Population Study Article | Published:

Ponderal index classifies obesity in children and adolescents more accurately than body mass index z-scores



We aimed to compare the accuracy of the ponderal index (PI) vs. BMI-for-age z-scores transformed (BMIz) in estimating body fat levels and classifying obesity in children and adolescents from a Brazilian urban population.


This is a cross-sectional study with 1149 participants (53.2% male), aged 6 to 18 years. Body fat percent (BFP) was obtained by multi-frequency bioelectrical impedance. Non-linear regression analysis provided the accuracy of both BMIz and PI in estimating BFP. False positive rate was obtained from the proportion of individuals placed at or above the 95th percentile for BMIz or PI, whereas their BFP was discordantly below the 95th percentile.


PI and BMIz appeared with similar stability from childhood to adolescence for both boys and girls. The portion of the variability in BFP explained by BMIz (R2 = 0.74 and R2 = 0.75) was close to the variability in BFP explained by PI (R2 = 0.73 and R2 = 0.75) for boys and girls, respectively. False positive rate was higher for BMIz compared with PI among boys (21.8% vs. 3.9%) and girls (28.5% vs. 17.5%).


PI is a promising index for replacing BMIz in children and adolescents due to its potential to reduce false diagnosis of obesity.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


  1. 1.

    Lobstein, T., Baur, L. & Uauy, R. IASO International Obesity Task Force. Obesity in children and young people: a crisis in public health. Obes. Rev. 5, 4–104 (2004).

  2. 2.

    Olshansky, S. J. et al. A potential decline in life expectancy in the United States in the 21st century. N. Engl. J. Med. 352, 1138–1145 (2005).

  3. 3.

    Wang, Y., Beydoun, M. A., Liang, L., Caballero, B. & Kumanyika, S. K. Will all Americans become overweight or obese? Estimating the progression and cost of the US obesity epidemic. Obesity. (Silver Spring) 16, 2323–2330 (2008).

  4. 4.

    Ng, M. et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 384, 766–781 (2014).

  5. 5.

    Lobstein, T. et al. Child and adolescent obesity: part of a bigger picture. Lancet 385, 2510–2520 (2015).

  6. 6.

    World Health Organization. Consideration of the evidence on childhood obesity for the Commission on Ending Childhood Obesity: report of the ad hoc working group on science and evidence for ending childhood obesity. (WHO, Geneva, 2016). (http://apps.who.int/iris/bitstream/10665/206549/1/9789241565332_eng.pdf?ua=1).

  7. 7.

    NCD Risk Factor Collaboration. Worldwide trends in body mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128.9 million children, adolescents, and adults. Lancet 390, 2627–2642 (2017).

  8. 8.

    World Health Organization. Obesity and overweight. (WHO, Geneva, Switzerland, 2018). (http://www.who.int/mediacentre/factsheets/fs311/en/).

  9. 9.

    World Health Organization. Report of the Commission on Ending Childhood Obesity: implementation plan: executive summary. (WHO, Geneva, 2017). http://www.who.int/iris/handle/10665/259349.

  10. 10.

    Wang, Y. C., McPherson, K., Marsh, T., Gortmaker, S. L. & Brown, M. Health and economic burden of the projected obesity trends in the USA and the UK. Lancet 378, 815–825 (2011).

  11. 11.

    Reilly, J. J. & Kelly, J. Long-term impact of overweight and obesity in childhood and adolescence on morbidity and premature mortality in adulthood: systematic review. Int J. Obes. 35, 891–898 (2011).

  12. 12.

    Litwin, S. E. Childhood obesity and adulthood cardiovascular disease: quantifying the lifetime cumulative burden of cardiovascular risk factors. J. Am. Coll. Cardiol. 64, 1588–1590 (2014).

  13. 13.

    Twig, G. et al. Body-mass index in 2.3 million adolescents and cardiovascular death in adulthood. N. Engl. J. Med. 374, 2430–2440 (2016).

  14. 14.

    Bibbins-Domingo, K., Coxson, P., Pletcher, M. J., Lightwood, J. & Goldman, L. Adolescent overweight and future adult coronary heart disease. N. Engl. J. Med. 357, 2371–2379 (2007).

  15. 15.

    World Health Organization. Multicentre Growth Reference Study Group. Child Growth Standards: length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age: methods and development. (WHO, Geneva, 2006).

  16. 16.

    Medeiros da Silva Mazzeti, C., Cumpian Silva, J., Rinaldi, A. E. M. & Conde, W. L. The allometric scaling of body mass and height in children and adolescents in five countries. Am. J. Hum. Biol. 30, e23101 (2018).

  17. 17.

    Freedman, D. S. et al. BMI z-scores are a poor indicator of adiposity among 2- to 19-year-olds with very high BMIs, NHANES 1999-2000 to 2013-14. Obesity (Silver Spring) 25, 739–746 (2017).

