Girls moving through adolescence may experience unhealthy levels of weight gain and a new study in The Journal of Pediatrics analyzes the effect of Internet usage, sleep, and alcohol and coffee consumption.

Dr. Catherine Berkey and colleagues from Harvard Medical School, Brigham & Women's Hospital, and Washington University led the Growing Up Today Study (GUTS), which surveyed more than 5000 girls between the ages of 14 and 21 years from all 50 states. They asked the girls to reflect on their weekly habits over the past year and report the following: 1) hours of sleep per night; 2) time spent on the Internet (excluding time for work or school); 3) number of alcoholic beverages consumed; and 4) number of coffee beverages consumed. The girls also reported their height and weight at the beginning and end of the one-year study.

The researchers found that more Internet time, more alcohol consumption, and less sleep resulted in extra weight gain during the study year.

Girls aged 18 years or older who consumed 2 or more alcoholic beverages a week or slept less than 6 hours a night gained more weight than other study participants.

In fact, when combined with Internet use, girls in this group have the potential to gain four extra pounds a year. The researchers did not find a link between coffee consumption and weight gain, although they point out that this information was collected before high calorie coffee drinks became popular.

The authors suggest that recreational Internet time, alcohol consumption, and lack of sleep may go unnoticed as causes of gradual weight gain. Dr. Berkey expressed concern that "these behaviors may promote gradual gains in body weight, but the girls and their parents may not understand why."

To help maintain a healthy body weight, she encourages adolescent girls to replace recreational Internet time with more sleep, and avoid alcoholic beverage consumption.

Article: "Weight Gain in Older Adolescent Females: The Internet, Sleep, Coffee, and Alcohol" by Catherine S. Berkey, ScD, Helaine R.H. Rockett, MS, RD, Graham A. Colditz, MD, DrPH. Journal of Pediatrics, DOI 10.1016j.jpeds.2008.04.072