Abstract

This study verified the diagnostic accuracy of the nutritional status classified by the international height and BMI references of the World Health Organization (WHO) (WHO/2007), International Obesity Task Force (IOTF/2012) and MULT (2023). The data pool was composed by 22 737 subjects aged five to 16 years from the Santos and Porto Alegre surveys. A correlation matrix between the z-scores of the BMI references and the skinfold measurements was calculated through the Pearson correlation coefficient (r), and the subject's nutritional status was classified according to the international growth references. The accuracy for diagnosing obesity was performed separately by sex and using the 95th percentile of the triceps and subscapular skinfold sum, while Lin's concordance coefficient, Bland-Altman method and the Cohen's Kappa coefficient (Kappa) were used to verify the concordance and reliability among the BMI references. The correlation matrix showed a high positive correlation among the BMI z-scores (r >= 0 center dot 99) and among the skinfold measurements (r >= 0 center dot 86). The prevalence of stunting was higher when applying the MULT reference (3 center dot 4 %) compared with the WHO reference (2 center dot 3 %). The Bland-Altman plots showed the lowest critical difference (CD) between the height references of WHO and MULT (CD = 0 center dot 22). Among the BMI references, the WHO obesity percentile presented lower performance than MULT for boys, presenting a lower +LR value (WHO = 6 center dot 99/MULT 18 years = 10 center dot 99; 19 years = 8 center dot 99; 20 years = 8 center dot 09) for the same -LR values (0 center dot 04). Therefore, MULT reference holds promise as a valuable tool for diagnosing childhood obesity, particularly when considering sex differences. This enhances its suitability for assessing the nutritional status of Brazilian schoolchildren.