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Cited by 46Body Composition Measurement TechniquesElectrical and Bioimpedance TomographyIndigenous Health and Education

Body fat measurement by bioelectrical impedance and air displacement plethysmography: a cross-validation study to design bioelectrical impedance equations in Mexican adults

Open access
Macias, Nayeli, Alemán-Mateo, Heliodoro, Esparza-Romero, Julián, Valencia, Mauro E·2007·Nutrition Journal
DOI 10.1186/1475-2891-6-18PMC PMC2020472
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Abstract

Background: The study of body composition in specific populations by techniques such as bio-impedance analysis (BIA) requires validation based on standard reference methods. The aim of this study was to develop and cross-validate a predictive equation for bioelectrical impedance using air displacement plethysmography (ADP) as standard method to measure body composition in Mexican adult men and women. Methods: This study included 155 male and female subjects from northern Mexico, 20–50 years of age, from low, middle, and upper income levels. Body composition was measured by ADP. Body weight (BW, kg) and height (Ht, cm) were obtained by standard anthropometric techniques. Resistance, R (ohms) and reactance, Xc (ohms) were also measured. A random-split method was used to obtain two samples: one was used to derive the equation by the "all possible regressions" procedure and was cross-validated in the other sample to test predicted versus measured values of fat-free mass (FFM). Results and Discussion: The final model was: FFM (kg) = 0.7374 * (Ht 2 /R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658. R 2 was 0.97; the square root of the mean square error (SRMSE) was 1.99 kg, and the pure error (PE) was 2.96. There was no difference between FFM predicted by the new equation (48.57 ± 10.9 kg) and that measured by ADP (48.43 ± 11.3 kg). The new equation did not differ from the line of identity, had a high R 2 and a low SRMSE, and showed no significant bias (0.87 ± 2.84 kg). Conclusion: The new bioelectrical impedance equation based on the two-compartment model (2C) was accurate, precise, and free of bias. This equation can be used to assess body composition and nutritional status in populations similar in anthropometric and physical characteristics to this sample.

AI snapshot

Written from the paper’s full text.

TL;DR

This cross-validation study developed and tested a bioelectrical impedance equation for fat-free mass in Mexican adults using air displacement plethysmography as the reference method. The new equation was reported as accurate, precise, and free of bias in the validation sample.

Key findings

  • The final BIA equation was: FFM (kg) = 0.7374 × (Ht²/R) + 0.1763 × (BW) − 0.1773 × (Age) + 0.1198 × (Xc) − 2.4658, with R² = 0.97, SRMSE = 1.99 kg, and pure error = 2.96.
  • In the validation sample, predicted FFM was 48.57 ± 10.9 kg versus ADP-measured FFM 48.43 ± 11.3 kg, with no significant difference; regression showed intercept 0.02, slope 0.98, R² = 0.92, and SRMSE = 2.86.
  • Bland-Altman analysis found a bias of −0.87 ± 2.84 kg FFM, with limits of agreement from −6.56 to +4.82 kg, and no significant association between mean differences and mean measurements.
  • Body fat estimates by ADP versus BIA were similar: males 25.9 ± 6.9% vs 25.8 ± 5.9%, and females 36.2 ± 6.5% vs 36.1 ± 6.1%.

Methods

  • Cross-sectional study of 155 healthy adults (82 women, 73 men), aged 20–50 years, from Sonora, Mexico, selected by nonprobabilistic sampling between 2000 and 2001; pregnant/lactating women and those with conditions or medications affecting body composition were excluded.
  • Body composition was measured by ADP (Bod Pod), with anthropometry and BIA resistance/reactance also measured; ADP reproducibility was tested in duplicate measurements from 91 subjects.
  • The sample was randomly split into an equation sample (n = 78) and validation sample (n = 77); the equation was derived using “all possible regressions” with Mallows’ Cp, then cross-validated with paired t-tests, regression, and Bland-Altman analysis.

Limitations

  • Stated: the authors acknowledge a possible problem of generality because the sample does not include Mexicans from all regions of the country, and ethnic/environmental differences could affect general applicability, so the equation should be used with caution.
  • Evident: the study used a single-center, nonprobabilistic, cross-sectional sample of healthy 20–50-year-olds from Sonora, so findings may not extend to other age groups, regions, or clinical populations.
  • Evident: no external validation is reported; the authors also note that more validation studies using a 4-compartment model as the gold standard are required, although they cite prior local ADP validation in elderly subjects and ongoing studies in children/adolescents.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1186/1475-2891-6-18

Cites

35 of 35 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

5 of 27 cited sources checked · 4 supported · 0 flagged · accuracy not yet measured

  • Premisecitation

    ADP is a valid method to determine body composition compared with hydrodensitometry and the four-compartment model in adults.

