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Cited by 89Obesity, Physical Activity, DietBody Composition Measurement TechniquesObesity and Health Practices

The Limitations of Transforming Very High Body Mass Indexes into z -Scores among 8.7 Million 2- to 4-Year-Old Children

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Freedman, David S., Butte, Nancy F., Taveras, Elsie M., Goodman, Alyson B., Ogden, Cynthia L., Blanck, Heidi M.·2017·The Journal of Pediatrics
DOI 10.1016/j.jpeds.2017.03.039PMC PMC5572545
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Abstract

Objective To examine the associations among several body mass index (BMI) metrics (z-scores, percent of the 95th percentile (%BMI p95) and BMI minus 95th percentile (ΔBMI p95) as calculated in the growth charts from the Centers for Disease Control and Prevention (CDC). It is known that the widely used BMI z-scores (BMIz) and percentiles calculated from the growth charts can differ substantially from those that directly observed in the data for BMIs above the 97th percentile (z = 1.88). Study design Cross-sectional analyses of 8.7 million 2- to 4-year-old children who were examined from 2008 through 2011 in the CDC's Pediatric Nutrition Surveillance System. Results Because of the transformation used to calculate z-scores, the theoretical maximum BMIz varied by >3-fold across ages. This results in the conversion of very high BMIs into a narrow range of z-scores that varied by sex and age. Among children with severe obesity, levels of BMIz were only moderately correlated (r ~ 0.5) with %BMI p95 and ΔBMI p95. Among these children with severe obesity, BMIz levels could differ by more than 1 SD among children who had very similar levels of BMI, %BMI p95 and ΔBMI p95 due to differences in age or sex. Conclusions The effective upper limit of BMIz values calculated from the CDC growth charts, which varies by sex and age, strongly influences the calculation of z-scores for children with severe obesity. Expressing these very high BMIs relative to the CDC 95th percentile, either as a difference or percentage, would be preferable to using BMI-for-age, particularly when assessing the effectiveness of interventions.

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  • BMI is relatively simple to measure in adults and functionally sums a variety of complex body indicators.

    “BMI is relatively simple to measure in adults [4,5,6,7,8,9] and functionally sums a variety of complex body indicators.”

    From Advantages and Limitations of the Body Mass Index (BMI) to Assess Adult Obesity (2024) · cites this paper as [4]

    The Methods section (page unavailable) calculates BMI from weight and height, consistent with BMI being a relatively simple measure. But the paper studies young children and does not address ease of measurement in adults. Its Discussion (page unavailable) compares BMI metrics with adiposity measures; it does not establish that BMI sums a variety of body indicators. (LLM, conf=0.70)

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Research works printed but not linked: 1

  1. [14]Freedman DS Butte NF Taveras EM Lundeen EA Blanck HM Goodman AB BMI z-scores are a poor indicator of differences in adiposity among children and adolescents with severe obesity, NHANES 1999–2000 through 2013–14 In Press Obes (Silver Spring) 2017 PMC5373980 28245098

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Authors
Freedman, D. S., Butte, N. F., Taveras, E. M., Goodman, A. B., Ogden, C. L., & Blanck, H. M.
Affiliations
  • Centers for Disease Control and Prevention (US)
  • Baylor College of Medicine (US)
  • Massachusetts General Hospital (US)
Corresponding author
Freedman, David S.
ORCID
Venue
The Journal of Pediatrics
Publisher
Elsevier BV
Published
2017-09
Volume
188
Pages
50-56.e1
ISSN
0022-3476 (ISSN-L)
DOI
10.1016/j.jpeds.2017.03.039
PMC
PMC5572545
OpenAlex
W2606872751
Cited by
89
References
35
Citations by year
2026: 9 · 2025: 7 · 2024: 7 · 2023: 7 · 2022: 11 · 2021: 15 · 2020: 8 · 2019: 11 · 2018: 9 · 2017: 5
FWCI
8.47
Type
journal article
Language
en
Open access
Licence
www.elsevier.com/tdm/userlicense/1.0/ (tdm)
Locations
  • The Journal of Pediatrics (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • National Institutes of Health (CC999999)
  • National Institute of Diabetes and Digestive and Kidney Diseases (K24DK105989)
  • National Center for Chronic Disease Prevention and Health Promotion (U18DP003370)
Topics
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Obesity, Physical Activity, Diet
  • Health Sciences › Medicine › Physiology › Body Composition Measurement Techniques
  • Health Sciences › Health Professions › Pharmacy › Obesity and Health Practices
Keywords
BMI z-score, severe childhood obesity, body mass index for age, CDC growth charts, body mass index percentiles
MeSH terms
Child, Preschool, Cross-Sectional Studies, Female, Humans, Male, Nutrition Surveys, Body Mass Index, Overweight, Growth Charts, Pediatric Obesity

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