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Human body weight
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| Human body weight |
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Human body weight is a person's mass or weight.
Strictly speaking, body weight is the measurement of mass 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.
Average adult human male weight varies by continent, from about 50 kg (110 lb) in Asia and Africa to about 60 kg (130 lb) in North America, with men on average weighing more than women.
Estimation in children
[edit]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 Advanced Pediatric Life Support formula, the Leffler formula, and Theron formula.[1] There are also several types of tape-based systems for estimating children's weight, with the best-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
and for those 1–10 years old, it is
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
where m and ay are as above.[1]
Fluctuation
[edit]Body weight varies in small amounts throughout the day, as the amount of water in the body is not constant. It changes due to activities such as drinking, urinating, or exercise.[4] Professional sports participants may deliberately dehydrate themselves to enter a lower weight class, a practice known as weight cutting.[5]
Ideal body weight
[edit]Ideal body weight (IBW) was initially introduced by Ben J. Devine in 1974 to allow estimation of drug clearances in obese patients;[6] researchers have since shown that the metabolism of certain drugs relates more to IBW than total body weight.[7] 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.[7] 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 may show that they are overweight when they are actually very fit and healthy. Machines like the dual-energy X-ray absorptiometry can accurately measure the percentage and weight of fat, muscle, and bone in a body.
Devine formula
[edit]The Devine formula for calculating ideal body weight in adults is as follows:[7]
- 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
[edit]The Hamwi method is used to calculate the ideal body weight of the general adult:[8]
- 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
[edit]Sports
[edit]Many disciplines in weightlifting or combat sports separate competitors into weight classes.
Medicine
[edit]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.[9][10]
Average weight around the world
[edit]By region
[edit]Data from 2005:
| Region | Adult population (millions) |
Average weight | % Overweight |
Ref |
|---|---|---|---|---|
| Africa | 535 | 60.7 kg (133.8 lb) | 28.9% | [11] |
| Asia | 2,815 | 57.7 kg (127.2 lb) | 24.2% | [11] |
| Europe | 606 | 70.8 kg (156.1 lb) | 55.6% | [11] |
| Latin America and the Caribbean |
386 | 67.9 kg (149.7 lb) | 57.9% | [11] |
| North America | 263 | 80.7 kg (177.9 lb) | 73.9% | [11] |
| Oceania | 24 | 74.1 kg (163.4 lb) | 63.3% | [11] |
| World | 4,630 | 62.0 kg (136.7 lb) | 34.7% | [11] |
By country
[edit]| Country | Average male weight | Average female weight | Sample population / age range |
Method | Year | Ref |
|---|---|---|---|---|---|---|
| 69.2 kg (152.6 lb) | 62.6 kg (138.0 lb) | 18–69 | Measured | 2018 | [12] | |
| 68.7 kg (151.5 lb) | 65.1 kg (143.5 lb) | 25–64 | Measured | 2005 | [13] | |
| 74.6 kg (164.5 lb) | 66.4 kg (146.4 lb) | 18–69 | Measured | 2016 | [14] | |
| 87.0 kg (191.8 lb) | 71.8 kg (158.3 lb) | 18+ | Measured | 2018 | [15] | |
| 72.1 kg (159.0 lb) | 65.7 kg (144.8 lb) | 16+ | Measured | 2005 | [16] | |
| 55.2 kg (121.7 lb) | 49.8 kg (109.8 lb) | 25+ | Measured | 2009–2010 | [17] | |
| 69 kg (152.1 lb) | 56 kg (123.5 lb) | 18+ | Measured | 2008 | [18] | |
| 74.2 kg (163.6 lb) | 70.5 kg (155.4 lb) | 20+ | Measured | 2010 | [19] | |
| 63.7 kg (140.4 lb) | 60.9 kg (134.3 lb) | 18–69 | Measured | 2015 | [20] | |
| 63.2 kg (139.3 lb) | 57.4 kg (126.5 lb) | 18–69 | Measured | 2014 | [21] | |
| 63.6 kg (140.2 lb) | 64.3 kg (141.8 lb) | 15–69 | Measured | 2014 | [22] | |
| 72.7 kg (160.3 lb) | 62.5 kg (137.8 lb) | 20–74 | Measured | 2008–2009 | [23] | |
| 74.1 kg (163.4 lb) | 62.9 kg (138.7 lb) | 19+ | Measured | 2010–2011 | [24] | |
| 76.9 kg (169.5 lb) | 69.1 kg (152.3 lb) | 21–59 | Self-reported | 2021 | [25] | |
| 65.2 kg (143.7 lb) | 59.0 kg (130.1 lb) | 25–64 | Measured | 2013 | [26] | |
| 56.8 kg (125.2 lb) | 50.8 kg (112.0 lb) | 25–64 | Measured | 2010 | [27] | |
| 68.3 kg (150.6 lb) | 67.0 kg (147.7 lb) | 15+ | Measured | 2003 | [28] | |
| 84.6 kg (187 lb) | 70.1 kg (155 lb) | 18–79 | Measured | 2007–2009 | [29] | |
| 77.3 kg (170.4 lb) | 67.5 kg (148.8 lb) | 15+ | Measured | 2009–2010 | [30] | |
| 76.6 kg (168.9 lb) | 64.9 kg (143.1 lb) | 20+ | Measured | 2010 | [31] | |
| 92.1 kg (203.0 lb) | 73.8 kg (162.7 lb) | 25–64 | Measured | 2016–2017 | [32] | |
| 84.4 kg (186.1 lb) | 71.2 kg (157.0 lb) | 18+ | Measured | 2003–2010 | [33] | |
| 77.1 kg (170 lb) | 62.7 kg (138 lb) | 15+ | Measured | 2005 | [34] | |
| 84.4 kg (186.1 lb) | 73.6 kg (162.3 lb) | 18–69 | Measured | 2016 | [35] | |
| 85.9 kg (189.4 lb) | 69.2 kg (152.6 lb) | 18+ | Self-reported | 2021 | [36] | |
| 65.0 kg (143.3 lb) | 55.0 kg (121.3 lb) | 16+ | Measured | 2020 | [37] | |
| 86.6 kg (190.9 lb) | 71.6 kg (157.9 lb) | 18+ | Self-reported | 2020 | [38] | |
| 74.9 kg (165.1 lb) | 68.1 kg (150.1 lb) | 18+ | Measured | 2017 | [39] | |
| 66.0 kg (145.5 lb) | 59.0 kg (130.1 lb) | 18–69 | Measured | 2013–2014 | [40] | |
| 62.5 kg (137.8 lb) | 56.8 kg (125.2 lb) | 15–64 | Measured | 2007–2008 | [41] | |
| 84.6 kg (186.5 lb) | 73.4 kg (161.8 lb) | 18–64 | Measured | 2012 | [42] | |
| 70.6 kg (155.6 lb) | 60.2 kg (132.7 lb) | 19+ | Measured | 2018 | [43] | |
| 58.4 kg (128.7 lb) | 55.9 kg (123.2 lb) | 15–64 | Measured | 2012–2013 | [44] | |
| 84.5 kg (186.3 lb) | 83.0 kg (183.0 lb) | 25–64 | Measured | 2007–2008 | [45] | |
| 77.3 kg (170.4 lb) | 71.7 kg (158.1 lb) | 25–64 | Measured | 2005 | [46] | |
| 84.6 kg (186.5 lb) | 70.0 kg (154.3 lb) | 20+ | Measured | 2013 | [47] | |
| 62.0 kg (136.7 lb) | 59.0 kg (130.1 lb) | 25–64 | Measured | 2009 | [48] | |
| 75.3 kg (166.0 lb) | 70.4 kg (155.2 lb) | 25–64 | Measured | 2006 | [49] | |
| 73.34 kg (161.7 lb) | 58.29 kg (128.5 lb) | 18+ | Measured | 2019 | [50] | |
| 82.4 kg (181.7 lb) | 66.6 kg (146.8 lb) | 18–64 | Measured | 2013 | [51] | |
| 61.4 kg (135.4 lb) | 54.6 kg (120.4 lb) | 18–69 | Measured | 2014–2015 | [52] | |
