Associação entre diferentes níveis de intensidade de atividade física e índice de massa corporal em adolescentes

Abstract

The stimulus for physical activity (PA) is considered an important part of policies to promote health and prevent obesity, however the association between the different categories of physical activity intensity and weight gain is not completely established. This approach requires precise measurements of physical activity, which does not exist in the vast majority of studies. This study aims to assess the association between different levels of PA intensity and the body mass index (BMI) of adolescents. The study was carried out on 61 male adolescents with a mean age of 11.6 years (± 1.4), who had data on acceleration over a week, allowing to evaluate the average daily time involved in each level of PA intensity, as well as the absence of PA. Anthropometric data were also collected. The association between each intensity of PA was assessed, these being sedentary behavior (SB), light physical activity (LPA), moderate physical activity (MPA) and vigorous physical activity (VPA) with the BMI and how much each category explains the variance, according to the coefficient of determination (R - square) by means of linear regression. As a result, in the crude model only VPA showed a statistically significant association with BMI (p ≤0.05), where for each unit of time spent in this category, the BMI decreased by an average of -0.28 units. The VPA determination coefficient explained 15% of the BMI variance. When the model was adjusted for age, both MPA and VPA showed high statistical significance (p = 0.006 and p = 0.003, respectively). Although both categories of intensity have been negatively associated with BMI, VPA has a greater effect. The time spent in MPA and VPA adjusted for the age variable showed a negative association with the adolescents' BMI, but LPA or SB were not associated with BMI. Although the sample is small, the premise that any physical activity may have an impact on weight loss is not confirmed and the data suggest that only the performance of VPA has an important impact on BMI.