancy calculated using the variables measured during underwater weighing. We also aimed to evaluate the relationship between assessed buoyancy and body composition. Twenty-seven women (age: 20 ± 3 years, height: 1.66 ± 0.34 m, weight: 62 ± 7 kg; body mass index: 22 ± 2; vital capacity: 4.26 ± 0.47 l) and twenty-six men (age: 19 ± 2 years, height: 1.81 ± 6.76 m, weight: 79 ± 10 kg body mass index: 24 ± 3; vital capacity: 6.05 ± 0.7 l) volunteered to participate in the study. They performed floating tests, underwater weighing, pulmonary function measurement, and body composition procedure on the same day in random order with a 30-minute break. Floating testing consisted of one horizontal (HT) and two vertical tests with different arm positions, i.e., arms adducted to the body (VT1) or arms extended overhead (VT2). We assessed participants' buoyancy (B-HT, B-VT1, and B-VT2). In addition, we calculated participants' body volume and buoyancy (B-c) using variables measured during underwater weighing. Results showed that B-c was moderately correlated with B-VT1 (Spearman's ρ = 0.51; p < 0.001) and B-VT2 (Spearman's ρ = 0.55; p < 0.001), but not with B-HT. Multiple regression analysis showed that vital capacity and muscle mass had a positive and negative effect, respectively, on the scores of buoyancy assessed by vertical floating tests. In addition, the mass of the arms correlated negatively with the scores of buoyancy assessed by VT2 (β = -6.26; p = 0.005). According to the obtained results, we can conclude that both vertical floating tests i.e. with arms adducted to the body or arms extended overhead are suitable substitutes for underwater weighing to determine buoyancy, which is strongly related to vital capacity and lesser extent to muscle mass. Muscle mass is not a factor that can be changed immediately, while the amount of inspiration can be regulated. Therefore, the control of breathing and thus the reduction or increase of buoyancy is an important skill that novice swimmers should acquire as part of the learn-to-swim program.

A More Comfortable Method for Hydrostatic Weighing: Head above Water at Total Lung Capacity.

Hydrostatic weighing (HW) requires full submersion with the lungs at residual volume (RV) which is uncomfortable. Therefore, the purpose of this study was to find a more comfortable way to complete HW. A HW system was used to complete three comparisons: comparison 1: change in head position (head above water vs. head below water (HAW vs. HBW)), comparison 2: change in lung volume (total lung capacity (TLC) vs. RV), and comparison 3: change in head and lung volume changes. Participants were separated by males (n = 64) and females (n = 58). Comparison 1: HAW resulted in higher mean percent body fat (PBF) than HBW (4.5% overall, 3.8% in males, 5.4% in females, p < 0.05). Comparison 2: TLC resulted in lower mean PBF than RV (5.1% overall, 5.3% in males, 4.8% in females, p < 0.05). Comparison 3: HAW@TLC resulted in significantly lower (1.5% lower, p = 0.003) mean PBF for males but was not significantly lower for females or overall (0.6% higher, p = 0.39, 0.6% lower, p = 0.18, respectively) compared to HBW@RV. In conclusion, keeping the head above water and taking a deep inhale makes HW a more enjoyable, and accessible experience for everyone while still producing accurate PBF results.

Accuracy and precision of multiple body composition methods and associations with muscle strength in athletes of varying hydration: The Da Kine Study