| 65.4 kg (144.2 lb) | 61.6 kg (135.8 lb) | 18–69 | Measured | 2016 | [53] | |
| 81.9 kg (180.6 lb) | 66.7 kg (147.0 lb) | 16–84 | Measured | 2003–2004 | [54] | |
| 63.2 kg (139.3 lb) | 60.0 kg (132.3 lb) | 15–64 | Measured | 2010 | [55] | |
| 99.4 kg (219.1 lb) | 97.7 kg (215.4 lb) | 25–64 | Measured | 2012 | [56] | |
| 76.7 kg (169.1 lb) | 71.1 kg (156.7 lb) | 15–64 | Measured | 2011 | [57] | |
| 78.0 kg (172.0 lb) | 70.1 kg (154.5 lb) | 15+ | Measured | 2017 | [58] | |
| 76.6 kg (168.9 lb) | 67.4 kg (148.6 lb) | 18–69 | Measured | 2018 | [59] | |
| 85.4 kg (188.3 lb) | 72.1 kg (159.0 lb) | 16+ | Measured | 2019 | [60] | |
| 84.0 kg (185.2 lb) | 69.0 kg (152.1 lb) | 16+ | Measured | 2009 | [61] | |
| 80.0 kg (176.4 lb) | 71.0 kg (156.5 lb) | 18+ | Measured | 2020 | [62] | |
| 90.6 kg (199.7 lb) | 77.5 kg (170.9 lb) | 20+ | Measured | 2015–2018 | [63] |
Global statistics
[edit]Researchers at the London School of Hygiene and 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.[64]
| Rank | Country | Kilograms | Pounds | Relative size |
|---|---|---|---|---|
| 1 | Micronesia | 87.398 | 192.68 | |
| 2 | Tonga | 87.344 | 192.56 | |
| 3 | United States | 81.928 | 180.62 | |
| 4 | Samoa | 78.544 | 173.16 | |
| 5 | Kuwait | 77.791 | 171.50 | |
| 6 | Australia | 77.356 | 170.54 | |
| 7 | Malta | 76.956 | 169.66 | |
| 8 | Qatar | 76.866 | 169.46 | |
| 9 | Croatia | 76.412 | 168.46 | |
| 10 | United Kingdom | 75.795 | 167.10 | |
| 11 | UAE | 75.532 | 166.52 | |
| 12 | Greece | 75.038 | 165.43 | |
| 13 | Cyprus | 74.802 | 164.91 | |
| 14 | Egypt | 74.271 | 163.74 | |
| 15 | Barbados | 73.831 | 162.77 | |
| 16 | Belarus | 73.663 | 162.40 | |
| 17 | Bahrain | 73.550 | 162.15 | |
| 18 | Germany | 73.042 | 161.03 | |
| 19 | Solomon Islands | 72.797 | 160.49 | |
| 20 | Austria | 72.743 | 160.37 | |
| 21 | Saudi Arabia | 72.638 | 160.14 | |
| 22 | Iceland | 72.584 | 160.02 | |
| 23 | Trinidad & Tobago | 72.538 | 159.92 | |
| 24 | Argentina | 72.434 | 159.69 | |
| 25 | Bahamas | 72.380 | 159.57 | |
| 26 | Finland | 72.348 | 159.50 | |
| 27 | Israel | 71.912 | 158.54 | |
| 28 | Czech Rep. | 71.640 | 157.94 | |
| 29 | New Zealand | 71.631 | 157.92 | |
| 30 | Bulgaria | 71.459 | 157.54 | |
| 31 | Russia | 71.418 | 157.45 | |
| 32 | Slovenia | 71.200 | 156.97 | |
| 33 | Slovakia | 71.060 | 156.66 | |
| 34 | Albania | 71.019 | 156.57 | |
| 35 | Bosnia | 71.001 | 156.53 | |
| 36 | Switzerland | 70.987 | 156.50 | |
| 37 | Rep. of Moldova | 70.978 | 156.48 | |
| 38 | Venezuela | 70.788 | 156.06 | |
| 39 | Chile | 70.593 | 155.63 | |
| 40 | Georgia | 70.561 | 155.56 | |
| 41 | Spain | 70.556 | 155.55 | |
| 42 | Azerbaijan | 70.484 | 155.39 | |
| 43 | Hungary | 70.443 | 155.30 | |
| 44 | Libya | 70.429 | 155.27 | |
| 45 | Luxembourg | 70.270 | 154.92 | |
| 46 | Tajikistan | 70.234 | 154.84 | |
| 47 | Portugal | 70.193 | 154.75 | |
| 48 | Lithuania | 70.153 | 154.66 | |
| 49 | Grenada | 70.139 | 154.63 | |
| 50 | Panama | 69.939 | 154.19 | |
| 51 | Ireland | 69.926 | 154.16 | |
| 52 | Canada | 69.767 | 153.81 | |
| 53 | Jordan | 69.649 | 153.55 | |
| 54 | St Vincent & Grenadines | 69.590 | 153.42 | |
| 55 | Belize | 69.377 | 152.95 | |
| 56 | Poland | 69.241 | 152.65 | |
| 57 | Macedonia | 69.209 | 152.58 | |
| 58 | Italy | 69.205 | 152.57 | |
| 59 | Jamaica | 69.064 | 152.26 | |
| 60 | Sweden | 69.064 | 152.26 | |
| 61 | Turkey | 69.046 | 152.22 | |
| 62 | Cuba | 69.037 | 152.20 | |
| 63 | Mexico | 69.023 | 152.17 | |
| 64 | Mongolia | 68.910 | 151.92 | |
| 65 | Uruguay | 68.873 | 151.84 | |
| 66 | Belgium | 68.801 | 151.68 | |
| 67 | Suriname | 68.778 | 151.63 | |
| 68 | Latvia | 68.778 | 151.63 | |
| 69 | Norway | 68.774 | 151.62 | |
| 70 | Netherlands | 68.746 | 151.56 | |
| 71 | Ukraine | 68.674 | 151.40 | |
| 72 | Guatemala | 68.579 | 151.19 | |
| 73 | Saint Lucia | 68.438 | 150.88 | |
| 74 | Armenia | 68.424 | 150.85 | |
| 75 | Nicaragua | 68.415 | 150.83 | |
| 76 | Vanuatu | 68.229 | 150.42 | |
| 77 | El Salvador | 68.220 | 150.40 | |
| 78 | Lebanon | 68.170 | 150.29 | |
| 79 | Ecuador | 68.166 | 150.28 | |
| 80 | Fiji | 68.048 | 150.02 | |
| 81 | Bolivia | 68.034 | 149.99 | |
| 82 | Dominican Rep. | 67.993 | 149.90 | |
| 83 | Denmark | 67.957 | 149.82 | |
| 84 | Costa Rica | 67.853 | 149.59 | |
| 85 | Tunisia | 67.726 | 149.31 | |
| 86 | Iran | 67.608 | 149.05 | |
| 87 | Turkmenistan | 67.563 | 148.95 | |
| 88 | Paraguay | 67.445 | 148.69 | |
| 89 | Peru | 67.440 | 148.68 | |
| 90 | Syria | 67.422 | 148.64 | |
| 91 | Guyana | 67.032 | 147.78 | |
| 92 | France | 66.782 | 147.23 | |
| 93 | Estonia | 66.732 | 147.12 | |
| 94 | Equatorial Guinea | 66.451 | 146.50 | |
| 95 | Romania | 66.401 | 146.39 | |
| 96 | Colombia | 66.370 | 146.32 | |
| 97 | Uzbekistan | 66.351 | 146.28 | |
| 98 | Kazakhstan | 66.265 | 146.09 | |
| 99 | Brazil | 66.093 | 145.71 | |
| 100 | Mauritius | 66.052 | 145.62 | |
| 101 | Iraq | 66.034 | 145.58 | |
| 102 | Lesotho | 65.966 | 145.43 | |
| 103 | Honduras | 65.834 | 145.14 | |
| 104 | Oman | 65.803 | 145.07 | |
| 105 | South Africa | 65.667 | 144.77 | |
| 106 | Kyrgyzstan | 65.413 | 144.21 | |
| 107 | Botswana | 65.045 | 143.40 | |
| 108 | Cameroon | 64.832 | 142.93 | |
| 109 | Morocco | 64.764 | 142.78 | |
| 110 | South Korea | 64.392 | 141.96 | |
| 111 | Mauritania | 64.179 | 141.49 | |
| 112 | Algeria | 63.639 | 140.30 | |
| 113 | Gabon | 62.845 | 138.55 | |
| 114 | Ghana | 62.491 | 137.77 | |
| 115 | Cape Verde | 62.296 | 137.34 | |
| 116 | Papua New Guinea | 62.251 | 137.24 | |
| 117 | Eswatini | 62.097 | 136.90 | |
| 118 | Djibouti | 62.015 | 136.72 | |
| 119 | Haiti | 61.698 | 136.02 | |
| 120 | Comoros | 61.044 | 134.58 | |
| 121 | Zimbabwe | 61.022 | 134.53 | |
| 122 | Brunei | 60.945 | 134.36 | |
| 123 | Sierra Leone | 60.854 | 134.16 | |
| 124 | Nigeria | 60.745 | 133.92 | |
| 125 | Malaysia | 60.682 | 133.78 | |
| 126 | China | 60.555 | 133.50 | |
| 127 | Angola | 60.387 | 133.13 | |
| 128 | Senegal | 60.373 | 133.10 | |
| 129 | Benin | 60.282 | 132.90 | |
| 130 | Mali | 60.078 | 132.45 | |
| 131 | Yemen | 59.802 | 131.84 | |
| 132 | Philippines | 59.715 | 131.65 | |
| 133 | Namibia | 59.584 | 131.36 | |
| 134 | Sudan | 59.407 | 130.97 | |
| 135 | Togo | 59.280 | 130.69 | |
| 136 | Guinea | 59.112 | 130.32 | |
| 137 | Japan | 59.017 | 130.11 | |
| 138 | Pakistan | 58.976 | 130.02 | |
| 139 | Singapore | 58.935 | 129.93 | |
