This article was published on August 6, 2022.
Here simple and brief explanation of what body mass index (BMI) is and why it matters.
Why use BMI instead of weight?
The same body weight in two persons would be interpreted differently depending on how tall the person is, right? That is why a person is said to be underweight, normal weight, overweight, or obese based not on body weight but on the body mass index (BMI). The BMI is calculated from a person’s height and weight.
How to calculate a person’s BMI
Here’s an easy way for you to get to a BMI calculator. In your browser’s window, type in:
simpleandpractical.com/bmi
This is a link I have created that will take you to a reputable BMI calculator.
Interpretation of BMI (Kg/m²)
< 18.5 — Underweight
18.5 to 24.9 — Normal or healthy weight
25 to 29.9 — Overweight
30 or more — Obese
The category of Obese is subclassified as follows:
30 to 34.9 — Class I obesity
35 to 39.9 — Class II obesity
More than 40 — Class III obesity
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References
Ben-Yacov L, Ainembabazi P, Stark AH. Is it time to update body mass index standards in the elderly or embrace measurements of body composition? Eur J Clin Nutr. 2017 Sep;71(9):1029-1032. doi: 10.1038/ejcn.2017.39. Epub 2017 Apr 12. PMID: 28402323.
Borga M, West J, Bell JD, Harvey NC, Romu T, Heymsfield SB, Dahlqvist Leinhard O. Advanced body composition assessment: from body mass index to body composition profiling. J Investig Med. 2018 Jun;66(5):1-9. doi: 10.1136/jim-2018-000722. Epub 2018 Mar 25. PMID: 29581385; PMCID: PMC5992366.
Egom EE, Pharithi RB, Shiwani HA, Khan B, Kruzliak P, El-Hiani Y, Maher V. Time to redefine body mass index categories in chronic diseases? Spotlight on obesity paradox. Int J Food Sci Nutr. 2018 Aug;69(5):513-523. doi: 10.1080/09637486.2017.1389859. Epub 2017 Oct 24. PMID: 29063824.
Gutin I. Body mass index is just a number: Conflating riskiness and unhealthiness in discourse on body size. Sociol Health Illn. 2021 Jul;43(6):1437-1453. doi: 10.1111/1467-9566.13309. Epub 2021 Jun 4. PMID: 34086365; PMCID: PMC8363552.
Khanna D, Peltzer C, Kahar P, Parmar MS. Body Mass Index (BMI): A Screening Tool Analysis. Cureus. 2022 Feb 11;14(2):e22119. doi: 10.7759/cureus.22119. PMID: 35308730; PMCID: PMC8920809.
Yu K, Liu X, Alhamzawi R, Becker F, Lord J. Statistical methods for body mass index: A selective review. Stat Methods Med Res. 2018 Mar;27(3):798-811. doi: 10.1177/0962280216643117. Epub 2016 Apr 11. PMID: 27072505.
Zierle-Ghosh A, Jan A. Physiology, Body Mass Index. 2021 Jul 22. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 30571077.
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Adolphe Quetelet, a statistician invented the basis of the BMI between 1830-1850 as he developed what he called “Social Physics“. But, BMI-adiposity relations appear to vary significantly across race/ethnic groups (Heymsfield SB. et al., 2016). There is an urgent need for accurate, practical, and affordable tools to measure fat and skeletal muscle ratio, and biomarkers that can better predict the risks of diseases and mortality (R. S. Ahima, M. A. Lazar. 2013). Measuring visceral and liver fat using indirect measurements (DEXA / DXA, MRI, CT…) is not a straightforward procedure in clinical practice or research; several variables may affect measurement accuracy and validity (Naboush A, Hamdy O. 2013). In the meantime, we should implement different methods to evaluate the health of our patients and determine the need for specific interventions.