    “Recently, it has been reported that air displacement plethysmography (ADP) is a valid method to determine body composition compared with hydrodensitometry and the four compartment model in adults [5,6].”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites [5] Demerath EW, Guo SS, Chumlea WC, Towne B, Roche AF, Siervogel RM: Comparison of percent body fat estimates using air displacement plethysmography and hydrodensitometry in adults and children. Int J Obes Relat Metab Disord. 2002, 26 (3): 389-397. 10.1038/sj.ijo.0801898. source
    • cites [6] Fields DA, Goran MI, McCrory MA: Body-composition assessment via air-displacement plethysmography in adults and children: a review. Am J Clin Nutr. 2002, 75 (3): 453-467. source
  • Premisecitation

    The body composition variables selected in the final model have been reported as the best predictors in BIA equations designed to estimate FFM.

    “The body composition variables selected in the final model of this study have been reported as the best predictors in BIA equations designed to estimate FFM [25-27].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [25] Guo SS, Chumlea WC, Cockram DB: Use of statistical methods to estimate body composition. Am J Clin Nutr. 1996, 64 (3 Suppl): 428S-435S. source

      The “Published Prediction Equations” passage (page not supplied) says BIA equations commonly used FFM as the outcome and used S²/R and weight most often, followed by stature, sex, and age. It supports the general connection between these variables and FFM prediction, but does not identify the citing study’s final-model variables or establish that they are the best predictors. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
    • cites [26] Baumgartner RN, Heymsfield SB, Lichtman S, Wang J, Pierson RN: Body composition in elderly people: effect of criterion estimates on predictive equations. Am J Clin Nutr. 1991, 53 (6): 1345-1353. source
    • cites [27] Lukaski HC, Bolonchuk WW, Hall CB, Siders WA: Validation of tetrapolar bioelectrical impedance method to assess human body composition. J Appl Physiol. 1986, 60 (4): 1327-1332. source
  • Findingown data

    There were no significant differences between the randomized equation sample and the validation sample in the measured characteristics.

    “There were no significant differences between the values from the randomized sample used for developing the equation and the randomized sample for testing it.”
    Quote in the paperSubstantial claim
  • Findingown data

    There was no significant difference between FFM predicted by the new BIA equation (48.57 ± 10.9 kg) and FFM measured by ADP (48.43 ± 11.3 kg) in the validation sample.

    “There was no difference between FFM predicted by the new equation (48.57 ± 10.9 kg) and that measured by ADP (48.43 ± 11.3 kg).”
    • Also stated in: § Results · plain
      “The mean values of FFM predicted by the new BIA equation and measured by ADP in the validation sample were 48.57 ± 10.9 kg and 48.43 ± 11.3 kg, respectively.”
    Quote in the paperSubstantial claim
  • Findingown data

    The final BIA equation for fat-free mass in Mexican adults is FFM (kg) = 0.7374 * (Ht2/R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658.

    “The final model was: FFM (kg) = 0.7374 * (Ht2 /R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658.”
    • Also stated in: § Results · plain
      “FFM (kg) = 0.7374 * (Ht2/R) + 0.1763 * (BW)- 0.1773 * (Age) + 0.1198 * (Xc)- 2.4658”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 16
  • May combine two claims. 22
  • The quote only partly states this claim. 1

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The best BIA equations developed for specific population groups have been properly validated.

    “The best BIA equations developed for specific population groups have been properly validated [22-24].”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [22] Masuda T, Komiya S: A prediction equation for total body water from bioelectrical impedance in Japanese children. J Physiol Anthropol Appl Human Sci. 2004, 23 (2): 35-39. 10.2114/jpa.23.35. source
    • cites [23] Kyle UG, Genton L, Karsegard L, Slosman DO, Pichard C: Single prediction equation for bioelectrical impedance analysis in adults aged 20--94 years. Nutrition. 2001, 17 (3): 248-253. 10.1016/S0899-9007(00)00553-0. source
    • cites [24] Valencia ME, Aleman-Mateo H, Salazar G, Hernandez Triana M: Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico. Int J Obes Relat Metab Disord. 2003, 27 (7): 848-855. 10.1038/sj.ijo.0802315. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    A review of ADP versus hydrostatic weighing in adults found mean group differences from -4% to 1.9% body fat, with 5 of 12 studies showing no significant difference, inconsistent direction among the other 7, and percent fat by ADP explaining 78-94% of the variance in percent body fat by HW with SEEs of 1.8 to 2.3%.

