Human body weight

Human body weight refers to a person's mass or weight. Body weight is measured in kilograms, a measure of mass, throughout the world, although in some countries such as the United States it is measured in pounds, or as in the United Kingdom, stones and pounds. Most hospitals, even in the United States, now use kilograms for calculations, but use kilograms and pounds together for other purposes.

Strictly speaking, body weight is the measurement of weight without items located on the person. Practically though, body weight may be measured with clothes on, but without shoes or heavy accessories such as mobile phones and wallets, and using manual or digital weighing scales. Excess or reduced body weight is regarded as an indicator of determining a person's health, with body volume measurement providing an extra dimension by calculating the distribution of body weight.

Estimation in children

There are a number of methods to estimate weight in children for circumstances (such as emergencies) when actual weight cannot be measured. Most involve a parent or health care provider guessing the child's weight through weight-estimation formulas. These formulas base their findings on the child's age and tape-based systems of weight estimation. Of the many formulas that have been used for estimating body weight, some include the APLS formula, the Leffler formula, and Theron formula.[1] There are also several types of tape-based systems for estimating children's weight, with the most well-known being the Broselow tape.[2] The Broselow tape is based on length with weight read from the appropriate color area. Newer systems, such as the PAWPER tape, make use of a simple two-step process to estimate weight: the length-based weight estimation is modified according to the child's body habitus to increase the accuracy of the final weight prediction.[3]

The Leffler formula is used for children 0–10 years of age.[1] In those less than a year old it is

${\displaystyle m={\tfrac {1}{2}}a_{m}+4}$

and for those 1–10 years old it is

${\displaystyle m=2a_{y}+10}$

where m is the number of kilograms the child weighs and am and ay respectively are the number of months or years old the child is.[1]

The Theron formula is

${\displaystyle m=e^{0.175571a_{y}+2.197099}}$

where m and ay are as above.[1]

Fluctuation

Body weight varies throughout the day, as the amount of water in the body is not constant. It changes frequently due to activities such as drinking, urinating, or exercise.[4][5] Professional sports participants may deliberately dehydrate themselves to enter a lower weight class, a practice known as weight cutting.[6]

Ideal body weight

Ideal body weight (IBW) was initially introduced by Devine in 1974 to allow estimation of drug clearances in obese patients;[7] researchers have since shown that the metabolism of certain drugs relates more to IBW than total body weight.[8] The term was based on the use of insurance data that demonstrated the relative mortality for males and females according to different height-weight combinations.

The most common estimation of IBW is by the Devine formula; other models exist and have been noted to give similar results.[8] Other methods used in estimating the ideal body weight are body mass index and the Hamwi method. The IBW is not the perfect fat measurement as it does not show the fat or muscle percentage in one's body. For example, athletes' results show that they are overweight when they are actually very fit and healthy. Machines like the dual-energy X-ray absorptiometry (DXA) can accurately measure the percentage and weight of fat, muscle, and bone in a body.

Devine formula

The Devine formula for calculating ideal body weight in adults is as follows:[8]

• Male ideal body weight = 50 kilograms (110 lb) + 0.9 kilograms (2.0 lb) × (height (cm) − 152)
• Female ideal body weight = 45.5 kilograms (100 lb) + 0.9 kilograms (2.0 lb) × (height (cm) − 152)

Hamwi method

The Hamwi method is used to calculate the ideal body weight of the general adult:[9]

• Male ideal body weight = 48 kilograms (106 lb) + 1.1 kilograms (2.4 lb) × (height (cm) − 152)
• Female ideal body weight = 45.4 kilograms (100 lb) + 0.9 kilograms (2.0 lb) × (height (cm) − 152)

Usage

Sports

Participants in sports such as boxing, mixed martial arts, wrestling, rowing, judo, Olympic weightlifting, and powerlifting are classified according to their body weight, measured in units of mass such as pounds or kilograms. See, e.g., wrestling weight classes, boxing weight classes, judo at the 2004 Summer Olympics, and boxing at the 2004 Summer Olympics.

Medicine

Ideal body weight, specifically the Devine formula, is used clinically for multiple reasons, most commonly in estimating renal function in drug dosing, and predicting pharmacokinetics in morbidly obese patients.[10][11]

Average weight around the world

By region

(millions)
Average weight Overweight population /
total population
Source
Africa53560.7 kg (133.8 lb)28.9%[12]
Asia2,81557.7 kg (127.2 lb)24.2%[12]
Europe60670.8 kg (156.1 lb)55.6%[12]
Latin America and the Caribbean38667.9 kg (149.7 lb)57.9%[12]
North America26380.7 kg (177.9 lb)73.9%[12]
Oceania2474.1 kg (163.4 lb)63.3%[12]
World4,63062.0 kg (136.7 lb)34.7%[12]

