Body composition and television viewing among high school adolescents residing within the Tlokwe municipality : PAHL study

Abstract

Television viewing is one of the most easily modifiable causes of obesity among children. The purpose of this study was to determine the relationship between body composition and TV viewing among adolescents attending high schools in the Tlokwe municipality area of the North West province of South Africa. A cross-sectional study design which is part of the Physical Activity and Health Longitudinal Study (PAHLS) was followed on 154 learners (58 boys and 96 girls) who were aged 14 years in the Tlokwe municipality area. All the learners underwent anthropometric measurements of height, weight, and two skinfolds (triceps and subscapular skinfolds). Percentage body fat (%BF) was calculated from the two skinfolds according to Slaughter‟s et al. (1988) equation. Children were classified into three groups (viz. normal, overweight and obese) according to BMI cut-off point suggested by Cole et al. (2000). Pearson correlation coefficients were used to determine the relationship between television viewing and body composition. The results show respectively high prevalence of overweight and obesity in girls (10.4%; 6.3%) as compared to the prevalence of 5% overweight in boys. With regard to TV viewing, the results show that 54% of the total group watch TV more than two hours a day, while only 11% watched TV less than one hour a day. The results show that the group that watches TV for more than 3 hours had high BMI (21.27kg/m²) and body mass (51.54kg). The group that watches TV for 1-2 hours had low BMI (18.36kg/m²) and body mass (44.79kg). There was a statisitcal significant relationship between BMI and body mass (p=0.001). A significant positive relationship between body mass and TV viewing (r=0.56; p=0.05) in overweight group was found, whilst in the obese group strong significant positive relationship was observed between percentage body fat and TV viewieng (r=0.94; p=0.01). It can be concluded that girls were more overweight and obese respectively as compared to the boys. Furthermore, both boys and girls had high percentages of TV viewing for more than two hours a day. In addition, the results indicated that adolescents who watched TV more than 3 hours are heavier and fatter. Therefore, it is recommended that parents and educational heads should encourage periods of daily physical activity. In addition, it is also important that parents play a more positive role in limiting the amount of hours their children spent watching television.