    “Mean group differences between ADP and HW measurements ranged from -4% to 1.9 % body fat; 5 of the 12 studies showed no significant difference between the two methods. Of the other 7 studies that did show a significant mean difference, the direction of the differences was inconsistent. Percent fat measured by ADP explained 78–94 % of the variance in % body fat measured by HW and the reported SEEs”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [6] Fields DA, Goran MI, McCrory MA: Body-composition assessment via air-displacement plethysmography in adults and children: a review. Am J Clin Nutr. 2002, 75 (3): 453-467. source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    It is impossible to separate the confounding effects of subject sex and percent body fat in ADP versus hydrostatic weighing studies.

    “Therefore they conclude that in their analysis as in the individual studies, it is impossible to separate the confounding effects of subject sex and % body fat.”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [6] Fields DA, Goran MI, McCrory MA: Body-composition assessment via air-displacement plethysmography in adults and children: a review. Am J Clin Nutr. 2002, 75 (3): 453-467. source

  • May combine two claims.

    Findingown data

    Bland-Altman analysis showed a bias of -0.87 ± 2.84 kg FFM, with limits of agreement from -6.56 to +4.82 kg FFM.

    “Bland and Altman analysis revealed that the bias expressed as the mean of the difference in FFM measured by ADP and that estimated from the new BIA equation was -0.87 ± 2.84 kg of FFM. The limits of agreement, defined as mean ± 2 SDs, were from -6.56 to + 4.82 kg of FFM (Figure 2).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Men had significantly higher values of weight, height, waist, and waist/hip ratio compared with women.

    “As expected, the men had significantly higher values of weight, height, waist, and waist/hip ratio compared with the women.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In this study, percent body fat by the reference method was 25.9 in men and 36.2 in women at BMI values of 25.4 and 26.2, respectively.

    “In our study, the BF% by the reference method was 25.9 in men and 36.2 in women at BMI values of 25.4 and 26.2, respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The validation regression had an R2 of 0.92 and an SRMSE of 2.86.

    “The R2 was 0.92 and the SRMSE was 2.86 (Figure 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The regression of FFM by ADP on FFM by the new BIA equation did not differ from the line of identity: intercept 0.02 not different from zero, slope 0.98 not different from 1.0.

    “There was no significant difference from the line of identity: the intercept was 0.02 and not different from zero, and the slope was 0.98 and not different from 1.0.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Ht2/R and body weight were the best individual predictors of FFM, accounting for 91.5% and 72.7% respectively, whereas reactance accounted for 2.56% and age for 0.38%.

    “By partial R2 analysis, Ht2/R and body weight were the best individual predictors of FFM (kg), and accounted for 91.5% and 72.7% respectively, whereas reactance accounted for 2.56% and age for only 0.38% (Table 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The final BIA model had an R2 of 0.97, an SRMSE of 1.99 kg, and a pure error of 2.96.

    “R2 was 0.97; the square root of the mean square error (SRMSE) was 1.99 kg, and the pure error (PE) was 2.96.”
    • Also stated in: § Results · plain
      “The final model included all these variables, with an F value of 568, R2 of 0.97, an SRMSE of 1.99 kg, and a pure error (PE) of 2.96.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The regression analysis between FFM values estimated with the BIA equation validated in the present study and ADP showed that the BIA equation was accurate and precise.

    “The regression analysis between FFM values estimated with the BIA equation validated in the present study and ADP (Figure 1) showed that the BIA equation was accurate and precise.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Limb length and body weight are positively related to resistance, which is the main predictor of FFM estimated with BIA.

    “The explanation for this could be that limb length and body weight are positively related to resistance, which is the main predictor of FFM estimated with BIA [27].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [27] Lukaski HC, Bolonchuk WW, Hall CB, Siders WA: Validation of tetrapolar bioelectrical impedance method to assess human body composition. J Appl Physiol. 1986, 60 (4): 1327-1332. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Hispanic women have higher adiposity levels than white women, with a higher amount of fat in the trunk and greater abdominal and subscapular thicknesses.

    “They found that Hispanic women have higher adiposity levels than white women. This difference reflected a higher amount of fat in the trunk. Further, abdominal and subscapular thicknesses were greater in Hispanic than in white women.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Casas YG, Schiller BC, DeSouza CA, Seals DR: Total and regional body composition across age in healthy Hispanic and white women of similar socioeconomic status. Am J Clin Nutr. 2001, 73 (1): 13-18. source

  • May combine two claims.

