Body adiposity and levels of physical activity in adolescents

The objectives of the study were to compare body adiposity levels expressed by means of Body Mass Index (BMI) and waist circumference (WC) with the American reference of the Center for Disease Control and Prevention (CDC-2012); and to analyze whether these body adiposity levels differ among adolescents by physical activity categories. A cross-sectional descriptive study was carried out with 765 adolescents (432 boys and 333 girls). The selection of the sample was non-probabilistic (quotas). We included 4 schools from the city of Talca, Chile. The age interval ranged from 10.0 to 18.9 years old. Weight, height, and WC were evaluated, and BMI was calculated. A PA questionnaire was applied. There were no significant differences in BMI and WC with the reference of CDC-2012 in adolescents of both genders (p <0.05). Prevalence of low PA level was observed (5.3% for boys, and 14.7% for girls), as well as moderate PA level (47.7% in boys, and 63.4% girls) and high PA level (47,0% in boys, and 21.9% in girls). Positive relationship was found between the indicators of body adiposity (BMI and WC) in the three categories (low level: r = 0.94 boy, and r = 0.87 girls; moderate level: r = 0.87 boys, and r = 0.86 girls; and high level of PA: r = 0.85 boys, and r = 0.63 girls). The adolescents in this study reflect similar patterns of corporal adiposity as in the CDC-2012 for both genders. In addition, schoolchildren classified with high level of PA reflected lower abdominal adiposity than those in the other PA categories.