WEDNESDAY, July 9 (HealthDay News) -- Teen girls who spend a lot of time on the Internet are more likely to see their weight creeping slowly up than adolescents who spend less time in front of the computer screen, new research shows.
And the association between computer use and weight held true even when the researchers accounted for the amount of exercise the girls were getting. The Harvard researchers also found that a lack of sleep and alcohol consumption were associated with increasing weight.
"We found more weight gain -- after adjustment for height growth and other factors including physical activity -- for females who spent more recreational time on the Internet, for those getting the least sleep, and for those drinking the most alcohol," said study author Catherine Berkey, a biostatistician at Brigham and Women's Hospital and Harvard Medical School in Boston.
Results of the study were published in the July issue of The Journal of Pediatrics.
Berkey's study included data on more than 5,000 teenage girls from across the United States. The girls were between the ages of 14 and 21. In 2001, they completed surveys detailing their Internet use, sleep habits, coffee consumption, alcohol consumption and physical activity. The girls' weight and height were measured in 2000 and then again in 2001.
The researchers asked the girls to report only their recreational Internet usage -- not usage for school or work.
Teen girls who spent more than 16 hours a week on the Internet were almost twice as likely to have a change in their body-mass index, even after the researchers controlled for sleep, coffee and alcohol use. Once the researchers factored in physical activity and TV and video game use, girls with the most Internet use were still about 57 percent more likely to have gained weight.
Girls over 18 who slept less than five hours a night on average, who consumed two or more servings of alcohol weekly and who spent more time on the Internet averaged about a four-pound weight gain during the year.