| 140 | Thailand | 58.786 | 129.60 | |
| 141 | Côte d'Ivoire | 58.727 | 129.47 | |
| 142 | Laos | 58.436 | 128.83 | |
| 143 | Chad | 58.196 | 128.30 | |
| 144 | Niger | 57.933 | 127.72 | |
| 145 | Maldives | 57.647 | 127.09 | |
| 146 | São Tomé and Príncipe | 57.561 | 126.90 | |
| 147 | Burkina Faso | 57.456 | 126.67 | |
| 148 | Congo | 57.384 | 126.51 | |
| 149 | Tanzania | 57.293 | 126.31 | |
| 150 | Gambia | 57.071 | 125.82 | |
| 151 | Uganda | 57.007 | 125.68 | |
| 152 | Afghanistan | 56.935 | 125.52 | |
| 153 | Malawi | 56.681 | 124.96 | |
| 154 | Rwanda | 56.635 | 124.86 | |
| 155 | Myanmar | 56.354 | 124.24 | |
| 156 | Kenya | 56.264 | 124.04 | |
| 157 | Guinea-Bissau | 56.087 | 123.65 | |
| 158 | Mozambique | 55.955 | 123.36 | |
| 159 | Central African Rep. | 55.946 | 123.34 | |
| 160 | Zambia | 55.910 | 123.26 | |
| 161 | Cambodia | 55.742 | 122.89 | |
| 162 | Liberia | 55.533 | 122.43 | |
| 163 | Somalia | 55.375 | 122.08 | |
| 164 | Madagascar | 55.157 | 121.60 | |
| 165 | Burundi | 54.127 | 119.33 | |
| 166 | Congo | 53.501 | 117.95 | |
| 167 | Ethiopia | 53.057 | 116.97 | |
| 168 | India | 52.943 | 116.72 | |
| 169 | North Korea | 52.589 | 115.94 | |
| 170 | Indonesia | 52.467 | 115.67 | |
| 171 | Eritrea | 52.041 | 114.73 | |
| 172 | Timor-Leste | 51.950 | 114.53 | |
| 173 | Bhutan | 51.142 | 112.75 | |
| 174 | Vietnam | 50.725 | 111.83 | |
| 175 | Nepal | 50.476 | 111.28 | |
| 176 | Sri Lanka | 50.421 | 111.16 | |
| 177 | Bangladesh | 49.591 | 109.33 | |
| — | world average | 61.997 | 136.68 |
See also
[edit]- Anthropometry
- Bergmann's rule
- Birth weight
- Body mass index (BMI)
- Classification of obesity
- Emaciation
- Hesse's Rule
- History of anthropometry
- Human height
- List of heaviest people
- Obesity
- Overweight
- Set point theory
- Stone (unit) § human body weight
- Thermoregulation in humans
- Underweight
- Weight loss and weight gain
- Weight phobia (disambiguation)
- Exercise paradox
References
[edit]- ^ a b c d 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. S2CID 6009482.
- ^ 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.
- ^ Wells, Mike (2011). "Clinical: The PAWPER Tape". Sanguine. 1 (2). Retrieved 13 June 2013.
- ^ Smith, Jessica (16 May 2013). "Stop Hating the Scale". Shape Magazine. Retrieved 23 January 2017.
- ^ Lee, Orion (4 August 2013). "Making Weight: Why Fighters Cut Weight and 3 Tips for Doing It". Breaking Muscle. Retrieved 23 January 2017.
- ^ McCarron, Margaret M.; Devine, Ben J. (1 November 1974). "Clinical Pharmacy: Case Studies: Case Number 25 Gentamicin Therapy". Drug Intell Clin Pharm. 8 (11): 650–5. doi:10.1177/106002807400801104. S2CID 80397846.
- ^ a b c 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. S2CID 6213850.
- ^ Bartlett, Stephen; Marian, Mary; Taren, Douglas; Muramoto, Myra L. (30 November 1997). Geriatric Nutrition Handbook. Jones & Bartlett Learning. p. 15. ISBN 978-0-412-13641-2.
- ^ Jones, Graham RD (2011). "Estimating Renal Function for Drug Dosing Decisions". The Clinical Biochemist Reviews. 32 (2): 81–88. PMC 3100285. PMID 21611081.
- ^ 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.
- ^ a b c d e f g 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. 12 (1). BMC Public Health 2012, 12:439: 439. doi:10.1186/1471-2458-12-439. PMC 3408371. PMID 22709383.
- ^ "Afghanistan - STEPS 2018, National Non-Communicable Disease Risk Factors Survey". World Health Organization. 2018. p. 40. AFG_2018_STEPS_v01.
- ^ "Algeria STEPS Survey 2002" (PDF). World Health Organization. 2005. p. 70.
- ^ "Prevalence of noncommunicable disease risk factors in the Republic of Armenia, STEPS National Survey 2016" (PDF). National Institute of Health. 2018. p. 167.
- ^ "National Health Survey: First results, Body Mass Index, waist circumference, height and weight - Australia". Australian Bureau of Statistics. 2018.
- ^ "Azerbaijan State Statistics Committee, 2005". Today.az. 7 May 2005. Retrieved 22 January 2011.
- ^ "Non-Communicable Disease Risk Factor Survey Bangladesh" (PDF). World Health Organization. 2010. p. 120.
- ^ Отдел антропологии и экологии Института истории НАН Беларуси (21 September 2012). "Чем отличаются "вчерашние" белорусы от "сегодняшних"?". news.tut.by. Archived from the original on 11 June 2020. Retrieved 11 October 2019.
- ^ "The Central America Diabetes Initiative (CAMDI), Survey of Diabetes, Hypertension and Chronic Disease Risk Factors" (PDF). Pan American Health Organization. 2011. pp. 25–26, 61.
- ^ "Rapport final de l'enquête pour la surveillance des facteurs de risque des maladies non transmissibles par l'approche STEPSwise de l'OMS ENQUETE STEPS 2015 au Bénin" (PDF). World Health Organization (in French). 2016. p. 90.
- ^ "National survey for noncommunicable disease risk factors and mental health using WHO STEPS approach in Bhutan" (PDF). World Health Organization. 2014. p. 103.
- ^ "Botswana STEPS survey report on non-communicable disease risk factors" (PDF). World Health Organization. 2014. p. 94.
- ^ 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.
{{cite web}}: CS1 maint: numeric names: authors list (link) - ^ "The 2nd National Health and Nutritional Status Survey (NHANSS)" (PDF). Ministry of Health Brunei Darussalam. 2014. p. 59.
- ^ Bulgarian Academy of Sciences (2021). Енциклопедия България [Bulgarian Encyclopedia] (in Bulgarian). Книгомания. ISBN 978-619-195-294-6.
- ^ "Rapport de L'enquete Nationale sur la prevalence des principaux facteurs de risques communs aux maldies non transmissibles au Burkina Faso" (PDF). World Health Organization (in French). 2014. p. 38.
- ^ "Prevalence of Non-communicable Disease Risk Factors in Cambodia" (PDF). World Health Organization. 2010. p. 157.
- ^ Kamadjeu, Raoul M; Edwards, Richard; Atanga, Joseph S; Kiawi, Emmanuel C; Unwin, Nigel; Mbanya, Jean-Claude (December 2006). "Anthropometry measures and prevalence of obesity in the urban adult population of Cameroon: an update from the Cameroon Burden of Diabetes Baseline Survey". BMC Public Health. 6 (1): 228. doi:10.1186/1471-2458-6-228. ISSN 1471-2458. PMC 1579217. PMID 16970806.
- ^ Shields, Margot; Connor Gorber, Sarah; Janssen, Ian; Tremblay, Mark S. (November 2011). "Bias in self-reported estimates of obesity in Canadian health surveys: an update on correction equations for adults". Health Reports. 22 (3): 35–45. ISSN 0840-6529. PMID 22106788.