BackgroundAthletes vary in hydration status due to ongoing training regimes, diet demands, and extreme exertion. With water being one of the largest body composition compartments, its variation can cause misinterpretation of body composition assessments meant to monitor strength and training progress. In this study, we asked what accessible body composition approach could best quantify body composition in athletes with a variety of hydration levels. MethodsThe Da Kine Study recruited collegiate and intramural athletes to undergo a variety of body composition assessments including air-displacement plethysmography (ADP), deuterium-oxide dilution (D2O), dual-energy X-ray absorptiometry (DXA), underwater-weighing (UWW), 3D-optical (3DO) imaging, and bioelectrical impedance (BIA). Each of these methods generated 2- or 3-compartment body composition estimates of fat mass (FM) and fat-free mass (FFM) and was compared to equivalent measures of the criterion 6-compartment model (6CM) that accounts for variance in hydration. Body composition by each method was used to predict abdominal and thigh strength, assessed by isokinetic/isometric dynamometry. ResultsIn total, 70 (35 female) athletes with a mean age of 21.8 ± 4.2 years were recruited. Percent hydration (Body Water6CM/FFM6CM) had substantial variation in both males (63- 73%) and females (58- 78%). ADP and DXA FM and FF M had moderate to substantial agreement with the 6C model (Lin’s Concordance Coefficient [CCC] = 0.90-0.95) whereas the other measures had lesser agreement (CCC < 0.90) with one exception of 3DO FFM in females (CCC = 0.91). All measures of FFM produced excellent precision with %CV < 1.0 %. However, FM measures in general had worse precision (% CV < 2.0%). Increasing quartiles (significant p<0.001 trend) of 6CM FFM resulted in increasing strength measures in males and females. Moreover, the stronger the agreement between the alternative methods to the 6CM, the more robust their correlation with strength, irrespective of hydration status. ConclusionThe criterion 6CM showed the best association to strength regardless of the hydration status of the athletes for both males and females. Simpler methods showed high precision for both FM and FFM and those with the strongest agreement to the 6CM had the highest strength associations. Summary BoxThis study compared various body composition analysis methods in 70 athletes with varying states of hydration to the criterion 6-compartment model and assessed their relationship to muscle strength. The results showed that accurate and precise estimates of body composition can be determined in athletes, and a more accurate body composition measurement produces better strength estimates. The best laboratory-based techniques were air displacement plethysmography and dual-energy x-ray absorptiometry, while the commercial methods had moderate-poor agreement. Prioritizing accurate body composition assessment ensures better strength estimates in athletes.

EFFECTS OF INTERMITTENT FASTING IN BODY COMPOSITION ON OBESE PEOPLE: A SYSTEMATIC REVIEW

This article has been developed to address the impact of intermittent fasting on the body composition of obese individuals. Presently there are about 650 million obesity-affected individuals worldwide. Intermittent fasting is primarily implemented and practised to contribute to better health conditions and weight loss. The prevalence is measured by a BMI above 25, identified as overweight and BMI above 30, identified as obese. This paper has a systematic literature review of relevant studies to develop understanding and idea development. Data extraction for this article has followed the PRISMA model extracting 25 relevant journals from 55 initial considerations. The findings have been represented following a thematic approach addressing the effects, strategies and challenges of intermittent fasting. The Twice-a-week Method, Alternate Day Fasting, Time Restricted Eating and the 24 Hour Fast respective intermittent fasting techniques have been evaluated. Calorie intake restrictions and fasting are fundamental contributing factors to developing hypoglycemia or “type 2 diabetes”, which is identified as an impact of intermittent fasting. Recommendations have been farmed addressing better practice and inclusion of intermittent fasting by Controlled Practice of Intermittent Fasting and Compliance with Medical Conditions. KEYWORDS: Intermittent Fasting, Underwater Weighing, obesity, overweight, weight loss, body, composition

Agreement and Validity of Existing Anthropometric Calibration Models to Estimate Whole Body Density in Male Professional Football Players

Introduction To date no calibration models exist to estimate whole body density (Db) of professional footballers, as such the development of practical anthropometric calibration models to make sound body composition judgements is imperative. The aim of this study was to investigate the agreement and validity of estimating Db from 15 existing calibration models through comparison to a criterion method of hydrostatic weighing (HW) in male professional footballers. Materials and Methods Data were gathered from a total of n=206 professional football participants (x±s; age=24.1±5.4-years, body mass=78.8±8.4 kg, stature=180.1±7.0 cm, Db 1.075±0.01 g.ml-1). Bland and Altman limits of agreement (LoA) approaches were used to determine bias and random variation derived from the calibration models. Results Bias and random errors for the published calibration models ranged from -0.005 to +0.015 g.ml-1 and 1.012 to 1.090 g.ml-1 respectively. A priori criterion (±3.8% p=&lt;0.05 (g.ml-1)) was set as acceptable limits for the LoA method of which 13 calibration models found that (on average) estimated Db derived from HW was greater than Db derived from the models. Discussion A rank order of LoA identified the best model to use, however, LoA were not narrow enough for measurements to be of practical use and in most instances, selected models are not appropriate for estimating Db in male professional footballers.

New Equations for Hydrostatic Weighing without Head Submersion.

