eTable 1. Characteristics of the included studies.
| Study | Study participants | Index test | Reference test | |||||
| Reference | Country/ period | Study population included in analysis | Number n (% women) | Age (years) Mean ± SD Median (range) | Method | Question | Answer options | BMI categories (% per category) |
| Agrawal 2014 (e10) |
India 2003 |
Ever-married women, except pregnant women, women in childbed & underweight women | 322 (100) |
38.4 (20–54) |
Interview | “I feel I am…” | “Less than normal weight”, “normal weight”, “more than normal weight” | NW/OW/O (39.1/37.3/ 23.6) |
| Akgöz 2017 (e8) |
Turkey 2015 |
Women from 2 health centers with high and low SES | 300 (100) |
57.2 ± 4.8 (50–65) |
Interview with record sheets | “In your opinion, which of the following refers to your body:” | “Thin”, “normal”, “overweight”, “fat”, “extremely fat” | UW/NW/OW/O (0.7/15.7/28.7/55.0) |
| Akindele 2017 (e11) | Nigeria 2012– 2013 |
Overweight and obese adults | 567 (66.0) |
n.s. | Questionnaires | “How do you describe your body weight?” | “Underweight”, “normal weight”, “a little overweight”, “very overweight” | OW/O (54.1/45.9) |
| Akinpelu 2015 (e12) | Nigeria 2006 |
Rural residents | 183 (48.6) |
40.2 ± 13.0(18–71) | Interview | “Which of the following terms/words best describe the way you perceive your body size?” | “Underweight”, “normal weight”, “overweight”, “obese”, “morbidly obese” | UW/NW/OW/O (3.8/61.2/29.0/6.0) |
| Barichella 2011 (e13) | Italy 2008 |
Adults attending the ‘Obesity Day’ initiative | 914 (66.2) |
51.1 ± 14.2 | Questionnaires | n.s. | “Normal weight”, “overweight”, “mildly obese”, “moderately/severely obese” | UW+NW/OW/O (27.9/34.8/37.3) |
| Barzuca 2013 (e9) | Romania, n.s. | Untrained students (n = 78), athletes (n = 17), patients on dialysis (n = 15) | 110 (50.9) |
26.0 ± 13.0(19–72) | Questionnaires | “How do you perceive your weight?” | “Under normal value”, “around normal value”, “above normal value” | UW/NW/OW+O (8.2/60.9/30.9) |
| Baur 2012 (e6) |
USA, n.s. | Firefighters from the Midwest | 768 (0) |
37.6 ± 8.5 | Questionnaires | “I think my body weight is…” | “Underweight (skinny)”, “healthy/normal or muscular”, “overweight”, “obese (fat)” | NW/OW/O (12.4/50.9/36.7) |
| Blokstra 1999 (23) |
Netherlands 1995 |
Participants in an observational program (MORGEN project), except pregnant women, diabetics, and cancer patients | 4601 (53.2) |
(20–65) | Questionnaires | “How would you describe your current weight?” | “Too big”, “too little”, “just right” | NW/OW/O (54.3/35.4/10.3) |
| Caleychetty 2016 (e14) |
Mauritius 2009 |
Representative cross-section, except pregnant women | 5736 (52.7) |
46 (20–74) | Questionnaires | “Do you think your current weight is …” | “Too low”, “about right”, “a little too high”, “much too high” | UW/NW/OW/O (5.2/44.1/34.5/16.2) |
| Colchero 2014 (14) |
Mexico 2006 |
Representative cross-section, except pregnant women | 32 052 (60.0) |
43.3 ± 0 (> 20) | Questionnaires | n.s. | “Low weight”, “normal weight”, “overweight”, “obese” | UW/NW/OW/O (0.8/28.2/39.9/31.1) |
| DeVille-Almond 2011 (e1) |
United Kingdom 2007 |
Male drivers at motorway service stations | 263* (0) |
52 (42–60) | Questionnaires | “How would you describe yourself?” | “Thin”, “just right”, “overweight”, “obese” | NW/OW/O (19.4/46.0/34.6) |
| Dorosty 2014 (e15) |
Iran 2010 |
Female staff of an urban health center, except pregnant, nursing, or underweight women | 542 (100) |