- ^ Encuesta Nacional de Salud 2009–2010 Archived 12 March 2011 at the Wayback Machine (p. 81)
- ^ "The Central America Diabetes Initiative (CAMDI), Survey of Diabetes, Hypertension and Chronic Disease Risk Factors" (PDF). Pan American Health Organization. 2011. pp. 25–26, 61.
- ^ Cífková, Renata; Bruthans, Jan; Wohlfahrt, Peter; Krajčoviechová, Alena; Šulc, Pavel; Jozífová, Marie; Eremiášová, Lenka; Pudil, Jan; Linhart, Aleš; Widimský, Jiří; Filipovský, Jan (11 May 2020). Shimosawa, Tatsuo (ed.). "30-year trends in major cardiovascular risk factors in the Czech population, Czech MONICA and Czech post-MONICA, 1985 – 2016/17". PLOS ONE. 15 (5) e0232845. Bibcode:2020PLoSO..1532845C. doi:10.1371/journal.pone.0232845. ISSN 1932-6203. PMC 7213700. PMID 32392239.
- ^ "Cohort Profile: Estonian Biobank of the Estonian Genome Center, University of Tartu". International Journal of Epidemiology. 44: 1142.
- ^ "Commission européenne, Eurobaromètre EB64.3 - calculs SPF Économie Direction générale Statistique et Information économique". Archived from the original on 8 May 2009. Retrieved 8 January 2017.
- ^ "Non-communicable diseases risk-factor steps survey, Georgia, 2016. Executive summary" (PDF). World Health Organization.
- ^ Statistisches Bundesamt. "Körpermaße nach Altersgruppen und Geschlecht" (in German). Statistisches Bundesamt. Retrieved 5 January 2022.
- ^ "Summary of RDA for Indians - 2020, p. 7" (PDF). nin.res.in.
- ^ "Resultater fra Den nasjonale folkehelseundersøkelsen 2020" (PDF). Norwegian Institute of Public Health. p. 7.
- ^ "WHO STEPS Noncommunicable Disease Risk Factor Surveillance, Data Book For Oman" (PDF). World Health Organization. 2017. p. 65.
- ^ Non-Communicable Diseases Risk Factors Survey Pakistan. Pakistan Health Research Council 2016 (PDF). World Health Organization. 2016. p. 25. ISBN 978-969-499-008-8.
- ^ "Papua New Guinea NCD Risk Factors STEPS Report" (PDF). World Health Organization. February 2014. p. 43.
- ^ "Chronic Disease Risk Factor Surveillance: Qatar STEPS Report 2012. The Supreme Council of Health. Qatar" (PDF). World Health Organization. 2013. p. 53.
- ^ Martinchik, A N; Laikam, K E; Kozyreva, N A; Keshabyants, E E; Mikhailov, N A; Baturin, A K; Smirnova, E A (2021). "Распространение ожирения в различных социально-демографических группах населения России" [The prevalence of obesity in various socio-demographic groups of the population of Russia]. Вопросы питания. 90 (3): 67–76. doi:10.33029/0042-8833-2021-90-3-67-76. PMID 34264558. S2CID 235907158.
The body weight and height of respondents with a BMI of 18.5-24.9 kg/m2 can be considered as the average normal body weight and height of the adult population in Russia, which amounted to 70.6 kg and 175.4 cm for men, and 60.2 kg and 164 cm for women, respectively.
- ^ "Rwanda Non-communicable Diseases Risk Factors Report" (PDF). World Health Organization. 2015. p. 81.
- ^ "2008 STEPwise Approach to Chronic Disease Risk Factor Survey Report" (PDF). World Health Organization. 2008.
- ^ "WHO STEPwise Approach to NCD Surveillance, Country-Specific Standart Report, Saudi Arabia 2005" (PDF). World Health Organization. 2005. p. 40.
- ^ Maksimović, Miloš Ž; Gudelj Rakić, Jelena M.; Vlajinac, Hristina D.; Vasiljević, Nadja D.; Nikić, Marina I.; Marinković, Jelena M. (2016). "Comparison of different anthropometric measures in the adult population in Serbia as indicators of obesity: data from the National Health Survey 2013". Public Health Nutrition. 19 (12): 2246–2255. doi:10.1017/S1368980016000161. ISSN 1475-2727. PMC 10270894. PMID 26865391.
- ^ "The prevalence of the common risk factors of non-communicable diseases in Sierra Leone" (PDF). World Health Organization. 2009. p. 12, 34.
- ^ "Solomon Islands NCD Risk Factors STEPS Report" (PDF). World Health Organization. 2010. p. 43.
- ^ "시도별 성별 연령별 평균 체중 분포 현황: 일반" (in Korean). KOSIS – Korean Statistical Information Service. 23 December 2021. Retrieved 7 February 2022.
- ^ López-Sobaler, Ana M.; Aparicio, Aránzazu; Aranceta-Bartrina, Javier; Gil, Ángel; González-Gross, Marcela; Serra-Majem, Lluis; Varela-Moreiras, Gregorio; Ortega, Rosa M. (2016). "Overweight and General and Abdominal Obesity in a Representative Sample of Spanish Adults: Findings from the ANIBES Study". BioMed Research International. 2016: 1–11. doi:10.1155/2016/8341487. ISSN 2314-6133. PMC 4921130. PMID 27382572.
- ^ "Non Communicable Disease Risk Factor Survey Sri Lanka" (PDF). World Health Organization. 2015. p. 81.
- ^ "Sudan STEPwise survey for non-communicable diseases risk factors 2016 report" (PDF). World Health Organization. 2016. p. 73.
- ^ "6 kilo mer man och 4 kilo mer kvinna" (in Swedish). Archived from the original on 27 February 2014. Retrieved 27 February 2014.
- ^ "Rapport final de l'enquête STEPS Togo 2010, Togo STEPS survey report" (PDF). World Health Organization (in French). 2012. p. 61.
- ^ "Kingdom of Tonga NCD Risk Factors STEPS Report" (PDF). World Health Organization. 2014. p. 122.
- ^ "Panamerican STEPS chronic non-communicable disease risk factor survey" (PDF). World Health Organization. 2012. p. 99.
- ^ "National household health survey in Turkey prevalence of noncommunicable disease risk factors 2017" (PDF). World Health Organization. 2018. pp. 28, 78.
- ^ ""Распространненость факторов риска неинфекционных заболеваний в Туркменистане STEPS 2018"" (PDF). World Health Organization (in Russian). 2018. p. 62.
- ^ "Health Survey for England 2019 Overweight and obesity in adults and children" (PDF). Nhs.uk. 15 September 2010.
- ^ "The Welsh Health Survey 2009, p. 58" (PDF). Wales.gov.uk. 15 September 2010. Archived from the original (PDF) on 16 September 2013. Retrieved 22 January 2011.
- ^ "Social and Demographic Characteristics of Households of Ukraine" (PDF). State Statistics Service of Ukraine.
- ^ "Anthropometric Reference Data for Children and Adults: United States, 2015–2018" (PDF). Retrieved 17 February 2021.
- ^ Data extracted from "The world's fattest countries: how do you compare?". The Daily Telegraph. 21 June 2012. Archived from the original on 12 January 2022. Retrieved 22 September 2016.