New equations were derived to predict the density of the body (DB) by hydrostatic weighing with the head above water (HWHAW). Hydrostatic weighing with the head below water (HWHBW) was the criterion for DB measurement in 90 subjects (44 M, 46 F). Head volume by immersion (HVIMM) was determined by subtracting the mass in water with the head below water (MWHBW) from the mass in water with the head above water (MWHAW), with subjects at residual lung volume. Equations were derived for head volume prediction (HVPRED) from head measurements and used to correct DB by HWHAW. Equations were also derived for HWHAW using direct regression of DB from uncorrected density (with MWHAW in place of MWHBW). Prediction equations were validated in 45 additional subjects (21 M, 24 F). Results were evaluated using equivalence testing, linear regression, Bland–Altman plots, and paired t-tests. Head girth, face girth, and body mass produced the smallest errors for HVPRED. In both M and F validation groups, equivalence (±2% fat by weight) was demonstrated between body fat percent (BF%) by HWHBW and BF% by HWHAW with HVPRED. Variance in computer-averaged samples of MWHAW was significantly less (p < 0.05) than MWHBW. Prediction error was smaller for BF% by HWHAW with HVPRED than for alternative methods. Conclusions: Equivalence between BF% by HWHBW and BF% by HWHAW with HVPRED was demonstrated and differences were not statistically significant. Weight fluctuations were smaller for HWHAW than HWHBW.

Body Composition Assessment in Masters Level Swimmers

Body composition of collegiate swimmers has been extensively studied; however, there are limited reports of body composition among Masters swimmers. This study compared the accuracy of air displacement plethysmography (ADP) and bioelectrical impedance (BIA) to the gold standard method of underwater weighing (UWW) in Masters level swimmers. The relationship between percent body fat (%BF) and body mass index (BMI) was also assessed. Recruitment (n = 6 females, 11 males) occurred at two Masters swim clubs. Pearson correlation coefficients revealed no significant differences between ADP, BIA, and UWW (p &gt; 0.05). For both female and male Masters swimmers, the mean %BF was in the healthy range (30.4 ± 11.7% female, 21.3 ± 8.0% male); however, BMI was in the overweight range (27.0 ± 7.2 kg/m2 female, 26.4 ± 4.8 kg/m2 male). These findings suggest that while ADP, BIA, and UWW were comparable methods for assessing %BF in Masters swimmers, BMI did not adequately represent body composition and health risk for Masters swimmers.

Measurement of Body Composition in the Dehydrated State

The purpose of the study is to examine the effect of exercise-induced dehydration on body composition using three indirect methods: bioelectrical impedance analysis (BIA), skinfold thickness (SF), and underwater weighing (UWW).Method: Thirty healthy, physically active subjects with normal weight (22 males) participated as study subjects. After baseline body composition measurements using the above three methods were obtained, the subjects began to dehydrate by exercise until an average of 1.5% body weight loss was accomplished. Within 10 minutes post-exercise, the subjects’ body composition measurements using the same measurement methods were repeated. Results: There was a significant (p&lt;0.05) difference between the three methods for determining fat free mass (FFM), fat mass (FM), and percent body fat (%BF). The %BF and FM measurements using the BIA method were significantly (p&lt;0.05) affected by exercise-induced dehydration, but not the UWW or the SF method. Compared to the UWW method before dehydration, the SF method significantly (p&lt;0.05) under-estimated FM, %BF, and over-estimated FFM, whereas the BIA method significantly (p&lt;0.05) over-estimated FM and % BF, and under-estimated FFM. These observations also occur after exercise-induced dehydration. Comparing genders, the BIA method produced higher %BF and FM values in the female subjects than in the male subjects both before and after dehydration. Conclusion: We concluded that exercise-induced dehydration of 1.5% weight loss significantly (p&lt;0.05) limits the usefulness of the BIA method for determining human body composition in physically active and normal weight adults, whereas dehydration induced an insignificant effect on the SF or UWW method.

New apparatus for the determination of liquid density at primary level in TUBITAK UME

This work aimed to describe the new apparatus of TUBITAK UME for determining the density of liquids at the primary level by means of a hydrostatic weighing (HW) using a solid density standard. This new apparatus provides TUBITAK UME with the necessary infrastructure to certify reference liquids of density with adequate uncertainty to be used at a secondary level, such as for calibration of oscillation type density meters. The HWS produces reference values for liquids with different physical properties such as viscosity, surface tension and viscoelasticity in the case of non-Newtonian liquids. In this HWS, the automation of all mechanical parts such as loading/unloading of the reference weights and sinker, movement of bath, working of pump etc. took place. In this way, the primary level liquid density measurements were realized with uncertainities smaller than 0,01 kg/m3. The automation also effected the robustness of the system by providing the lower repeatability value and stabilization of temperature.

Validity of a 3-compartment body composition model using body volume derived from a novel 2-dimensional image analysis program.