37.3 ± 8.9 | Questionnaires | “Do you imagine yourself as…” | “Underweight”, “normal weight”, “overweight”, “obese” | NW/OW/O (53.5/31.4/15.1) |
| Drumond 2012 (e16) |
Mexico 2009 |
College applicants | 3622 (52.1) |
(18–20) | n.s. | n.s. | “Severely underweight/underweight”, “normal”, “overweight”, “obese” | UW/NW/OW/O (7.4/62.0/21.0/9.6) |
| Duncan 2014 (e17) |
South Africa 2012 |
Hypertensive patients in a rural health center | 466 (n.s.) |
58 ± 13.8 (23–98) | Questionnaires | “Do you personally think that you are … ?” | “Underweight”, “normal weight”, “overweight”, “I don’t know” | UW/NW/OW/O (3.9/33.9/26.8/35.4) |
| El-Kassas 2016 (e4) |
Lebanon 2015 |
Health science students without physical impairment, chronic metabolic disease, or drug use | 369 (86.4) |
19.6 ± 1.7 (18– 25) | Structured interview with record sheets | n.s. | “Underweight”, “normal”, “overweight”, “obese” | UW/NW/OW/O (4.3/63.4/27.6/4.6) |
| Faber 2005 (e18) |
South Africa, n.s. | Women of a rural South African village | 187 (100) |
33.5 ± 8.9 (25–55) | Interview | n.s. | “Too thin”, “about right”, “too fat” | NW/OW/O (28.9/41.2/29.9) |
| Gao 2017 (e19) |
China 2012 |
Overweight and obese persons in a northeastern province of China | 10 177* (51.6) |
(18–79) | Questionnaires | n.s. | “Very thin”, “normal weight”, “overweight”, “too fat” | OW/O (70.2/29.8) |
| Griger 2015 (16) |
Germany 2008 –2011 |
Representative cross-section | 6886 (52.2) |
(18–79) | Questionnaires | “Do you think you are…?” | “Much too thin”, “a little bit too thin”, “about the right weight”, “a little bit too fat”, “much too fat” | UW/NW/OW/O (1.3/37.1/37.8/23.9) |
| Harris 2016 (e20) |
USA 2004 –2006 |
Low-income, obese African American women, except pregnant women and women with diseases/medications with an effect on weight | 118 (100) |
41.7 ± 14.4 | Questionnaires | “I feel I am …” | “Underweight”, “normal weight”, “overweight”, “obese” | O (100) |
| Hendley 2011 (e21) |
USA, n.s. | Black and white city dwellers in Atlanta | 429* (67.4) |
50.4 ± 9.4 (30–66) | Telephone interview | “How would you describe your weight? Would you say…” | “Underweight”, “about right”, “overweight”, “obese” | UW + NW/OW/O (27.2/32.1/ 40.7) |
| Herbert 2017 (e22) |
Australia 2011 –2012 | Representative cross-section, except pregnant women | 7947* (52.4) |
49 ± 17.6 | Personal interview | n.s. | “Acceptable weight”, “underweight”, “overweight” | UW/NG/ OW/O (1.5/34.4/36.4/27.7) |
| Howard 2008 (e23) |
Australia 2004 –2007 | Residents of an Australian city | 2382 (50.0) | n.s. | Computer-assisted telephone interview | “In terms of your weight, do you consider yourself to be …” | “Too thin”, “a little thin”, “normal weight”, “a little overweight”, “very overweight” | UW/NW/OW/O (1.6/31.6/38.0/29.0) |
| Irani 2007 (19) |
USA 2006 | Family medicine clinic patients, except pregnant women and mentally ill patients | 356 (73.3) |
45 (18–65) | Questionnaires | n.s. | “Underweight”, “just right”, “overweight”, “obese”, “severly obese” | UW/NW/OW/O (0.6/17.7/24.7/57.0) |
| Jáuregui 2016 (e24) |
Spain, n.s. | Semiprofessional dancers | 72* (74.0) |
21.2 ± 3.1 (18–32) | Questionnaires | “What do you think of yourself in terms of weight?” | “Very overweight”, “slightly overweight”, “about the right weight”, “slightly underweight”, “very underweight” | NW (100) |
| Jeffs 2016 (e25) |
New Zealand 2011, 2013– 2015 | Pregnant women between 11–13 WG | 638* (100) | 31.2 ± 5.2 (18.2–49) | Questionnaires | “What weight do you consider yourself?” | “Underweight”, “normal weight”, “overweight”, “obese” | UG/NW/OW/O (1.1/53.3/29.3/ 16.3) |
