Agreement between self-assessment of body image and measured body mass index in the Brazilian adult population.

Silhouettes are used in the self-assessment of one's body size, shape and satisfaction. This technique can be helpful in intervention studies and in household studies in which body size measurements are not feasible. Despite its popularity, few studies have validated the Stunkard Figure Rating Scale (SFRS) to assess body image (BI) or nutritional status (NS). The present study assessed the agreement between self-assessment of BI by SFRS and measured BMI in adults from a national household survey in Brazil (n = 11247; 57.2% women, aged 20-99y). The subjects were asked to choose a silhouette from the SFRS that most resembled their current status prior to measures of body mass and stature. BMI-derived NS was then matched to the SFRS. The prevalence of overweight and obesity (OB) was 34.4 and 19.0%, respectively. Weighted kappa between SFRS and BMI was 0.45 and 0.43 and Spearman's correlation coefficient was 0.64 and 0.59 for women and men, respectively. Sex-specific receiver operating curves indicated that the silhouettes correctly (area under the curve > 0.80) identified OB and underweight (UW). In conclusion, SFRS provides only reasonable results when estimating the BMI distribution but it works well to identify OB and UW in the Brazilian adult population.

Estado nutricional antropométrico autoavaliado e medido em adultos de amostra probabilística de domicílios brasileiros / Nutritional status self-assessed and measured in adult probability sample of Brazilian households

A autoavaliação da imagem corporal é uma técnica que utiliza escalas de silhuetas (ES) compostas por figuras ou fotos que geralmente vão da mais magra a mais gorda e escolhe-se a figura com a qual mais se identifica em relação ao seu estado nutricional (EN)...A média de IMC foi de 26,4kg/m2 (0,1) entre as mulheres e 25,7kg/m2 (0,1) entre os homens. Os valores do CCS foram 0,64 e 0,59 (p,0,0001) nas mulheres e homens, respectivamente. Os valores de k simples e ponderado foram de 0,32 e 0,45 para mulheres e 0,31 e 0,44 nos homens, respectivamente. As ES de Stunkard et al (1983) fornecem valores apenas razoáveis para a autoavaliação do EN de adultos brasileiros