The purpose of this study was: (1) to compare body volume (BV) estimated from a 2-dimensional (2D) image analysis program (BVIMAGE), and a dual-energy x-ray absorptiometry (DXA) equation (BVDXA-Smith-Ryan) to an underwater weighing (UWW) criterion (BVUWW); (2) to compare relative adiposity (%Fat) derived from a 3-compartment (3C) model using BVIMAGE (%Fat3C-IMAGE), and a 4-compartment (4C) model using BVDXA-Smith-Ryan (%Fat4C-DXA-Smith-Ryan) to a 4C criterion model using BVUWW (%Fat4C-UWW). Forty-eight participants were included (60% male, 22.9 ± 5.0 years, 24.2 ± 2.6 kg/m2). BVIMAGE was derived using a single digital image of each participant taken from the rear/posterior view. DXA-derived BV was calculated according to Smith-Ryan et al. Bioimpedance spectroscopy and DXA were used to measure total body water and bone mineral content, respectively, in the 3C and 4C models. A standardized mean effect size (ES) assessed the magnitude of differences between models with values of 0.2, 0.5, and 0.8 for small, moderate, and large differences, respectively. Data are presented as mean ± standard deviation. Near-perfect correlation (r = 0.998, p < 0.001) and no mean differences (p = 0.267) were observed between BVIMAGE (69.6 ± 11.5 L) and BVUWW (69.5 ± 11.4 L). No mean differences were observed between %Fat4C-DXA-Smith-Ryan and the %Fat4C-UWW criterion (p = 0.988). Small mean differences were observed between %Fat3C-IMAGE and %Fat4C-UWW (ES = 0.2, p < 0.001). %Fat3C-IMAGE exhibited smaller SEE and TE, and tighter limits of agreement than %Fat4C-DXA-Smith-Ryan. The 2D image analysis program provided an accurate and non-invasive estimate of BV, and subsequently %Fat within a 3C model in generally healthy, young adults.

Direct Comparison of (Anthropometric) Methods for the Assessment of Body Composition

Objective: Several methods for the assessment of body composition exist, yet they yield different results. The present study aimed to assess the extent of these differences on a sample of young, healthy subjects. We hypothesised that differences in body composition results obtained with different methods will vary to the extent that a subject can be misclassified into different nutritional categories. Research Methods and Procedures: Underwater weighing (UWW), bioelectrical impedance analysis (BIA), anthropometry (ANT), and dual-energy X-ray absorptiometry (DXA) were used to assess body composition. An extensive list of ANT regression equations (or sets of equations) was analysed in terms of accuracy and precision relative to DXA. Results: When DXA-determined body fat (BF) values were taken as a reference, UWW overestimated BF in both genders. In contrast, BIA (measured with a given bioimpedance analyser) underestimated BF in females, although BIA-determined BF did not differ from DXA in males. A huge difference in BF estimates (8–29% for females and 6–29% for males, for DXA-determined BF of 25.5% and 13.9% for females in males, respectively) was observed across a number of ANT regression equations; yet, ANT proved not to be inferior to DXA, provided that regression equations with the highest combinations of accuracy and precision were chosen. Conclusions: The study proved grounds for comparison of body composition results of young, healthy subjects, obtained with different methods and across a wide range of ANT regression equations. It also revealed a list of the most appropriate ANT regression equations for the selected sample and reported their accuracy and precision.

An Equation To Estimate Head Volume For Hydrostatic Weighing In Partially Immersed Subjects

An Equation To Estimate Head Volume For Hydrostatic Weighing In Partially Immersed Subjects

Developing the NIS solid density hydrostatic weighing system up to 20 kg

This paper presents a developed design and construction to improve the performance and increasing the density measuring capability of the previous Hydrostatic Weighing Apparatus (HWA-NIS) at the National Institute of Standards (NIS) up to 20 kg. The previous (HWA-NIS) has been constructed up to 10 kg on 2014. The 2-Positions mass handler in the previous (HWA) was developed with 4-Positions pentagon shape to be able to make handling for individual masses in a group at once, when transferring the traceability from the primary standard “the Silicon Sphere” to the standard masses in the density scale weighing process. The weighing pan in the previous (HWA) was developed with four suspension wires with a diameter of 0.3 mm each, leads to reduce the surface tension affect on the measurement uncertainty by factor four times. The density of the standard masses in the range from 2 kg up to 20 kg were measured with an improved expanded uncertainty from 0.150 kg/m3to 0.078 kg/m3respectively due to reducing the effect of surface tension via the developed design of the weighing pan.