By country

Country Average male weight Average female weight Sample population /
age range
Methodology Year Source
Brazil72.7 kg (160.3 lb)62.5 kg (137.8 lb)20–74Measured2008–2009[13]
Belarus69 kg (152.1 lb)56 kg (123.5 lb)18+Measured2008[14]
Chile77.3 kg (170.4 lb)67.5 kg (148.8 lb)15+Measured2009–2010[15]
Finland82.1 kg (181 lb)Measured
France77.1 kg (170 lb)62.7 kg (138 lb)15+Measured2005[16]
Germany82.4 kg (181.7 lb)67.5 kg (148.8 lb)18+Measured2005[17]
South Korea68.6 kg (151.2 lb)56.5 kg (124.6 lb)18+Measured2007[18]
Sweden81.9 kg (180.6 lb)66.7 kg (147.0 lb)16–84Measured2003-2004[19]
UKWales84.0 kg (185.2 lb)69.0 kg (152.1 lb)16+Measured2009[20]
United States88.8 kg (195.8 lb)76.4 kg (168.4 lb)20+Measured2011-2014[21]

Global statistics

Researchers at the London School of Hygiene & Tropical Medicine published a study of average weights of adult humans in the journal BMC Public Health and at the United Nations conference Rio+20.[22]

References

1. So TY, Farrington E, Absher RK (June 2009). "Evaluation of the accuracy of different methods used to estimate weights in the pediatric population". Pediatrics. 123 (6): e1045–51. doi:10.1542/peds.2008-1968. PMID 19482737.
2. Lubitz, Deborah; Seidel, JS; Chameides, L; Luten, RC; Zaritsky, AL; Campbell, FW (1988). "A rapid method for estimating weight and resuscitation drug dosages from length in the pediatric age group". Ann Emerg Med. 17 (6): 576–81. doi:10.1016/S0196-0644(88)80396-2. PMID 3377285.
3. Wells, Mike (2011). "Clinical: The PAWPER Tape". Sanguine. 1 (2). Retrieved 13 June 2013.
4. Smith, Jessica (16 May 2013). "Stop Hating the Scale". Shape Magazine. Retrieved 23 January 2017.
5. Talens, Dick (30 November 2014). "What the Number on the Scale Really Means". Greatist. Retrieved 23 January 2017.
6. Lee, Orion. "Making Weight: Why Fighters Cut Weight and 3 Tips for Doing It". Breaking Muscle. Retrieved 23 January 2017.
7. Devine, Ben J (1974). "Gentamicin therapy". Drug Intell Clin Pharm. 8 (11): 650–5. doi:10.1177/106002807400801104.
8. Pai, Manjunath P; Paloucek, Frank P (September 2000). "The Origin of the "Ideal" Body Weight Equations". The Annals of Pharmacotherapy. 34 (9): 1066–1069. doi:10.1345/aph.19381. PMID 10981254.
9. Geriatric Nutrition Handbook. p. 15. ISBN 978-0412136412.
10. Jones, Graham RD (2011). "Estimating Renal Function for Drug Dosing Decisions". The Clinical Biochemist Reviews. 32 (2): 81–88. PMC 3100285. PMID 21611081.
11. van Kraligen, S; van de Garde, EMW; Knibbe, CAJ; Diepstraten, J; Wiezer, MJ; van Ramshorst, B; Dongen, EPA (2011). "Comparative evaluation of atracurium dosed on ideal body weight vs. total body weight in morbidly obese patients". British Journal of Clinical Pharmacology. 71 (1): 34–40. doi:10.1111/j.1365-2125.2010.03803.x. PMC 3018024. PMID 21143499.
12. Walpole, Sarah C; Prieto-Merino, David; Edwards, Phil; Cleland, John; Stevens, Gretchen; Roberts, Ian; et al. (18 June 2012). "The weight of nations: an estimation of adult human biomass". BMC Public Health. BMC Public Health 2012, 12:439. 12 (1): 439. doi:10.1186/1471-2458-12-439. PMC 3408371. PMID 22709383. Retrieved 12 July 2012.
13. Do G1, em São Paulo (27 August 2010). "G1 - Metade dos adultos brasileiros está acima do peso, segundo IBGE - notícias em Brasil". G1.globo.com. Retrieved 13 July 2012.
14. Отдел антропологии и экологии Института истории НАН Беларуси (21 September 2012). "Чем отличаются "вчерашние" белорусы от "сегодняшних"?". news.tut.by. Retrieved 11 October 2019.
15. Encuesta Nacional de Salud 2009–2010 Archived 12 March 2011 at the Wayback Machine (p. 81)
16. © wissenmedia in der inmediaONE GmbH, Gütersloh/München. "Bauer sucht Frau aus dem Lexikon" (in German). wissen.de. Retrieved 13 July 2012.
17. "The Chosun Ilbo (English Edition): Daily News from Korea - Average Korean Now Overweight". English.chosun.com. 27 July 2009. Retrieved 13 July 2012.
18. "6 kilo mer man och 4 kilo mer kvinna" (in Swedish). Archived from the original on 27 February 2014. Retrieved 27 February 2014.
19. "The Welsh Health Survey 2009, p. 58" (PDF). Wales.gov.uk. 15 September 2010. Retrieved 22 January 2011.
20. "Anthropometric Reference Data for Children and Adults: United States, 2011–2014" (PDF). Retrieved 10 January 2018.
21. Data extracted from "The world's fattest countries: how do you compare?". The Daily Telegraph. 21 June 2012. Retrieved 22 September 2016.