| Johnston 2014 (e26) |
United Kingdom 1997 –1998, 2002 | Overweight and obese, working age respondents | 9089 (47.8) |
42.8 ± 9.8(25–60) | Interview and questionnaires | “Given your age and height, would you say that you are …?” | “About the right weight”, “too heavy”, “too light” | OW +O (100) |
| Kim 2018 (e27) |
South Korea 2001, 2005, 2013 | Representative cross-section without pregnant women | 16 559 (57.3) |
n.s. | Interview with standardized questionnaires | “How do you perceive your body size?” | “Very thin”, “slightly thin/normal”, “a little obese”, “severely obese” | UW/NW/OW/O (4.4/63.9/28.1/3.5) |
| Kirk 2008 (e7) |
Tonga 2004 | Patients and nurses, except pregnant women | 102 (62.6) |
35.2 ± 14.0 | Questionnaires | Rating on a scale from 1 to 5 | 1 – “underweight”, 2 – “ideal weight”, 3 – “overweight”, 4 – “obese”, 5 – “very obese” |
UW+NW/OQ/O (12.1/36.4/ 51.4) |
| Loret de Mola 2012 (e28) |
Peru 2007 | Urban residents, rural residents, migrants | 983 (53.0) |
48 (>30) | Questionnaires | “For your age, do you perceive your weight to be … ?” | ”Low weight”, “normal”, “overweight”, “obese” | UW/NW/OW/O (0.7/40.9/38.3/20.1) |
| Maruf 2012 (e29) |
Nigeria, n.s. | Health science students | 120* (55.8) |
22.3 ± 1.9(21–29) | n.s. | n.s. | “Underweight”, “normal weight”, “overweight”, “obese”? | UW/NW/OW/O (0.8/81.7/15.0/2.5) |
| Minsky 2013 (e30) |
USA 2009 | Patients with serious mental illness | 586 (48.0) |
n.s. | n.s. | n.s. | “Underweight”, “normal”, “overweight”, “obese” | UW/NW/OW/O (3.8/24.7/30.9/40.6) |
| Mogre 2014 (e31) |
Ghana 2013 | Outpatients in a type 2 diabetes clinic | 200 (77.0) |
56.2 ± 12.1 | Questionnaires | “Do you think your weight is: … ?” | “About the right weight”, “underweight”, “overweight”, “obese” | UW/NW/OW + O (7.0/61.0/32.0) |
| Mogre 2015 (e32) |
Ghana 2013 | Students, except pregnant or nursing women | 368 (35.9) |
23.0 ± 2.8 | Questionnaires | “How do you perceive your weight?” | “Underweight”, “normal weight”, “overweight”, “obese” | UW/NW/OW + O (4.9/82.1/13.0) |
| Monteagudo 2015 (15) |
Netherlands 2008–2009 | Representative cross-section of older people | 1282* (53.6) |
72.5 ± 8.1 (60–96) | Questionnaires | “How would you classify your body weight?” | “Do not know”, “underweight”, “normal weight”, “overweight”, “obese” | UW/NW/OW/O (0.4/29.0/46.4/24.2) |
| Moore 2010 (27) |
USA 2004 –2006 | African American women in urban health centers without long-term medication, pre-existing diseases, or current pregnancy | 323 (100) |
37.6 ± 13.6 | Questionnaires | “I feel I am…” | “Underweight”, “normal weight”, “overweight”, “obese” | UW/NW/OW/O (1.5/18.3/25.7/54.5) |
| Mueller 2014 (20) | USA 2009 | Outpatients in a general internal medicine clinic | 507* (50.6) |
62.9 ± 14.9 | Questionnaires | “Which of the following best describes your weight?” | “Underweight”, “about” right”, “overweight”, “obese” | UW/NW/OW/O(2.2/27.2/38.1/32.6) |
| Muhihi 2012 (e33) |
Tanzania, n.s. | Middle-aged patients | 209 (45.0) |
53.7 ± 6.1 (44–66) | Questionnaires | “How do you perceive your current body weight?” | “Underweight”, “normal for my age”, “overweight/obese” | UW/NW/OW/O (4.8/39.2/32.5/23.4) |
| Murillo 2016 (e2) |
USA 2007 –2010 | Hispanic, black, and white Americans with overweight or obesity | 7992 (48.8) | 48.3 ± 26.8 | Interview and questionnaires | n.s. | “Overweight”, “underweight”, “about the right weight” | OW + O (100) |
