Abstract
The body mass index (BMI) of school children in Taiwan is markedly increasing. According to statistical data from the Taiwan Ministry of Education, the prevalence of obesity in school children from the southern part of the country is the highest in Taiwan. Thus, exploring the factors influencing BMI in elementary school children from southern Taiwan is crucial. This study investigated the influencing factors including physical activity levels, sedentary behaviors, dietary habits, and perceived body shape on the BMIs of elementary school children from southern Taiwan. A cross-sectional design was used, and the participants consisted of 3251 fifth-grade students (1628 boys, 50.1%; 1623 girls, 49.9%). The average BMI values for boys and girls were 19.69 and 18.70 (kg/cm) respectively. Statistically significant associations were observed between BMI and sex, 31-60 min of daily vigorous or moderate physical activities levels, length of time spent watching television, time spent on video games or the computer, and intake of vegetable or meat gravy with rice (p < 0.001). Perceived body shape also affected the BMI of school children. The results of this study enable educational institutions in Taiwan to understand the factors affecting the BMI of school children and use this information as the basis for future healthy body weight policies.