  18. 18.

    Miller, H. C. & Hassanein, K. Diagnosis of impaired fetal growth in newborn infants. Pediatrics 48, 511–522 (1971).

  19. 19.

    Peterson, C. M. et al. Tri-ponderal mass index vs body mass index in estimating body fat during adolescence. JAMA Pediatr. 171, 629–636 (2017).

  20. 20.

    Lohman T., Roche A., Martorell E. Anthropometric standardization reference manual. (Human Kinetics, Champaign, 1988).

  21. 21.

    Lee, K., Lee, S., Kim, S. Y., Kim, S. J. & Kim, Y. J. Percent body fat cutoff values for classifying overweight and obesity recommended by the International Obesity Task Force (IOTF) in Korean children. Asia Pac. J. Clin. Nutr. 16, 649–655 (2007).

  22. 22.

    McCarthy, H. D., Cole, T. J., Fry, T., Jebb, S. A. & Prentice, A. M. Body fat reference curves for children. Int. J. Obes. 30, 598–602 (2006).

  23. 23.

    Cole, T. J., Bellizzi, M. C., Flegal, K. M. & Dietz, W. H. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ 320, 1240–1243 (2000).

  24. 24.

    Garn, S. M. & Haskell, J. A. Fat thickness and developmental status in childhood and adolescence. AMA J. Dis. Child 99, 746–751 (1960).

  25. 25.

    Garn, S. M., Clark, D. C. & Guire, K. E. Levels of fatness and size attainment. Am. J. Phys. Anthr. 40, 447–449 (1974).

  26. 26.

    Garn, S. M. Obesity in black and white mothers and daughters. Am. J. Public Health 84, 1727–1728 (1994).

  27. 27.

    Katzmarzyk, P. T. et al. Association between body mass index and body fat in 9-11-year-old children from countries spanning a range of human development. Int J. Obes. Suppl. 5, S43–S46 (2015).

  28. 28.

    Burton, R. F. Why is the body mass index calculated as mass/height2, not as mass/height3? Ann. Hum. Biol. 34, 656–663 (2007).

  29. 29.

    Benn, R. T. Some mathematical properties of weight-for-height indices used as measures of adiposity. Brit J. Prev. Soc. Med 25, 42–50 (1971).

  30. 30.

    Wells, J. C. K. & Cole, T. J. and ALSPAC study team. Adjustment of fat-free mass and fat mass for height in children aged 8 y. Int. J. Obes. 26, 947–952 (2002).

  31. 31.

    Jiang, Y. et al. Waist-to-height ratio remains an accurate and practical way of identifying cardiometabolic risks in children and adolescents. Acta Paediatr. 107, 1629–1634 (2018).

  32. 32.

    Ramírez-Vélez, R. et al. Tri-ponderal mass index vs. fat mass/height3 as a screening tool for metabolic syndrome prediction in Colombian children and young people. Nutrients 10, 412 (2018).

  33. 33.

    Margolis-Gil, M., Yackobovitz-Gavan, M., Phillip, M. & Shalitin, S. Which predictors differentiate between obese children and adolescents with cardiometabolic complications and those with metabolically healthy obesity? Pedia. Diabetes 19, 1147–1155 (2018).

  34. 34.

    Lim, J. S. et al. Cross-calibration of multi-frequency bioelectrical impedance analysis with eight-point tactile electrodes and dual-energy X-ray absorptiometry for assessment of body composition in healthy children aged 6–18 years. Pedia. Int. 51, 263–268 (2009).

Download references


The authors wish to thank the unwavering support of Estação Conhecimento” and VALE Foundation, Vitória, ES, Brazil, during the period of data collection. This work was supported by the Pro-Rectory of Research and Post-Graduate Studies of the Federal University of Espírito Santo (Institutional Program Fund for Research Support, 2015); Foundation for Supporting Research and Innovation of Espírito Santo (FAPES)—Research Program for SUS (PPSUS) (grant 65854420/2014); Fundação VALE; and Laboratory Thommasi of Vitória, ES, Brazil, that funded the accomplishment of part of the biochemical exams. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication

Author information

D.Z., P.R.O., and F.S.N. analyzed the data, interpreted the results, and drafted the manuscript. R.d.O.A. participated in the design of the work and contributed to the analysis of data and interpretation of results. V.O.P., C.R.M., and M.A.S.P. contributed to acquisition of data. M.C.R.B. and E.R.d.F. participated in the design of the work and supervised the acquisition of data. J.G.M. conceptualized and designed the study, and critically reviewed the manuscript for important intellectual content. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

Competing interests

The authors declare no competing interests.

Correspondence to Divanei Zaniqueli.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark
Fig. 1
Fig. 2
Fig. 3