External links
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Media related to Human body weight at Wikimedia Commons
Human body weight
View on GrokipediaBiological Foundations
Genetic and Heritable Factors
Twin studies and meta-analyses of heritability estimates indicate that genetic factors account for 40-70% of variation in body mass index (BMI) across populations, with a combined heritability of 0.69 (95% CI: 0.65-0.71) derived from aggregating data from multiple cohorts.[12] These estimates derive from comparisons of monozygotic and dizygotic twins, where monozygotic pairs show greater BMI concordance, attributing the excess similarity to shared genetics rather than environment.[13] Heritability appears stable or slightly higher in adulthood compared to childhood, potentially reflecting gene-environment interactions that amplify genetic predispositions over time.[14] Genome-wide association studies (GWAS) have identified over 1,000 genetic loci associated with BMI and obesity risk, underscoring the polygenic architecture of body weight regulation.[15] These loci collectively explain a portion of the observed heritability, with polygenic risk scores (PRS) derived from them predicting up to 13 kg differences in adult weight across score deciles and correlating with longitudinal weight trajectories from birth to adulthood.[16] Common variants near genes involved in hypothalamic appetite control, such as MC4R and LEPR, contribute to these effects by influencing energy intake and leptin signaling.[17] The FTO gene exemplifies a key locus, where intronic single nucleotide polymorphisms (SNPs) like rs9939609 associate with increased BMI and obesity risk through mechanisms altering mRNA demethylation and downstream gene expression in the central nervous system.[18] Carriers of the high-risk FTO allele exhibit higher caloric intake and reduced satiety, effects replicated across diverse ancestries, though the variant's impact is modulated by environmental factors like diet.[19] Rare monogenic forms, such as mutations in MC4R causing early-onset severe obesity, account for less than 5% of cases but highlight causal pathways in melanocortin signaling that GWAS variants likely influence additively.[20] Despite advances, GWAS explain only 20-30% of BMI heritability, suggesting contributions from rare variants, structural genetic elements, or epistatic interactions not fully captured in current arrays.[21] Population-specific allele frequencies further complicate PRS accuracy, with transferability lower across ancestries due to linkage disequilibrium differences.[22] These gaps emphasize that while genetics predispose to weight variation, phenotypic expression requires environmental triggers, aligning with causal models prioritizing additive genetic effects over deterministic inheritance.Evolutionary Adaptations
Human physiology exhibits adaptations favoring the accumulation and efficient utilization of body fat, shaped by natural selection in environments characterized by unpredictable food availability and high energetic demands. In ancestral hunter-gatherer settings, periodic famines and physical exertion favored individuals capable of storing excess calories as adipose tissue during periods of abundance to sustain survival and reproduction during scarcity.[23] This metabolic thrift is evident in the human capacity to deposit fat readily, with average body fat percentages of approximately 15% in adult males and 25% in females—substantially higher than the 3-5% observed in wild non-human primates like chimpanzees.[24] Adipose tissue serves multiple roles beyond energy reserves, including thermal insulation, mechanical cushioning of organs, and endocrine functions such as hormone production (e.g., leptin for appetite regulation), which likely conferred selective advantages in variable climates and against physical trauma.[23] The thrifty genotype hypothesis, proposed by geneticist James V. Neel in 1962, posits that genetic variants promoting insulin resistance and efficient nutrient storage evolved as adaptive responses to feast-famine cycles, enhancing survival in pre-agricultural human populations.[25] Under this framework, alleles that minimized energy expenditure and maximized fat deposition during caloric surplus were positively selected, as they improved famine resistance and reproductive success; for instance, populations with such traits could endure extended periods without food, a common occurrence in Paleolithic eras estimated to involve frequent seasonal shortages.[26] Empirical support includes higher obesity prevalence in populations with historical famine exposure, such as Pima Indians, where thrifty traits correlate with rapid weight gain in modern diets.[26] However, the hypothesis faces criticism for lacking direct genetic evidence of widespread positive selection for extreme thriftiness, with some models suggesting that behavioral factors, like sedentariness, amplify genotypic predispositions rather than thrift alone driving obesity epidemics.[27] Sexual dimorphism in fat distribution represents another key adaptation, with females evolving greater subcutaneous fat stores (e.g., in gluteofemoral regions) to support gestational and lactational demands, which require an estimated additional 80,000-100,000 kcal over pregnancy and weaning periods.[28] This pattern, distinct from the visceral fat preference in males (linked to androgen influence), minimizes risks to offspring viability during nutritional stress, as evidenced by cross-cultural data showing female fat reserves buffering against infant mortality in low-resource settings.[29] In males, leaner builds facilitated hunting and mobility, aligning with division-of-labor hypotheses in early hominins.[30] Evolutionary models also highlight trade-offs in adiposity levels, where moderate fatness optimized survival by balancing predation vulnerability (excess weight impairs escape) against disease risk from pathogens thriving in lean hosts during infections.[24] Simulations indicate optimal body fat around 10-20% for ancestral humans, minimizing starvation and immune suppression while avoiding obesity-related mobility costs; deviations in modern contexts, with sedentary lifestyles and caloric density, disrupt this equilibrium.[24] Brown adipose tissue, which generates heat via uncoupled respiration, further adapted humans to cold exposure post-migration from Africa around 60,000-100,000 years ago, aiding thermoregulation without shivering.[30] These traits underscore a genome calibrated for scarcity, rendering contemporary abundance a mismatch that elevates obesity risk without negating the adaptive value in original selective pressures.[25]Physiological Regulation
The physiological regulation of human body weight primarily occurs through homeostatic mechanisms that maintain energy balance by integrating peripheral signals about nutrient availability and adipose stores with central neural circuits to modulate food intake and energy expenditure. The hypothalamus serves as the central integrator, with nuclei such as the arcuate nucleus (ARC) containing neurons that respond to circulating hormones and metabolites to orchestrate autonomic, endocrine, and behavioral responses.[31][32] Key orexigenic (appetite-stimulating) pathways involve neuropeptide Y (NPY) and agouti-related peptide (AgRP) neurons that promote feeding and reduce thermogenesis, while anorexigenic (appetite-suppressing) pathways feature pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) neurons that inhibit intake and enhance energy use.[31] Adipose tissue-derived signals, particularly leptin, act as primary indicators of long-term energy stores, with plasma levels correlating directly with fat mass to signal satiety via hypothalamic receptors, thereby suppressing appetite and increasing expenditure.[33] Insulin, secreted postprandially from pancreatic beta cells, similarly functions as an adiposity signal, crossing the blood-brain barrier to inhibit hypothalamic NPY/AgRP neurons and promote satiety, with chronic elevations reflecting sustained energy surplus.[34] In contrast, ghrelin, produced predominantly by the stomach during fasting, rises preprandially to activate NPY/AgRP pathways, stimulating hunger and growth hormone release to mobilize energy reserves.[35] These hormones interact dynamically; for instance, leptin exerts inhibitory effects on ghrelin secretion, and disruptions in this balance, such as leptin resistance in obesity, impair effective regulation.[36] Experimental evidence from rodent models and human studies supports a defended body weight range, where deviations trigger compensatory adaptations: weight loss below this range reduces leptin and insulin while elevating ghrelin, lowering resting metabolic rate by up to 15-20% and increasing hunger drive, often leading to regain.[37] Conversely, overfeeding expands fat mass, enhancing leptin signaling to curb intake until equilibrium restores.[38] Gut-derived peptides like cholecystokinin (CCK) and peptide YY (PYY) provide short-term satiety signals post-meal, reinforcing hypothalamic control without overriding long-term adiposity defenses.[32] This system prioritizes fat storage efficiency, reflecting evolutionary pressures for survival amid scarcity, though modern abundance challenges its efficacy in preventing excess accumulation.[39]Measurement Methods
Body Mass Index and Limitations