| Peltzer 2012 (e34) |
South Africa, n.s. | University students, except health science students | 289 (65.4) |
n.s. | Questionnaires | n.s. | “Very underweight”, “somewhat underweight”, “normal weight”, “somewhat overweight”, “very overweight” | UW/NW/OW + O (11.4/65.4/ 23.2) |
| Phetla 2017 (24) |
South Africa, n.s. | Healthcare professionals | 209* (82.4) |
37.8 ± 9.2(21–63) | Questionnaires | n.s. | “Underweight”, “normal weight”, “overweight”, “obese” | UW/NW/OW/O (2.4/24.4/21.0/ 52.2) |
| Prinsloo 2014 (e35) |
South Africa 2007 | Female patients at a healthcare center | 301* (100) |
28.3 ± 8.8(18–50) | Questionnaires | n.s. | “Underweight”, “normal weight”, “overweight” | UW/NW/OW/O (1.0/22.7/32.2/44.1) |
| Rahman 2010 (e36) |
USA 2008 –2010 | Female patients in a reproductive clinic | 2224 (100) |
21.4 ± 2.1 (18– 25) | Questionnaires | “How would you describe your weight?” | “Very underweight”, “slightly underweight”, “about the right weight”, “slightly overweight”, “very overweight” | NW/OW/O (47.8/24.8/ 27.5) |
| Rouiller 2016 (22) |
Switzerland 2009–2012 | Urban population | 4786 (53.2) |
57.7 ± 10.5 (40–80) | Interview | “Currently, how do you consider your weight?” | “Too thin”, “adequate weight”, “too fat” | NW/OW/O (44.2/38.8/17.0) |
| Shin 2015 (e37) |
South Korea 2007–2012 | Representative cross-section | 33 704 (57.6) |
n.s. | Interview | “In your opinion, how do you perceive your body?” | “Thin”, “normal”, “fat” | UW/NW/OW + O (4.5/63.5/32.0) |
| Sinhababu 2007 (e38) |
India 2004 | Students of a nursing training center | 176 (100) |
n.s. | Questionnaires | n.s. | “Thin”, “normal”, “fat” | UW/NW/OW/O (33.5/61.4/5.1/0) |
| Strassnig 2005 (e3) |
USA, n.s. | Psychiatric patients in an outpatient clinic | 143 (46.2) |
43.3 ± 8.6 | Structured interview | “Do you consider yourself now being …?” | “Underweight”, “about acceptable weight”, “slightly overweight”, “very overweight”, “extremely overweight” | UW + NG / OW/O (17.5/22.4/ 60.1) |
| Van Minnen 2011 (e39) |
Australia, n.s. | Patients with type 2 diabetes in an Australian urban community | 1272 (51.0) |
64.0 ± 11.2 | Questionnaires | “Do you perceive yourself as overweight?” | n.s. | UW + NW/ OW/O (18.1/40.0/ 42.0) |
| Veggi 2004 (e5) |
Brazil 1999 | University employees, except pregnant or nursing women and employees with BMI- influencing disease | 3498 (54.4) |
(22–59) | Questionnaires | n.s. | “Highly above ideal”, “slightly above ideal”, “ideal”, “slightly below ideal”, “highly below ideal “ | UW/NG/ OW +OA (1.6/40.4/58.0) |
| Ver Ploeg 2008 (13) |
USA 1999–2004 | Representative cross-section without pregnant or nursing women and underweight persons | 8419 (48.2) |
n.s. (≥ 20) | n.s. | n.s. | “Overweight”, “underweight”, “about the right weight” | UW/NW/OW + O (0/29.3/70.7) |
| Wang 2017 (21) |
USA 2010– 2012 | High school employees, except pregnant women and women with childbirth <6 months ago | 623 (65.0) | 44.6 ± 11.3 | Questionnaires | n.s. | “Very underweight”, “somewhat underweight”, “just right”, “somewhat overweight”, “very overweight” | UW/NW/OW/O (0/33.9/38.8/ 27.3) |
* Discrepancies between the number of study participants and the number of participants included in the analysis of the BMI category;
O, obesity; n.s., not stated; n, number of participants; NW, normal weight; SD, standard deviation; SES, socioeconomic status; WG, weeks’ gestation; UW, underweight; OW, overweight