Associations among Body Mass Index, sedentary behavior, physical activity, and academic performance in schoolchildren

BACKGROUND: Physical inactivity and sedentary behavior are common among middle and high school grade children. This study aimed to determine the relationship among Body Mass Index (BMI), sedentary behavior, physical activity (PA), and overall academic performance of students. METHODS: This is a cross sectional study; 357 students of mean age 12.65±1.68 years were enrolled. PA was subjectively assessed using the Physical Activity Questionnaire for Children (PAQ-C) and Godin Leisure-Time Exercise Questionnaire (GLTEQ). Sedentary behavior was assessed as hours spent on watching television, playing video games, computer use, and homework. Grade point average (GPA) was calculated to determine their overall academic performance. Participants were divided into two groups based on their GPA. Independent t-test was used to analyze BMI, sedentary time, and PA between the groups. Correlation analysis was performed to determine the associations among BMI, sedentary time, physical activity, and academic grades. RESULTS: There was no significant difference in BMI and the level of PA between the two groups. However, significant differences were observed in sedentary time (ST) spent watching television (P=0.04), total screen time (P=0.02), and total ST (P=0.002). There were weak negative correlations among BMI (r=-0.14, P<0.05), total screen time (r=-0.12, P<0.05), and academic scores; however, there was no association with any PA measures. CONCLUSIONS: A weak correlation was noted between BMI and sedentary characteristics, with respect to academic performance. As academic performance is negatively associated with body mass index and screen time, public health interventions are needed to reduce their time spent on leisure time sedentary activity, watching television, and computer use.