Development and validity of the Japanese version of body shape silhouette: relationship between self-rating silhouette and measured body mass index.

We devised new body shape silhouettes to more accurately reflect Japanese body sizes. Our aim was to assess the association between measured body mass index (BMI) and body size through self-selection of nine figure scales. This study was comprised of 4808 men and 1093 women aged 35-71 years. Subjects were asked to identify the silhouettes that most accurately represent their current body size. BMI was calculated from measured height and weight based on annual health checkups. Spearman's correlation coefficients between silhouette ratings and BMI were 0.73 in men and 0.80 in women. Moreover, mean BMIs increased in value with increasing silhouette numbers in both genders (trend p < 0.01 for both). Simple linear regression models predicting BMI based on silhouette ratings showed a good fit, with silhouette self-selection statistically explaining 54.0% of BMI variance in men and 62.5% in women. Receiver operating curves showed that areas under the characteristics curves were higher than 0.8 for obesity and thinness in both genders. These findings suggest that our scale is a promising tool for examining body size and image among Japanese adults.