Body mass index (BMI) is calculated as an individual's body weight in kilograms divided by the square of their height in meters (kg/m²).[40] Developed in the 19th century by Adolphe Quetelet as a population-level statistic, it serves as a screening tool to categorize adults into weight classes: underweight (BMI < 18.5), normal weight (18.5–24.9), overweight (25.0–29.9), and obese (≥30.0), with obesity subdivided into classes I (30.0–34.9), II (35.0–39.9), and III (≥40.0).[41] [42] These thresholds, adopted by organizations like the World Health Organization in 1998 and refined by the CDC, correlate with increased risks of conditions such as type 2 diabetes, cardiovascular disease, and mortality at the population level, where higher BMI values predict adverse outcomes in large cohorts.[43] [42] Despite its simplicity and low cost, BMI's utility diminishes for individual assessment because it proxies total body mass rather than adiposity, failing to differentiate fat from lean tissue like muscle or bone.[44] Peer-reviewed analyses indicate that BMI misclassifies at least 50% of U.S. adults with excess body fat as normal weight or merely overweight, particularly underestimating obesity in those with low muscle mass (e.g., elderly or sarcopenic individuals) and overestimating it in muscular populations like athletes.[45] It also overlooks fat distribution, such as visceral adipose tissue—which drives metabolic risks more than subcutaneous fat—and ethnic variations, where Asians face higher cardiometabolic risks at lower BMI thresholds (e.g., ≥23 for overweight per some studies) compared to Europeans.[46] [44] At the individual level, BMI's predictive accuracy for health outcomes is limited, as evidenced by longitudinal data showing weak correlations with future morbidity when body composition is directly measured via dual-energy X-ray absorptiometry (DXA) or MRI; for instance, "fit but fat" phenotypes exhibit lower risks despite elevated BMI, while "thin outside, fat inside" (TOFI) cases with normal BMI but high visceral fat incur elevated dangers.[47] [48] The American Medical Association recognized these shortcomings in 2023, advising against sole reliance on BMI for clinical decisions due to its insensitivity to factors like age, sex, and socioeconomic influences on body composition.[48] While effective for epidemiological tracking—where it tracks trends like the U.S. obesity prevalence rising from 30% in 2000 to over 42% by 2020—BMI alone overlooks causal drivers of weight-related pathology, prompting calls for adjunct metrics in precision medicine.[47] [42]Alternative Assessment Tools
Waist circumference measures abdominal fat accumulation, a stronger predictor of cardiometabolic risks than BMI alone, as it correlates with visceral adiposity independently of overall body mass.[49] Thresholds for elevated risk include greater than 102 cm in men and 88 cm in women, according to harmonized guidelines from obesity societies.[50] Combining waist circumference with BMI enhances identification of high-risk obesity phenotypes, outperforming either metric in isolation for forecasting conditions like hypertension and diabetes.[49] [51] Waist-to-hip ratio assesses fat distribution by dividing waist measurement by hip circumference, revealing android (central) versus gynoid (peripheral) patterns, with higher ratios linked to elevated mortality and disease risks.[52] Values exceeding 0.90 in men and 0.85 in women indicate increased cardiovascular and all-cause mortality hazards, surpassing BMI's predictive power in large cohort studies.[53] [54] For instance, a 2023 analysis of over 500,000 participants found waist-to-hip ratio more consistently associated with death from any cause than BMI or absolute fat mass.[52] Direct body composition assessments quantify fat mass versus lean mass, circumventing BMI's inability to differentiate these components. Dual-energy X-ray absorptiometry (DEXA) serves as a reference standard, offering precision within 1-2% for total body fat percentage through low-dose X-ray scanning of bone, fat, and lean tissue.[55] Hydrostatic weighing, based on Archimedes' principle, determines body density via underwater weighing and estimates fat percentage with errors under 2%, though it requires participant submersion and assumes constant hydration.[56] Air-displacement plethysmography (e.g., Bod Pod) measures volume in a sealed chamber, yielding comparable accuracy to hydrostatic methods but with greater accessibility.[57] Field methods provide practical alternatives for clinical or population use. Skinfold calipers measure subcutaneous fat at sites like triceps and abdomen, predicting total body fat with a margin of error around 3% when calibrated against reference techniques.[58] Bioelectrical impedance analysis (BIA) estimates fat via electrical conductivity differences between fat and lean tissue, correlating moderately with DEXA (r=0.8-0.9) but prone to variability from hydration status and device quality.[59] Multifrequency BIA improves reliability in obese populations, serving as a viable proxy for DEXA in resource-limited settings.[60] Advanced imaging like magnetic resonance imaging (MRI) or computed tomography (CT) precisely quantifies visceral fat volume, critical for metabolic syndrome assessment, though cost and radiation (for CT) limit routine application.[61] Emerging anthropometric formulas, such as relative fat mass (RFM) derived from height and waist, offer BMI-like simplicity with improved fat estimation accuracy in validation studies against DEXA.[62] The Devine formula provides a height-based estimate of ideal body weight in adults, commonly used in medical contexts for dosing weight-based medications. For men, it is calculated as 50 kg plus 2.3 kg for each inch over 5 feet, yielding a single-point estimate unlike BMI ranges.[63] These tools collectively enable nuanced evaluation of adiposity, prioritizing fat quality and location over mass index for health risk stratification.[64]Estimation in Children and Special Cases
In pediatric emergencies, accurate body weight estimation is critical for dosing medications and selecting equipment, as direct measurement may be infeasible. The Broselow tape, a color-coded length-based tool calibrated for children up to approximately 36 kg, correlates recumbent length with pre-established weight zones derived from U.S. population data.[65] It achieves acceptable accuracy, with about 54% of estimates within 10% of actual weight (PW10) across studies, outperforming age-based methods in non-obese children under 25 kg, though precision declines in heavier or obese individuals due to outdated normative data. [66] Alternatives like the PAWPER XL tape, which incorporates mid-upper arm circumference (MUAC) alongside length, yield higher accuracy, often exceeding 80% PW10, particularly in diverse or malnourished populations where Broselow underperforms.[67] Age-based formulas, such as the Advanced Pediatric Life Support (APLS) equation—weight (kg) = (age in years × 2) + 8—provide simplicity but systematically underestimate weights in contemporary children due to rising obesity rates, with errors increasing beyond age 10.[68] Updated formulas, like those for ages 1-5 years: weight (kg) = 2 × (age + 5), better align with current growth trends in developed countries.[69] For special cases, such as children with medical complexity or obesity, length- and MUAC-adjusted methods like PAWPER XL maintain superiority, with Broselow achieving only 47.7% PW10 in complex cases.[70] In amputees, estimating pre-amputation weight involves adding proportional limb mass—e.g., using WtE = Wto / (1 - P), where WtE is estimated total weight, Wto is observed weight, and P is the fractional body weight of the amputated segment (typically 0.05-0.16 for lower limbs)—to avoid underestimating nutritional needs or BMI.[71] This adjustment is essential, as standard scales reflect post-amputation mass, potentially skewing metabolic assessments.[72] In elderly or immobile patients, similar proportional corrections apply, though data are sparser, emphasizing the need for validated tools over unadjusted measures.[73]Determinants of Weight Variation
Innate Biological Influences
Innate biological influences on human body weight encompass physiological mechanisms such as hormonal signaling, neural pathways in the hypothalamus, and metabolic processes that establish baseline energy homeostasis from early development. These factors operate through feedback loops that defend against deviations in adiposity, often independent of voluntary behavior or external inputs.[20] Disruptions in these systems, including resistance to satiety signals, can predispose individuals to weight gain or retention.[2] Central to this regulation is the leptin-melanocortin pathway, where leptin, secreted by adipocytes in proportion to fat mass, binds hypothalamic receptors to suppress appetite and increase energy expenditure via pro-opiomelanocortin (POMC) neurons and melanocortin-4 receptors (MC4R).[20] Deficiency in leptin leads to severe hyperphagia and obesity, as observed in rare congenital cases, while common variants impair signaling efficiency.[20] Antagonistic hormones like ghrelin, produced by gastric cells, stimulate hunger and oppose leptin's effects, with elevated levels correlating to higher body weight in observational data.[74] Thyroid hormones further modulate basal metabolism, influencing overall energy use.[2] Resting metabolic rate (RMR), comprising 60-75% of daily energy expenditure, varies innately and predicts future weight gain; individuals with lower RMR independent of body composition are at higher risk.[2] This rate declines with age from the fourth decade onward, contributing to midlife weight accumulation even without caloric surplus.[2] Non-exercise activity thermogenesis, such as fidgeting, adds variability but stems from innate neural drives rather than learned habits.[2] Prenatal conditions program these innate trajectories; maternal pre-pregnancy obesity elevates offspring adiposity risk by 1.8 kg/m² BMI per standard deviation increase in maternal BMI, mediated by epigenetic alterations like DNA methylation in metabolic genes (e.g., PPARGC1A) and hypothalamic rewiring.[75] Excessive early gestational weight gain amplifies this, with cohort studies showing persistent effects into adulthood via altered fetal nutrient exposure and placental function.[75] Sex-specific innate differences also arise, with males exhibiting higher RMR due to greater lean mass and females showing enhanced fat deposition influenced by estrogen-mediated pathways.[2][76]Behavioral and Dietary Inputs
