eTable 2. Influence of socioeconomic status, education, income, and work on accurate BMI categorization.

Study	Categories	Comparison*1	Prevalence of accurate BMI categorization	Result [95% CI]
Socioeconomic status
Akgöz 2017	Lower middle class, middle class, upper middle class, and upper class	Lower middle class vs. upper middle class and upper class	56/197 (28.4%) vs. 32/70 (45.7%)	OR: 0.47 [0.27; 0.83]
Griger 2015	Low, middle, high	Low vs. high	Women: 49/98 (50.1%) vs. 139/247 (56.3%)Men: 55/95 (58.4%) vs. 92/172 (53.5%) Total: 104/193 (53.9%) vs. 231/419 (55.1%)	OR*2: 0.95 [0.68; 1.34]
Education (highest educational attainment)
Akgöz 2017	Primary school or less, secondary school & upper secondary school, university & higher	Primary school vs. university	49/180 (27.2%) vs. 25/46 (54.3%)	OR: 0.31 [0.16; 0.61]
Akindele 2017	Primary school, secondary education, tertiary education, graduates	Primary school vs. graduates		aOR: 1.02 [0.50; 2.11]
Akinpelu 2015	Illiterate, primary, secondary, tertiary education	Illiterate vs. tertiary education	44/78 (56.4%) vs. 10/21 (47.6%)	OR: 1.42 [0.54; 3.74]
Barichella 2011	Years of education	1 year less education		aOR: 0.84 [0.71; 1.01]
Dorosty 2014	≤ 12 years, >12 years	≤ 12 years vs. >12 years	61/94 (64.9 %) vs. 320/448 (71.4 %)	aOR*4: 0.45 [0.21; 0.96]
Irani 2007	<8 years, >8 years but not university, university, graduates	<8 years vs. university or graduates	6/60 (10.9 %) vs. 55/149 (36.9 %)	OR: 0.19 [0.08; 0.47]
Jeffs 2016	Attended high school, secondary school leaving certificate, university degree	Attended high school, vs. university degree	67/121 (55.4%) vs. 276/382 (72.2%)	OR*3: 0.48 [0.31; 0.73]
Minsky 2013	Secondary school-leaving certificate or less, attended university	Secondary school-leaving certificate or less vs. attended university	171/427 (40.3%) vs. 80/162 (49.4%)	OR: 0.68 [0.48; 0.99]
Monteagudo 2015	Low (primary school), middle (secondary school), high (university)	Low vs. high	144/293 (49.0 %) vs. 173/271 (63.9 %)	OR: 0.55 [0.39; 0.77]
Mueller 2014	Less than secondary school-leaving certificate, secondary school-leaving certificate, attended university, university degree, graduates	Less than secondary school-leaving certificate vs. graduates	n.s./31 vs. n.s./122	aOR*4: 0.41 [0.16; 0.97]
Murillo 2016	No secondary school-leaving certificate, secondary school-leaving certificate	No secondary school-leaving certificate vs. secondary school-leaving certificate	2448/3708 (66.0%) vs. 3154/4284 (73.6%)	OR*3: 0.41 [0.16; 0.97]
Rahman 2010	Attended secondary school, secondary school-leaving certificate, attended university	Attended secondary school vs. attended university	OW: 183/259 (70.6%) vs. 319/370 (86.2%)NW: 167/197 (84.8%) vs. 270/330 (81.8%) Total: 350/456 (76.8%) vs. 589/700 (84.1%)	OR: 0.62 (0.46–0.84)
Rouiller 2016	Low (compulsory education or apprenticeship), middle (upper secondary school), high (university degree)	Low vs. high	1819/2513 (72.4%) vs. 788/1040 (75.8%)	OR: 0.84 [0.71; 0.99]
Income
Akgöz 2017	Income < expenses, income = expenses, income > expenses	Income < expensesvs. income > expenses	60/191(31.4%) vs. 7/10 (70%)	OR: 0.20 [0.05; 0.79]
Harris 2016	<$ 15 000. ≥ $ 15 000	<$ 15 000 vs. ≥ $ 15 000	6/72 (8.3%) vs. 13/46 (28.3%)	OR: 0.23 [0.08; 0.66]
Rahman 2010	< $ 30 000. ≥ $ 30 000	<$ 30 000 vs. ≥ $ 30 000	OW: 716/923 (77.6%) vs. 120/147 (81.6%)NW: 680/814 (83.5%) vs. 122/139 (87.8%) Total: 1396/1737 (80.4%) vs. 242/286 (84.6%)	OR: 0.74 [0.53; 1.05]
Work
Akindele 2017	Unemployed, retired, employed	Unemployed vs. employed		aOR*4: 0.39 [0.16; 0.94]
Akinpelu 2015	Unemployed, blue-collar, white-collar	Unemployed vs. white-collar	24/34 (70.6 %) vs. 7/19 (36.8 %)	OR: 4.11 [1.25; 13.51]

*¹Lowest vs. highest category, *² Analysis was performed for normal-weight persons; in the study a comparison with the middle category was undertaken (with reporting of adjusted ORs), *³ adjusted ORs (aOR) are only reported for overestimation and underestimation, *⁴ Recalculation from inverse data; n.s., not stated; NW, normal weight; OW, overweight