    Premisecitation

    FFM and FM values obtained with equations developed for specific populations are more accurate and precise, as seen in the present study.

    “FFM, and therefore FM, values obtained with equations developed for specific populations are more accurate and precise [8], as seen in the present study.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [8] Rising R, Swinburn B, Larson K, Ravussin E: Body composition in Pima Indians: validation of bioelectrical resistance. Am J Clin Nutr. 1991, 53 (3): 594-598. source

  • May combine two claims.

    Interpretationown data

    The new BIA equation based on the two-compartment model was accurate, precise, and free of bias.

    “The new bioelectrical impedance equation based on the two-compartment model (2C) was accurate, precise, and free of bias.”
    • Also stated in: § Conclusion · plain
      “The new bioelectrical impedance equation based on a two-component model method was accurate, precise, and free of bias.”
    • Also stated in: § Discussion · plain
      “We found the new equation to be accurate, precise, and free of bias.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Study design and conductown data

    ADP reproducibility was tested in 91 subjects; duplicate mean body density measurements were 1.0292 ± 0.019 and 1.0296 ± 0.019, mean difference 0.00007, coefficient of variation 1.89%, and technical error 0.066% fat units.

    “In terms of %BF, the technical error of measurement was 0.066 % fat units, assessed as (Σd2/2n)1/2, where d is the difference between repeated measurements and n is the number of paired repeated measurements.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    The BIA equation developed in this study (R2 = 0.97; SRMSE = 1.99) was similar to or better than the Lukasky equation (R2 = 0.96; SEE = 3.06) and the Baumgartner equation (R2 = 0.91; SEE = 2.47).

    “The BIA equation developed in this study (R2 = 0.97; SRMSE= 1.99) was similar to or better than those obtained with other equations designed with comparable sample sizes, such as that of Lukasky (84 males; 67 females) [27] based on hydrodensitometry (R2 = 0.96; SEE = 3.06), or of Baumgartner (35 males; 63 females)[28] based on a four compartment model (R2 = 0.91; SEE = 2.47).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [27] Lukaski HC, Bolonchuk WW, Hall CB, Siders WA: Validation of tetrapolar bioelectrical impedance method to assess human body composition. J Appl Physiol. 1986, 60 (4): 1327-1332. source
    • cites [28] Baumgartner RN, Chumlea WC, Roche AF: Estimation of body composition from bioelectric impedance of body segments. Am J Clin Nutr. 1989, 50 (2): 221-226. source

  • May combine two claims.

    Study design and conductown data

    No multicollinearity was detected in the final model; the variance inflation factor was 7.7 and the condition number was 9.82.

    “No multicolinearity was detected according to the regression diagnostic; the variance inflation factor (VIF) was 7.7 and the condition number (CN) was 9.82.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data

    These results are those expected for an equation that is population specific.

    “These results are those expected for an equation that is population specific.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Anthropometry was performed by a standardized technician according to Lohman's recommendations.

    “Anthropometry was performed by a standardized technician according to Lohman's recommendations [13].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13] Lohman TG, Roche AF, R M: Anthropometric standardization reference manual. 1988, Champaign, IL , Human Kinetics , 177-

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Deurenberg et al. demonstrated that limb length, expressed as leg length/height, influences body composition values obtained with BIA, and the authors consider the bias between TBW obtained with deuterium dilution and BIA values to be due to ethnic differences.

    “Deurenberg et al. demonstrated that limb length, expressed as leg length/height, influences the body composition values obtained with BIA; the length of the limbs was different among Chinese, Malays, and Indians. The authors consider the bias between TBW obtained with the deuterium dilution method and BIA values to be due to ethnic differences [30].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [30] Deurenberg P, Deurenberg-Yap M, Schouten FJ: Validity of total and segmental impedance measurements for prediction of body composition across ethnic population groups. Eur J Clin Nutr. 2002, 56 (3): 214-220. 10.1038/sj.ejcn.1601303. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    BIA equipment calibration was periodically performed with an electrical resistor, and calibration values were considered normal if they were not higher than 498 ± 2 ohms.

    “BIA equipment calibration was periodically performed with an electrical resistor. Calibration values were considered normal if they were not higher than 498 ± 2 ohms (Ω).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Among Chinese, Malay and Indian subjects, the Chinese showed the lowest body-fat value and Indians the highest at the same BMI level.

    “Among Chinese, Malay and Indian subjects, the Chinese showed the lowest body-fat value and Indians the highest at the same BMI level [17].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [17] Deurenberg-Yap M, Schmidt G, van Staveren WA, Deurenberg P: The paradox of low body mass index and high body fat percentage among Chinese, Malays and Indians in Singapore. Int J Obes Relat Metab Disord. 2000, 24 (8): 1011-1017. 10.1038/sj.ijo.0801353. source

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationcitation

    These findings support the need to develop validated BIA and anthropometric equations for Hispanics.