Dietary caloric intake serves as the primary driver of energy surplus or deficit, with sustained excess intake relative to expenditure causing adipose tissue accumulation and weight gain, as evidenced by controlled feeding studies demonstrating predictable body mass changes proportional to net energy imbalance.[77] [78] Macronutrient composition modulates intake indirectly; for instance, higher dietary protein intake enhances satiety and preserves lean mass during energy restriction, facilitating greater fat loss compared to lower-protein diets in randomized trials.[79] Energy-dense foods, such as those high in refined sugars and fats, promote overconsumption by reducing satiety signals per calorie ingested, correlating with longitudinal weight gain in cohort studies tracking over 120,000 adults where each daily serving increase in sugary beverages or potatoes added 0.4–1.0 pounds over four years.[80] [81] Conversely, diets emphasizing whole foods like vegetables, whole grains, and nuts show inverse associations, with meta-analyses of observational data linking higher consumption to lower obesity risk through reduced overall caloric intake.[82] Behavioral patterns amplify dietary effects via habitual choices affecting total energy flux. Sedentary lifestyles diminish non-exercise activity thermogenesis and basal expenditure adjustments, contributing to weight gain; meta-analyses of intervention trials indicate that replacing sedentary time with moderate activity yields modest reductions in body weight (approximately 1–2 kg over 6–12 months) independent of diet.[83] [84] Physical activity interventions, particularly those increasing moderate-to-vigorous bouts, elevate total daily expenditure by 200–500 kcal, supporting weight loss when paired with caloric control, though compensatory increases in intake can attenuate effects in some individuals.[85] Eating behaviors, including portion distortion and frequent snacking, exacerbate intake; experimental evidence shows larger portions increase consumption by 20–30% without compensatory hunger reduction, driving positive energy balance in free-living settings.[80]- Meal timing and frequency: Irregular patterns, such as skipping breakfast, associate with higher BMI in prospective studies, potentially via disrupted appetite regulation and increased evening overeating.[32]
- Mindful eating practices: Interventions promoting awareness reduce impulsive intake, yielding 0.5–1.5 kg greater weight loss in meta-analyses of behavioral programs.[86]
- Stress and sleep: Chronic stress elevates cortisol-driven intake of palatable foods, while sleep restriction (<6 hours/night) impairs leptin signaling and boosts ghrelin, increasing caloric consumption by 300–500 kcal daily in controlled trials, independent of activity levels.[87][32]
Environmental and Societal Pressures
The modern food environment, characterized by widespread availability of energy-dense, nutrient-poor foods, contributes significantly to elevated body weights. Between 1977 and 1996, portion sizes for items such as salty snacks, soft drinks, and french fries increased substantially both at home and in restaurants, paralleling a rise in average daily caloric intake from approximately 2,160 calories in 1970 to 2,673 calories by the early 2000s.[89][90] This expansion in serving sizes has been linked to higher energy consumption, as larger portions often lead to passive overeating without corresponding adjustments in appetite regulation.[91] Aggressive marketing of unhealthy foods exacerbates these trends, particularly among children. In the United States, about 75% of foods advertised to youth are high in sugar, fat, or salt, with exposure influencing preferences, purchase requests, and consumption patterns that contribute to obesity risk.[92] Systematic reviews confirm that such advertising drives increased intake of processed snacks and beverages, undermining dietary guidelines and correlating with population-level weight gain.[93][94] Urban design and infrastructure also impose pressures favoring sedentariness. Urban sprawl, marked by low-density development and automobile dependency, reduces opportunities for walking and active transport, associating with higher obesity prevalence through decreased physical activity.[95] Studies across U.S. metropolitan areas show that higher sprawl indices correlate with elevated body mass index (BMI) and diabetes rates, mediated by less active commuting and leisure-time exercise.[96][97] Conversely, walkable neighborhoods with mixed-use zoning exhibit inverse associations with adiposity.[98] Socioeconomic gradients further shape weight outcomes, with lower status often tied to obesogenic exposures. In high-income nations, inverse relationships predominate: adults in the lowest income or education quartiles face 1.5-2 times higher obesity odds, attributable to limited access to healthy foods, higher stress, and environments prioritizing convenience over nutrition.[99][100] Food deserts—areas with poor fresh produce availability—amplify this in low-income tracts, linking to BMI elevations independent of individual behaviors.[101] These patterns reflect systemic incentives for calorie surplus in resource-constrained settings, rather than personal failings alone.[102]Weight Dynamics
Short-Term Fluctuations
Human body weight commonly fluctuates by 1 to 2 kilograms (2.2 to 4.4 pounds) over the course of a few days, driven primarily by transient changes in fluid volume, gastrointestinal contents, and non-adipose tissue rather than alterations in fat mass.[103] These variations occur diurnally and weekly, with weights often higher in the morning after overnight fluid retention and lower after daily excretions, and exhibiting patterns such as elevated readings on weekends due to altered eating and activity habits.[104] Such shifts are physiological norms, reflecting the body's dynamic balance of intake, metabolism, and elimination rather than indicators of net energy surplus or deficit.[105] Dietary factors prominently influence these changes, as undigested food and beverages in the digestive tract can add temporary mass, while high sodium intake triggers extracellular fluid retention via osmotic mechanisms to maintain electrolyte balance.[106] Carbohydrate consumption exacerbates this through glycogen synthesis in liver and muscle, where each gram of stored glycogen associates with 3 to 4 grams of water, potentially accounting for rapid 1 to 2 kilogram gains or losses during shifts in carb intake.[107] Conversely, depletion of glycogen stores, as in low-carbohydrate dieting or fasting, releases bound water, yielding quick but non-fat reductions often misinterpreted as fat loss.[108] Hormonal influences contribute variably, particularly in females, where premenstrual progesterone and estrogen fluctuations promote sodium conservation and fluid retention, yielding an average 0.5 kilogram increase peaking around menstruation due to extracellular edema.[109] Physical exertion induces short-term dehydration from sweat loss, offset potentially by post-exercise inflammatory responses that retain fluid, while medications like corticosteroids or conditions such as infections can amplify retention through renal or vascular effects.[110] To discern true body composition trends from these artifacts, consistent measurement protocols—such as morning weigh-ins post-voiding and fasting—are recommended, as single readings obscure underlying stability in adipose and lean mass.[111]Long-Term Homeostasis and Set Points
The human body maintains long-term weight stability through homeostatic mechanisms that integrate neural, hormonal, and metabolic signals to defend a characteristic range of adiposity, often termed the "set point." This regulation operates over months to years, contrasting with short-term fluctuations driven by daily energy imbalances, and involves active resistance to deviations via adjustments in resting metabolic rate (RMR), physical activity, and appetite. Empirical evidence from longitudinal studies indicates that adult body weight remains relatively constant without intentional intervention, with annual changes typically under 1-2 kg in non-obese individuals, reflecting a biological defense against perturbations.[112][113] Central to this process is the hypothalamus, which coordinates signals from adipose tissue—primarily leptin, which circulates in proportion to fat mass—to modulate energy expenditure and intake. In states below the set point, such as after caloric restriction, the body induces adaptive thermogenesis, suppressing RMR beyond what is predictable from loss of fat-free mass alone, often by 10-15% or more. This metabolic adaptation, observed in controlled trials like the Minnesota Starvation Experiment (1944-1945) and modern interventions such as The Biggest Loser cohort (followed up to 6 years post-competition), persists long-term and correlates with increased hunger hormones like ghrelin, promoting weight regain to restore the defended level.[114][37][115] The set point is influenced by genetic factors, accounting for 40-70% of variance in adult BMI, with polygenic scores predicting defended weights across populations. Environmental exposures, particularly during developmental windows like infancy or adolescence, can upwardly reset the set point, as evidenced by twin studies showing higher concordance in monozygotic pairs for obesity trajectories. However, deliberate downward shifts are challenging; sustained low-energy states may eventually recalibrate the set point lower, but relapse rates exceed 80% within 5 years for most dieters due to counter-regulatory responses.[116][117][113] Critics of a rigid set point propose a "settling point" model, where weight stabilizes at the intersection of intake drives and expenditure constraints without precise defense, but physiological data—such as disproportionate RMR suppression post-weight loss—support active homeostatic control, albeit imperfect in modern high-calorie environments. This framework explains the obesity epidemic's persistence despite interventions: while external factors elevate set points population-wide, individual biology enforces reversion unless overridden by pharmacological or surgical means that mimic satiety signals.[112][118][119]Health Consequences
Adverse Effects of Excess Adiposity
