Revista Brasileira de Epidemiologia
Print version ISSN 1415-790X
SILVA, Kelly Samara da et al. Associations between physical activity, body mass index, and sedentary behaviors in adolescents. Rev. bras. epidemiol. [online]. 2008, vol.11, n.1, pp.159-168. ISSN 1415-790X. http://dx.doi.org/10.1590/S1415-790X2008000100015.
OBJECTIVE: The objective of this study was to analyze the associations of body mass index (BMI) with physical activity, sedentary behaviors (TV, computer/videogames) in a representative sample (n=5,028) of adolescents (15-19 years) in the State of Santa Catarina, Brazil. METHODS: Data was collected using a validated health behavior questionnaire developed for adolescents. Excess body weight was determined according to the international BMI tables developed for adolescents. Students were classified as not being physically active if they reported having less than 300 minutes of moderate/vigorous physical activity (MVPA) per week. Two or more hours a day was considered excess screen time (TV, computer, games). RESULTS: Excess body weight was more prevalent (p<0.001) among boys (12.7%) than girls (7.9%), but inadequate physical activity was more prevalent (p<0.001) among girls (37%) than boys (21%). Less active boys had a greater chance (74%) of having excess body weight when compared to active ones. Among girls, those belonging to families with lower income (OR=1.85) and living in urban areas (OR=2.22) were at greater risk of having excess body weight. An inadequate level of physical activity was seen among boys with excess screen time or excess body weight. Also, working girls were more likely (54%) of being less active. CONCLUSIONS: Excess body weight was more prevalent among boys, although they were more active than girls. For boys, excess body weight was inversely associated with physical activity, while, for girls, it was more prevalent among those with lower income and who lived in urban areas.
Keywords : Overweight; Obesity; Physical activity; Computer; Television; Adolescent.