The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations
Background: Critical cut-off values of BMI-for-age z-scores (BAZ) are used to define “thinness”, “overweight” and “obesity”, but the validity of these cut-off values needs to be questioned in populations that are shorter or taller than the reference. We hypothesized that the prevalence of thinness,...
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| Format: | Article |
| Language: | English |
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Universitätsverlag Potsdam
2022-08-01
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| Series: | Human Biology and Public Health |
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| Online Access: | https://www.human-biology-and-public-health.org/index.php/hbph/article/view/21 |
| _version_ | 1827298923640782848 |
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| author | Michael Hermanussen Masiar Novine Christiane Scheffler Detlef Groth |
| author_facet | Michael Hermanussen Masiar Novine Christiane Scheffler Detlef Groth |
| author_sort | Michael Hermanussen |
| collection | DOAJ |
| description |
Background: Critical cut-off values of BMI-for-age z-scores (BAZ) are used to define “thinness”, “overweight” and “obesity”, but the validity of these cut-off values needs to be questioned in populations that are shorter or taller than the reference. We hypothesized that the prevalence of thinness, overweight, and obesity depends on population height and performed a random simulation.
Methods: We created virtual child populations aged 2-10 years with normally distributed height expressed as height-for-age z-scores (HAZ) and weight expressed as weight-for-age z-score (WAZ), based on WHO growth standards and references, with a correlation r=0.7 between height and weight. We adjusted weight-for-height and calculated BAZ.
Results: BAZ depends on height and age. In short children (mean HAZ=-2 to HAZ=-3), the prevalence of thinness falls to less than 1% in the youngest and rises up to 10% (mean HAZ=-2) and up to 13% (mean HAZ=-3) at age 10 years. The prevalence of obesity rises to up to 7% in the shortest and youngest and falls close to zero at age 10. Short young children and tall older children are more prone to be misclassified as overweight.
Conclusions: The prevalence of thinness, overweight and obesity depends on height and age. The coexistence of being short and being overweight – currently referred to as “double burden of malnutrition” – needs consideration as to what extent this condition is a health issue or reflects calculation artefacts. The arithmetic dilemma particularly affects young children in short populations. We suggest abstaining from defining “thinness”, “overweight”, or “obesity” by BMI z-scores. Different states of under- and malnutrition should rather be classified by direct or indirect measures of body fat.
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| first_indexed | 2024-04-24T15:24:20Z |
| format | Article |
| id | doaj.art-3bc741531cfb4069be985952856a8e97 |
| institution | Directory Open Access Journal |
| issn | 2748-9957 |
| language | English |
| last_indexed | 2024-04-24T15:24:20Z |
| publishDate | 2022-08-01 |
| publisher | Universitätsverlag Potsdam |
| record_format | Article |
| series | Human Biology and Public Health |
| spelling | doaj.art-3bc741531cfb4069be985952856a8e972024-04-02T07:03:55ZengUniversitätsverlag PotsdamHuman Biology and Public Health2748-99572022-08-01110.52905/hbph2022.1.21The arithmetic dilemma when defining thinness, overweight and obesity in stunted populationsMichael Hermanussen0https://orcid.org/0000-0003-4037-1597Masiar Novine1https://orcid.org/0000-0001-9687-8675Christiane Scheffler2https://orcid.org/0000-0003-1954-7578Detlef Groth3https://orcid.org/0000-0002-9441-3978Aschauhof 3, 24340 Eckernförde – Altenhof, GermanyUniversity of Potsdam, Bioinformatics, 14476 Potsdam-Golm, GermanyUniversity of Potsdam, Human Biology, 14469 Potsdam, GermanyUniversity of Potsdam, Bioinformatics, 14476 Potsdam-Golm, Germany Background: Critical cut-off values of BMI-for-age z-scores (BAZ) are used to define “thinness”, “overweight” and “obesity”, but the validity of these cut-off values needs to be questioned in populations that are shorter or taller than the reference. We hypothesized that the prevalence of thinness, overweight, and obesity depends on population height and performed a random simulation. Methods: We created virtual child populations aged 2-10 years with normally distributed height expressed as height-for-age z-scores (HAZ) and weight expressed as weight-for-age z-score (WAZ), based on WHO growth standards and references, with a correlation r=0.7 between height and weight. We adjusted weight-for-height and calculated BAZ. Results: BAZ depends on height and age. In short children (mean HAZ=-2 to HAZ=-3), the prevalence of thinness falls to less than 1% in the youngest and rises up to 10% (mean HAZ=-2) and up to 13% (mean HAZ=-3) at age 10 years. The prevalence of obesity rises to up to 7% in the shortest and youngest and falls close to zero at age 10. Short young children and tall older children are more prone to be misclassified as overweight. Conclusions: The prevalence of thinness, overweight and obesity depends on height and age. The coexistence of being short and being overweight – currently referred to as “double burden of malnutrition” – needs consideration as to what extent this condition is a health issue or reflects calculation artefacts. The arithmetic dilemma particularly affects young children in short populations. We suggest abstaining from defining “thinness”, “overweight”, or “obesity” by BMI z-scores. Different states of under- and malnutrition should rather be classified by direct or indirect measures of body fat. https://www.human-biology-and-public-health.org/index.php/hbph/article/view/21BMIstuntingprevalencethinnessobesitymisclassification |
| spellingShingle | Michael Hermanussen Masiar Novine Christiane Scheffler Detlef Groth The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations Human Biology and Public Health BMI stunting prevalence thinness obesity misclassification |
| title | The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations |
| title_full | The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations |
| title_fullStr | The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations |
| title_full_unstemmed | The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations |
| title_short | The arithmetic dilemma when defining thinness, overweight and obesity in stunted populations |
| title_sort | arithmetic dilemma when defining thinness overweight and obesity in stunted populations |
| topic | BMI stunting prevalence thinness obesity misclassification |
| url | https://www.human-biology-and-public-health.org/index.php/hbph/article/view/21 |
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