Novos parâmetros de referência do índice de massa corporal para classificação do estado nutricional de crianças de 06 a 10 anos na cidade de Montes Claros - MG

Abstract

The childhood obesity is nowadays a major public health problem worldwide, triggering a series of health problems to young populations. The objective of the present study was to establish new Body Mass Index (BMI) parameters for the nutritional state classification in children aged from 06 to 10 years old. Two studies were performed: a systematic review with meta-analysis (SRMA) and an epidemiological cross-sectional study. The SRMA gathered Brazilian studies on the childhood and adolescence obesity prevalence in different regions. 70 studies were selected in the following databases: Scielo, Pubmed, Scopus, Latindex and ISI, and the overweight prevalence found was 23% (IC: 22-25%; p<0.01) with 99.18% (p<0.01) heterogeneity. In the systematic review, it was possible to identify a disparity in the BMI classification according to distinct adopted criteria, which allowed us to detect the need for a new BMI classification via a cross-sectional study. The cross-sectional study sample was 3,863 children aged from 06 to 10 years old in Montes Claros, MG. Body mass and height were assessed, following the BMI calculation. The reference values were obtained from the Lambda, Mu and Sigma (LMS) method. The semi-annual distribution values were obtained after each stratum curve has passed a smoothing process via using the fourth-degree polynomials according to sex and arithmetic averages interpolation. The 3%, 85% and 95% percentiles were calculated for the classification as underweight, overweight and obese, respectively, according to sex and age. After the L, M and S parameters values tabulation into semi-annual intervals, it was possible to construct the graph with seven percentiles of the BMI distribution, being presented new BMI parameters for children aged from 06 to 10 years old in Montes Claros. The new parameters were 17.5kg/m² for underweight, 25kg/m² for overweight and 30kg/m² for obesity, respectively. It is concluded that the use of the traditional BMI reference values in the Montes Claros population may overestimate the underweight and underestimate the overweight/obesity prevalence. Therefore, it is advisable the performance of studies with periodic updates for the nutritional state classification of child and adolescents via BMI, according to the different population characteristics.