Prevalence of overweight and obesity among 7-9-year-old children in Aveiro, Portugal: comparison between IOTF and CDC references.

Objective: To estimate the prevalence of overweight and obesity in schoolchildren from Aveiro, Portugal, according to two criteria: the International Obesity Task Force (IOTF) and the US Centers for Disease Control and Prevention (CDC) cut-offs.

Design: Weight, height and waist circumference were measured. Using the BMI, gender- and age-specific prevalences of overweight and obesity were determined according to the IOTF cut-offs extrapolated from an adult BMI of 25 and 30 kg/m2 and the CDC cut-off values of 85th and 95th BMI percentile.

Setting: Aveiro, Portugal.

Subjects: A random representative sample of 905 children (457 boys; 448 girls) aged 7-9 years.

Results: The prevalence of excess weight (overweight and obesity) was lowest according to IOTF cut-offs compared to CDC (28.1 % v. 31.2 %), especially obesity (8.1 % v. 14.0 %). However, the CDC and IOTF criteria have a strong agreement (Cohen's k = 0.755; P < 0.001). There were significant differences in excess weight between boys and girls according to the CDC (26.9 % v. 35.7 %; P = 0.003). Obese children are younger and the majority present abdominal obesity.

Conclusions: The present study shows a high prevalence of excess weight in Aveiro children, similar to other Portuguese regions and among the highest in Europe, especially in the female gender. The IOTF cut-off values give a lower prevalence of excess weight, namely obesity.