Excess adiposity, particularly visceral fat accumulation, promotes chronic systemic inflammation, insulin resistance, endothelial dysfunction, and dysregulated adipokine signaling, which drive multiple disease pathways.[120] [121] A dose-response meta-analysis of individual participant data from 239 prospective studies involving 3.9 million adults demonstrated that body-mass index (BMI) levels exceeding 25 kg/m² are linked to elevated all-cause mortality, with hazard ratios rising linearly; for instance, BMI 30.0–34.9 kg/m² carried a hazard ratio of 1.18 (95% CI 1.12–1.25) compared to BMI 22.5–25.0 kg/m², while BMI ≥35.0 kg/m² yielded 1.45 (1.41–1.48).30175-1/fulltext) Central adiposity indices, such as waist-to-hip ratio or visceral adiposity index, exhibit even stronger mortality associations than BMI, independent of overall body size.[120] [122] In the cardiovascular domain, excess adiposity causally elevates risks for hypertension, coronary heart disease, heart failure, and stroke through mechanisms including atherogenic dyslipidemia, sympathetic overactivity, and prothrombotic states.[123] [124] Observational data indicate that obesity (BMI ≥30 kg/m²) confers a 1.5- to 2-fold increased risk of cardiovascular events, with visceral fat specifically amplifying this via proinflammatory cytokine release and hepatic fat deposition.[123] [124] For type 2 diabetes, excess adiposity induces peripheral insulin resistance and beta-cell dysfunction, with meta-analyses showing relative risks escalating to 7-fold or higher in individuals with severe obesity compared to normal weight.[125] Dyslipidemia, characterized by elevated triglycerides and reduced HDL cholesterol, further compounds metabolic derangements, attributable to adipose tissue lipotoxicity.[125] Excess adiposity heightens malignancy risk for at least 13 cancer types, including colorectal, postmenopausal breast, endometrial, esophageal, and renal cell carcinomas, via hyperinsulinemia, elevated estrogen from aromatization in fat tissue, and chronic inflammation fostering carcinogenesis.[126] Relative risks range from 1.2- to 3.5-fold depending on cancer site and adiposity measure, with Mendelian randomization studies supporting causality independent of confounding factors like smoking.[126] [127] Nonalcoholic fatty liver disease progresses to steatohepatitis and cirrhosis in up to 20-30% of obese individuals, driven by ectopic fat overflow and oxidative stress.[123] Musculoskeletal burdens include osteoarthritis, where each kilogram of excess weight imposes 4-fold joint loading during locomotion, accelerating cartilage degradation; respiratory complications encompass obstructive sleep apnea from pharyngeal fat deposition and reduced lung compliance.[5] [5] Overall, these effects contribute to a 5- to 10-year reduction in life expectancy for individuals with class III obesity (BMI ≥40 kg/m²), with U.S. estimates attributing 111,000–300,000 annual excess deaths to obesity-related causes after adjusting for confounders.[128] [129]Risks of Underweight Conditions
Being underweight, defined as a body mass index (BMI) below 18.5 kg/m² in adults, is associated with elevated all-cause mortality risk, with meta-analyses indicating a hazard ratio of approximately 1.2 to 1.4 compared to normal BMI ranges, though this may partly reflect confounding from underlying illnesses or smoking.[130][131] Systematic reviews confirm a U-shaped relationship between BMI and mortality, where underweight status correlates with higher rates of death from cardiovascular, respiratory, and infectious causes, independent of some confounders in adjusted models.[132]30288-2/fulltext) Low body weight impairs immune function, increasing susceptibility to infections; cohort studies link underweight BMI to higher hospitalization rates for pneumonia and other respiratory infections, as reduced fat and muscle reserves limit energy availability for immune responses.[133][134] This vulnerability extends to surgical outcomes, with underweight patients experiencing prolonged recovery, higher complication rates, and increased postoperative mortality due to diminished physiological reserves.[135] Skeletal health suffers in underweight individuals, with accelerated bone loss leading to osteoporosis; longitudinal data show underweight adults have lower bone mineral density and a 2-3 times higher fracture risk, particularly in postmenopausal women, as caloric restriction suppresses osteoblast activity and estrogen production.[136][137] Micronutrient deficiencies common in underweight states exacerbate this, contributing to impaired collagen synthesis and mineralization.[138] Reproductive risks are pronounced, especially in women, where underweight BMI disrupts menstrual cycles, causing amenorrhea and infertility through hypothalamic suppression of gonadotropins; studies report odds ratios up to 3.5 for ovulatory dysfunction in those with BMI under 18.5.[139][136] In men, low weight correlates with reduced testosterone and sperm quality, though evidence is sparser. Pregnancy complications, including low birth weight and preterm delivery, rise with maternal underweight, per epidemiological analyses.[134] In older adults, underweight status heightens frailty, sarcopenia, and mortality from falls or acute events, with BMI below 18.5 linked to 20-50% higher death rates in geriatric cohorts after adjusting for comorbidities.05024-4/fulltext) Overall, these risks stem from inadequate energy stores impairing organ function and repair, underscoring underweight as a maladaptive state rather than benign leanness in most contexts.[135]Evidence-Based Healthy Ranges
The relationship between body mass index (BMI), calculated as weight in kilograms divided by height in meters squared, and health outcomes exhibits a U-shaped curve in numerous cohort studies and meta-analyses, with elevated all-cause mortality risks at both low and high extremes. Conventional classifications define BMI under 18.5 kg/m² as underweight, 18.5–24.9 kg/m² as normal, 25.0–29.9 kg/m² as overweight, and 30.0 kg/m² or higher as obese; however, empirical data on longevity often indicate the nadir of mortality risk extends into or centers within the overweight range, particularly after excluding smokers and early adulthood deaths to mitigate reverse causation.[132][130] A 2024 meta-analysis of over 2 million adults across multiple studies identified the lowest all-cause mortality in the BMI range of 25.0–30.0 kg/m², with hazard ratios rising below 20.0 kg/m² (HR 1.28) and above 35.0 kg/m² (HR up to 1.92).[130] Similarly, a 2023 analysis of U.S. National Health Interview Survey data (n=142,569) found no significant mortality increase from BMI 22.5–34.9 kg/m² in adults aged 65 and older, with adjusted hazard ratios near 1.0 compared to the reference 22.5–24.9 kg/m², while underweight BMI below 18.5 kg/m² conferred a 1.5-fold risk elevation.[140] In sex-stratified data from a 2023 UK Biobank study, men exhibited minimal cardiovascular and all-cause mortality at BMI 25.0–29.9 kg/m² (HR 0.92 vs. 21.0–24.9 kg/m²), whereas women showed slightly lower risks at 22.5–24.9 kg/m², though differences attenuated after adjusting for comorbidities.[141] Age-specific optima further broaden these ranges, as metabolic reserve and sarcopenia influence outcomes; a 2015 Korean cohort study (n=1,213,829) reported optimal BMI rising from 23.0–25.9 kg/m² in men aged 18–34 to 25.0–28.9 kg/m² in those 65–74, with parallel shifts in women (e.g., 21.0–23.9 kg/m² to 24.0–26.9 kg/m²), reflecting lower underweight risks in older populations.[142] For never-smokers, a 2016 dose-response meta-analysis (n=3.9 million) pinpointed the mortality nadir at BMI 23.0–24.0 kg/m², with overweight BMI 25.0–29.9 kg/m² yielding HR 1.06 (95% CI 1.02–1.11), a modest elevation compared to obese classes where risks doubled or more.[132] Beyond BMI, direct measures of adiposity provide nuanced evidence; a 2025 study of young adults (n=2,561) found body fat percentage superior to BMI for predicting 15-year mortality, with optimal ranges around 18–25% for men and 25–32% for women correlating to lower cardiovascular events, independent of lean mass. Waist-to-height ratio below 0.5 has also been linked to reduced cardiometabolic risks across BMI categories in systematic reviews, highlighting BMI's limitations in distinguishing visceral fat from muscle. Underweight conditions (BMI <18.5 kg/m²) consistently predict higher frailty-related mortality (HR 1.2–1.8), especially in non-elderly cohorts, while grade 1 obesity (30.0–34.9 kg/m²) shows neutral or protective effects in chronic disease contexts like heart failure, termed the "obesity paradox."[143]30175-1/fulltext)Global Patterns and Trends
Regional and National Averages
Average body weights and body mass indices (BMI) exhibit substantial variation across regions and nations, reflecting differences in genetics, nutrition, physical activity, socioeconomic factors, and cultural practices. Globally, the mean BMI for adults reached approximately 25 kg/m² for both men and women by 2016, marking the threshold for overweight status, with higher values predominant in high-income regions and lower values in parts of Asia and Africa. While central and eastern Africa exhibit low mean BMIs (e.g., 21.4 kg/m² for men in central Africa), North African countries like Egypt show higher averages, with average male height of 173 cm and weight of 83.1 kg corresponding to a BMI of 27.8; no direct data exists for the average weight of men exactly 5'4" (162.6 cm) tall in Cairo or globally, but estimates based on population BMI approximate ~73 kg (161 lbs) in Egypt and ~65 kg (143 lbs) globally (at average male BMI ~24.5), with variations by age, region, and study.[144] Regional disparities are pronounced; in 2014, mean BMI for men ranged from 21.4 kg/m² in central Africa and south Asia to 29.2 kg/m² in Polynesia and Micronesia, while for women it varied from 21.8 kg/m² in south Asia and eastern Africa to 34.0 kg/m² in Polynesia and Micronesia.30054-X/fulltext) These patterns persist into recent years, with absolute body weights in North America averaging 80.7 kg per adult in estimates from 2012, the highest among continents.[145] In high-obesity nations such as those in Oceania, mean BMIs exceed 32 kg/m²; for instance, the Cook Islands recorded an average BMI of 32.9, followed closely by Nauru at 32.5.[146] These elevated averages correlate with obesity prevalence rates surpassing 60% in adults. Conversely, East Asian countries maintain among the lowest figures; in Japan, average adult male weight stands at 62.5 kg and female at 52.9 kg, corresponding to BMIs typically below 24 kg/m².[147] In the United States, national surveys report higher averages: men at 90.4 kg (199 pounds) and women at 77.5 kg (170.9 pounds), based on measured data from adults aged 20 and over.[3]| Region/Nation | Mean Adult BMI (kg/m², approximate recent) | Average Weight Examples (kg) | Source Notes |
|---|---|---|---|
| Polynesia/Micronesia | Men: 29.2; Women: 34.0 (2014) | N/A | Regional high; small island nations like Nauru exceed 32 overall.30054-X/fulltext)[146] |
| North America (US) | ~28 (inferred from prevalence) | Men: 90.4; Women: 77.5 | NHANES measured weights.[3] |
| East Asia (Japan) | ~23 | Men: 62.5; Women: 52.9 | National sports agency data.[147] |
| South Asia/Central Africa | Men: 21.4; Women: 21.8 (2014) | ~50-60 (males) | Lowest regional means; underweight common.30054-X/fulltext) |
