Background: This study investigates whether the amount of time that Korean adolescents spend on the Internet per day is related to their weight status.
Methods: For this purpose, we analyzed data from the 2009 Korea Youth Risk Behavior Web-based Survey-V (KYRBWSV), in which 72,399 students from the 7th to the 12th grade participated. We assessed the relationship between the amount of time spent on the Internet per day and body mass index (BMI) by using multivariate logistic regression analysis.
Results: For boys, the odds ratio (OR; confidence interval (CI): 95%) between becoming overweight and the amount of time spent on the Internet per day was 1.225 (1.042-1.441; P=0.014) for >4 hour. The ORs (CI: 95%) between becoming obese and time spent on the Internet per day were 1.238 (1.096-1.399; P=0.001) for >2-â¤3 hours, 1.208 (1.021-1.428; P=0.027) for >3-â¤4 hours, and 1.303 (1.109-1.532; P=0.001) for >4 hours. For girls, the ORs (CI: 95%) between becoming overweight and time spent on the Internet per day were 1.265 (1.089-1.469; P=0.002) for >2-â¤3 hours and 1.338 (1.080- 1.659; P=0.008) for >3-â¤4 hours. The ORs (CI: 95%) between becoming obese and amount of time spent on the Internet per day were 1.239 (1.014-1.513; P=0.036) for >2-â¤3 hours and 1.541 (1.182-2.010; P=0.001) for >3-â¤4 hours.
Conclusion: Korean adolescents who spend more time on the Internet are predisposed to weight-related problems, regardless of age, time spent in physical exercise, mental stress, sleep duration, etc.
Keywords: Adolescent, Youth Risk Behavior, Web, Internet, Obesity, Korea
Obesity has become a serious social and public health problem throughout the world. In 2011, the World Health Organization (WHO) reported that in 2008, 1.5 billion adults (aged 20 and older) were overweight. Of these, more than 200 million men and nearly 300 million women were classified as obese. About 65% of the world's population were said to live in countries where overweight and obesity kill more people than underweight. Finally, it was reported that in 2010, nearly 43 million children under the age of five were overweight (1).
Excessive weight is known to cause adverse health effects such as cardiac disease, musculoskeletal disorders, stroke, type II diabetes, and cancers (1). Given that approximately 80% of obese adolescents become obese adults, it is important to prevent obesity during adolescence (2-3).
Sedentary lifestyle has contributed to an increase in the prevalence of overweight and obesity (4-6), and television watching has been a major factor, particularly for children and adolescents (7). Over the past 20 years, many researchers have examined the relationship between television watching and obesity and found decreased time for physical activity, decreased resting metabolic rate (8-9), and increased energy intake (10). Recently, attention has shifted to the influence of food and beverage advertising that targets adolescent viewers as an important variable of weight status (11).
Aside from television, other components of sedentary lifestyle today include using the Internet, playing computer games, using the telephone, reading for fun, and listening to the radio (12). More investigative studies are needed to address the newer forms of sedentary behavior, particularly time spent on Internet use.
The Internet browser is a relatively new device, so early studies found a low prevalence of Internet use and no relationship to obesity (13). However, with computer use rising rapidly, more recent studies have reported controversial results-that there is no relationship (14) or that there may be a relationship (15-16).
In the Republic of Korea, the number of Internet users has grown dramatically. Internet penetration in Korea is the highest in Asia, reaching 81% of the population (17). As a result of increasing Internet use, there has been an increase in physical inactivity among teenagers. …