New Multisite Bioelectrical Impedance Device Compared to Hydrostatic Weighing and Skinfold Body Fat Methods

New Multisite Bioelectrical Impedance Device Compared to Hydrostatic Weighing and Skinfold Body Fat Methods

Validity and reliability of a Wi-Fi smart scale to estimate body composition

With patients depending on ‘at-home’ devices to measure or monitor body composition changes to determine health- risks, there is the need for critical evaluation of these instruments. The purpose of this study was to determine the validity (i.e., accuracy) and reliability (i.e., consistency) of body fat percentage (BF%) estimates using the consumer Fitbit Aria™ foot-to-foot bioelectrical impedance analysis (BIA) Wi-Fi smart scale. Forty-three healthy volunteers [male (n = 22), female (n = 21); mean ± SD, age: 27.9 ± 5.6y; BMI: 23.7 ± 3.3 kg/m2] underwent measures of residual lung volume, hydration status, and BF% via the Aria™ smart scale [‘Regular’ (AR) and ‘Lean’ (AL) modes] vs. [hydrostatic weighing (HW)] on three separate days. Aria™ validity was assessed using Bland-Altman plots identifying mean biases and limits of agreement [mean difference (Aria–HW) ± 1.96SD] and between-day and -week reliability using two-way mixed, average measures absolute agreement intraclass correlation coefficients (ICC). Standard error of estimate (SEE) could not exceed ±3.5% for acceptable non-research agreement between methods. There were no significant differences between HW compared with AR for all participants (−0.3 ± 9.7%), females (1.1 ± 11.3%), and males (−1.6 ± 7.1%). AL also agreed with HW for females (−1.9 ± 8.6%), but significantly underestimated BF% for all participants and males when analyzed separately (p ≤ 0.05). However, in each measure of validity the SEE fell outside ±3.5%, suggesting BF% measurements from HW and this smart scale cannot be used interchangeably. While not accurate for all individuals, the Aria™ Wi-Fi smart scale is a reliable device to measure BF% over time. Health care professionals may consider recommending this technology to empower patients who want to monitor their body composition at home.

Comparison of Different Methods Used to Assess Body Composition in College Aged Athletes

With the prevalence of obesity increasing to almost 40% as of 2016 and the vast amount of health complications known to be associated with being overweight or obese, knowing one’s body composition is increasingly important. The American College of Sports Medicine has recommended values for % body fat that places individuals into different categories (from very lean to very poor), based on sex and age. However, these categories of % body fat are based on the use of Skinfold Thickness measurements. There are now numerous ways in which to assess body composition and we don’t know the variability that may exist between these methods. PURPOSE: The purpose of this study was to compare the most common methods of measuring body composition that are currently being used today in order to determine- 1) how much of a difference exists between the different techniques, and 2) the relationship of the different methods of measuring body composition. METHODS: Thirty-nine healthy males (age=20±2 y; body weight=97.38±21.26 kg; height=1.79±0.06m) had their body composition assessed five different ways. Prior to each testing day subjects completed a 10-12 hour fast, did not exercise, and had a Urine Specific Gravity of <1.02. Body composition assessments included skinfold (SF) thickness (Lange Skinfold Caliper), Dual Energy X-Ray Absorptiometry (DXA; GE Advanced Prodigy DXA Encore V17 Software), Ultrasound Thickness (US; BodyMetrix), Bioelectric Impedance (BIA; Tanita Body Composition Analyzer, BF-350), and Underwater Weighing (UWW; Exertech Floatweight System). RESULTS: Body fat % for US was 17.62±6.82%, SF 17.69±7.59%, UWW 21.94±8.97%, BIA, 23.64±7.74%, and DXA 24.98±8.63%. In comparison to DXA, % fat was significantly greater than US, SF, and UWW (p<0.001). In respect to the relationship to DXA, correlations ranged from .873 (DXA vs. BIA p=0.001) to .957 (DXA vs SF p=0.001). CONCLUSIONS: These results suggest that a difference in body fat up to 7.36% can be observed between the different methods assessed. However, the relationship between the different methods is fairly strong. Due to the large variability observed in the different body composition methods assessed, it would suggest the need for developing recommended standard ranges based on the body composition assessment utilized.

