Variation of BMI and anthropometric indicators of abdominal obesity in Brazilian adolescents from public schools, 2003-2008.

OBJECTIVE

The aim of the present study was to compare BMI and anthropometric indicators of abdominal obesity in Brazilian adolescents from public schools between 2003 and 2008.

DESIGN

A comparison of anthropometric indicators in adolescents was done based on two cross-sectional surveys conducted in 2003 (n 530) and in 2008 (n 498). BMI (= weight/height2), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were evaluated. The age-adjusted means were compared between the two studies by linear regression and the percentile values were compared by quantile regression. A P value <0·05 was adopted for statistical significance.

SETTING

Metropolitan area of Rio de Janeiro, Brazil.

SUBJECTS

Two probabilistic samples of students aged 15-19 years old, from public schools.

RESULTS

There was a decrease in boys' mean WC (72·9 cm v. 70·9 cm, P = 0·01) and an increase in girls' mean BMI (21·1 kg/m2 v. 22·0 kg/m2, P = 0·03). Among boys, the WC, HC and WHtR percentiles were lower whereas the WHR percentiles were higher in 2008 than in 2003. Among girls, the percentiles of all measures were higher in 2008, except for WHR.

CONCLUSIONS

Anthropometric measures among boys tended to decrease, while among girls there was a tendency to increase from 2003 to 2008, indicating an important gender effect and a higher morbidity risk associated with excess body fat in girls. The school setting offers opportunities for interventions to address this situation.