[Body mass index in the school age children and youth from the city of Lodz]

Abstract

Excessive body mass in children and youth constitutes each year a more increasing problem in our country. Early diagnosis based on current appropriate norms and recommendations of main pediatric and scientific societies appears to be of great importance.

The aim of the study: Percentile distribution of body mass index (BMI) for children and adolescents (aged 7-19 years) dwelling in Lodz were constructed and compared with the norms included in the International Obesity Task Force (IOTF) project.

Material and methods: A total of 26,542 children and adolescents (13,358 girls and 13,184 boys) participated in the study. Measurements of basic anthropometric parameters were performed and BMI determined in all the subjects. The LMS method was used to construct the BMI percentile distributions. Sex dimorphism of the BMI as well as the differences between the border values of BMI distribution for children from Lodz and the IOTF norms were analysed.

Results: The children from Lodz, particularly girls, reveal significantly lower BMI values defining obesity (c95) as compared to the IOTF norms. The maximal difference concerned 18-year-old girls and was 2.62 kg/m2 (9.1%). BMI values indicating overweight in the Lodz children (c85) were more similar to the international norms of IOTF (maximal difference around 5%).

Conclusions: The results confirm justifiability of using a local norm as a criterion for evaluation of obesity at the developmental age. Application of the IOTF norms in the assessment of obesity prevalence in children and youth in Poland may be associated with a considerable underestimation of this problem.