Reliability and validity of various laboratory methods of body composition assessment in young adults

Accurate measures of body composition (BC) are essential for performance and health. In addition to accuracy, BC measures should be practical and be minimally invasive to maximize their utility. The purpose of the present study was to compare the day-to-day variability and validity of four common laboratory-based body composition assessments to a criterion four-compartment model. Dual x-ray absorptiometry (DXA), air displacement plethysmography (BP), multi-frequency bioelectrical impedance (MF-BIA) and underwater weighing (UWW) were performed twice in a sample of 32 young men and women. Participants were assessed in a fasted, euhydrated state 2-7days apart. All methods were compared to a criterion four-compartment model using BP-derived body volume, DXA-derived bone mineral content and MF-BIA-derived total body water (4CBP ). Additional four-compartment models using UWW- and DXA-derived body volume were also examined (4CUWW ) and (4CDXA ). Validity results were conducted with paired t-tests and Bland-Altman analysis. Reliability was determined using intraclass correlations (ICC), coefficients of variation (CV) and standard error of the measurement (SEM). Validity analysis revealed that all methods overestimated per cent body fat and fat mass, and underestimated fat-free mass when compared with 4CBP , but only DXA and BP were significantly different (P<0·008). All measures were highly reliable across days (ICCs>0·9, CVs<12%). Results of the present study indicate that typical laboratory-based methods of body composition are valid and reliable. However, we caution that results should not be translated between methods and assessments should be performed with the same instrument when the goal is to monitor changes in body composition over time.

Consideration on the Procedure of Precise Density Measurements for Seawater Using Hydrostatic Weighing Method

Consideration on the Procedure of Precise Density Measurements for Seawater Using Hydrostatic Weighing Method

Impact of Measured vs. Predicted Residual Lung Volume on Body Fat Percentage Using Underwater Weighing and 4-Compartment Model.

Nickerson, BS, Esco, MR, Bishop, PA, Schumacker, RE, Richardson, MT, Fedewa, MV, Wingo, JE, and Welborn, BA. Impact of measured vs. predicted residual lung volume on body fat percentage using underwater weighing and 4-compartment model. J Strength Cond Res 31(9): 2519-2527, 2017-The purpose of this study was to compare underwater weighing (UWW) and 4-compartment (4C) model body fat percentage (BF%) for predicted vs. simultaneously measured residual lung volume (RLV). Forty-seven women and 33 men (age = 22 ± 5 years) had UWW and 4C model BF% determined using Boren et al. (RLVBOREN), Goldman and Becklake (RLVGB), and Miller et al. (RLVMILLER) RLV prediction equations. Criterion UWW BF% included body density (BD) values with simultaneous RLV. Criterion 4C model BF% included BD through UWW with simultaneous RLV, total body water through bioimpedance spectroscopy, and bone mineral content through dual-energy x-ray absorptiometry. The standard error of estimate (SEE) for UWW and 4C model BF% determined through RLV prediction equations varied from 2.0 to 2.6% and from 1.3 to 1.5%, respectively. The constant error (CE) was significantly different for UWW BF% when using RLVBOREN, RLVGB, and RLVMILLER (all p < 0.016; CE = 0.7, -2.0, 1.0%, respectively). However, the CEs for RLVBOREN and RLVMILLER were not significant in the 4C model (p = 0.73 and 0.11; CE = 0.1 and 0.2%, respectively), whereas RLVGB remained significantly different (p < 0.001; CE = -1.5%). The 95% limits of agreement were less than ±5.2% for UWW BF% and less than ±3.1% for the 4C model when using the 3 RLV equations. When used in a 4C model, the RLV equations yielded a smaller CE, SEE, and 95% limits of agreement than UWW BF% results. However, because of the range of individual error shown in the current study, caution should be employed when using the 4C model as a criterion method with predicted RLV.

Acurácia de índices alternativos para avaliar o estado nutricional de homens e mulheres

A good evaluation of the nutritional status requires knowledge on body composition, casting doubts on the accuracy of some indexes. herefore, the aim of this study was to analyze the accuracy of the following nutritional status indexes: Body Mass Index (BMI), BMI elevated to 2.5 (BMI2.5), Fat Mass Index (FMI) and BMI adjusted for fat mass (BMIfat). Participated of this study 280 subjects (aged 17-48 years), from which the results of BMI, BMI2.5, FMI and BMIfat indexes were analyzed, having the Hydrostatic Weighing method as reference. FMI presented the highest concordance value, but classiied as discrete (k=0.21). he other indexes presented small concordance with results of the reference method (k&lt;0.20). In conclusion, none of the indexes investigated has good accuracy in assessing the nutritional status of the study group, considering that, although they show results of correlation with the reference method, they do not reach the minimum agreement criterion.