    “These findings support the need to develop validated BIA and anthropometric equations for Hispanics.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Ethnic and environmental differences are the main factors that could affect the general applicability of the equation, and it should be used with caution.

    “Ethnic and environmental differences are the main factors that could affect the general applicability of the equation, and it should be used with caution.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    All BIA measurements were performed according to Lukasky.

    “All measurements were performed according to Lukasky [14].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] Lukaski HC, Johnson PE, Bolonchuk WW, Lykken GI: Assessment of fat-free mass using bioelectrical impedance measurements of the human body. Am J Clin Nutr. 1985, 41 (4): 810-817. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Other studies suggest it is important to test ADP accuracy in more heterogeneous samples, or in individuals outside the average percent fat range, specifically lean individuals, and to look at possible gender bias.

    “Other studies [31] suggest that that it is important to test its accuracy in more heterogeneous samples, or in individuals outside the average % fat range, specifically lean individuals, and insist in looking at possible gender bias.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] Vescovi JD, Zimmerman SL, Miller WC, Hildebrandt L, Hammer RL, Fernhall B: Evaluation of the BOD POD for estimating percentage body fat in a heterogeneous group of adult humans. Eur J Appl Physiol. 2001, 85 (3-4): 326-332. 10.1007/s004210100459. source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In the authors' laboratory, ADP has previously been validated using a four-compartment model in elderly subjects, as well as in children and adolescents in studies in progress.

    “In our laboratory we have previously validated ADP using a 4 Compartment model in elderly subjects [32] as well as in children and adolescents (studies in progress).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [32] Aleman-Mateo H, Huerta RH, Esparza-Romero J, Mendez RO, Urquidez R, Valencia ME: Body composition by the four-compartment model: validity of the BOD POD for assessing body fat in mexican elderly. Eur J Clin Nutr. 2007

      Not checked in the free run.

28 of 28

  • The paper relies on this without support.

    There are no published BIA equations for Mexican adults.

    “Finally, it is important to mention that most published BIA equations derive from Caucasian populations, and presently there are no published equations for Mexican adults.”

  • The paper relies on this without support.

    Limb length and body weight are strongly related to ethnicity and environmental factors.

    “Limb length and body weight are strongly related to ethnicity and environmental factors.”
2 of 2

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Reported validation bias disagrees with the validation means

    Major

    For the same validation sample, mean ADP FFM minus mean predicted FFM is 48.43 − 48.57 = −0.14 kg, not the reported −0.87 kg bias. The mean of paired differences must equal the difference of the paired means.

    Reported -0.87 · recomputed -0.14

  • Discussion reverses men's and women's BMI values

    Minor

    The discussion assigns BMI 25.4 to men and 26.2 to women, whereas Table 1 assigns those values to women and men, respectively.

2 of 2

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Related

Authors
Macias, N., Alemán-Mateo, H., Esparza-Romero, J., & Valencia, M. E.
Affiliations
Centro de Investigación en Alimentación y Desarrollo (MX)
Corresponding author
Valencia, Mauro E
ORCID
Venue
Nutrition Journal
Publisher
Springer Science and Business Media LLC
Published
2007-08-15
Volume
6
Issue
1
Pages
18-18
ISSN
1475-2891 (ISSN-L)
DOI
10.1186/1475-2891-6-18
PMC
PMC2020472
OpenAlex
W1982805713
Cited by
46
References
35
Citations by year
2026: 6 · 2025: 5 · 2024: 1 · 2023: 2 · 2022: 3 · 2021: 3 · 2020: 1 · 2019: 5 · 2018: 2 · 2017: 1 · 2016: 2 · 2015: 1 · 2014: 3 · 2012: 3
FWCI
0.79
Type
journal article
Language
en
Open access
Licence
Locations
  • Nutrition Journal (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Topics
  • Health Sciences › Medicine › Physiology › Body Composition Measurement Techniques
  • Physical Sciences › Engineering › Electrical and Electronic Engineering › Electrical and Bioimpedance Tomography
  • Health Sciences › Health Professions › General Health Professions › Indigenous Health and Education
Keywords
bioelectrical impedance analysis, air displacement plethysmography, body composition, fat-free mass, cross-validation, Mexican adults, two-compartment model, body fat measurement
MeSH terms
Adipose Tissue, Adult, Anthropometry, Body Composition, Body Height

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