Purpose: Weight status-referenced pedometer step-count guidelines for young people have been developed for populations from high-income countries and may not be applicable to middle- and low-income countries. The objectives of this study were 1) to develop cut-off points for pedometer-determined step count in young Brazilians using waist circumference (WC) as a reference criterion, and 2) to analyze the capacity of previous recommendations to discriminate abdominal obesity in the sample studied.
Methods: A cross-sectional study was conducted on 1,044 schoolchildren (456 boys) aged 6-17 years from Northeastern Brazil. WC was measured and daily step counts were determined with a pedometer.
Results: The area under the curve (AUC) of step count was significant for boys (AUC = 0.55; 95%CI: 0.50-0.59) and girls (AUC = 0.57; 95%CI: 0.53-0.61). Our cut-off points (14,414 and 11,355 steps for boys and girls, respectively) were more balanced in terms of sensitivity and specificity compared with previous recommendations. The use of previous guidelines to classify step count in the sample provided very low sensitivity or specificity and wide variation in the prevalence of insufficient physical activity (39.3-77.0%).
Conclusions: A universal step-count recommendation for young people may not be adequate and specific guidelines seem to be necessary for different countries or regions.
Keywords: adolescent; child; exercise; motor activity; obesity.