Influence of TV/Computer Watching on BMI and Physical Activity Participation in Chinese Children and Youth

Abstract

Studies were found to report the associations among TV watching, physical activity participation and body composition in US youth and Pima Indian adults. Limited investigation is found to report these associations in Chinese children and youth. PURPOSE: To examine the association among TV/Computer watching time, physical activity participation and body mass index in Chinese children and youth. METHODS: A total of 1, 495 Chinese children and youth were recruited through a citywide physical fitness and activity survey in Hong Kong in the year 2005–2006, to complete a questionnaire on TV/computer watching time and a Physical Activity Rating for Children and Youth (PARCY; Hui, 2005). PARCY was a 0–10 rating scale asking respondents to rate their current physical activity (PA) level on a continuum of 0 to 10, according to different combinations of weekly physical activity frequency, duration, and intensity. The higher the rating, the higher the PA level. Body weight and height of participants were also measured by certified fitness testers using standardized scales and stadiometers. RESULTS: Approximately 34% of Chinese children and youth spent 2 hours or more daily on TV/Computer watching. 17.1% spent 3 hours or more while 7.4% spent 4 hours or more daily. ANCOVA (age as covariate) revealed that there was a significant difference in body mass index (BMI) between different levels of TV/Computer watching time for boys (p <.01) and for girls (p<.05). For those who spent 3 hours or more daily on TV/Computer watching, their mean BMI was 19.7 and 15.7% were overweight, as compared to those who spent less than one hour, their mean BMI was 17.2 and only 8% were overweight. ANCOVA (age as covariate) also revealed significant difference in mean PA rating between different level of TV/Computer watching time in girls (p<.05) but not in boys. The data also demonstrated that watching TV/Computer for 1 hour or more was a critical point for significant decrease in PA participation. CONCLUSION: Strong associations among TV/Computer watching time, BMI, and PA participation were evident. More than one hour of TV/Computer watching daily marks a significant increase in BMI and decline in PA participation. Parents should monitor TV/Computer watching time of their children wisely for maintaining a healthy BMI and sufficient PA participation.