# Table 1 Differences between mean self-reported (SR) and measured BMI values (SR BMI – measured BMI). Paired t-tests (2-tailed) assessing differences between self-report (SR) and measured BMI values are presented by sex and country for older (50+ years old) and younger (18–49 years old) individuals, with degrees of freedom (df)

Older men Older women Younger men Younger women
China 23.5-23.6 = −0.1 24.17-24.22 = −0.6 23.5-23.2 = 0.2 23.1-23.4 = −0.3
t(5623) = −1.03 t(6439) = −0.808 t(678) = 1.435 t(869) = −2.400*
India 23.8-20.7 = 3.1 27.0-21.3 = 5.7 22.7-20.6 = 2.1 24.1-20.7 = 3.4
t(1528) = 8.711*** t(964) = 8.815*** t(575) = 5.196*** t(1325) = 7.534***
Mexico 28.0-28.3 = −0.3 28.8-29.3 = −0.5 28.3-28.7 = −0.4 28.4-29.0 = −0.6
t(286) = −0.837 t(308) = −2.740** t(48) = −1.664 t(79) = −1.935
Russia 27.0-27.3 = −0.3 29.2-29.7 = −0.4 25.4-26.3 = −0.9 26.0-26.4 = −0.4
t(1235) = −3.540*** t(2202) = −6.888*** t(143) = −0.914 t(234) = −2.252*
South Africa 31.2-29.2 = 2.0 33.4-32.6 = 0.8 30.1-29.1 = 0.9 31.2-29.9 = 1.4
t(406) = 3.016** t(508) = 1.310 t(36) = 0.534 t(51) = 0.762
1. Note: Negative values correspond to lower SR BMI than measured BMI values while positive values reflect higher SR than measured BMI values. The number of asterisks indicates the level of significance (* = p < 0.05, ** = p < 0.01, *** = p < 0.001) in chi-square test