A study published in the April 2004 issue of Archives of Pediatrics & Adolescent Medicine (2004, 158 , 385–90) says lack of vigorous exercise is the main reason kids ages 11–15 are overweight.
Researchers at the University of California, San Diego (UCSD), School of Medicine examined 878 youngsters to determine how diet, physical activity and sedentary behaviors related to overweight status. They found that 45.7% of the 878 children were either at risk for becoming overweight or already classified as overweight by the standard body mass index (BMI) for age.
According to a UCSD press release, each participant wore an accelerometer, “a small device worn on a belt that stores data on amount and level of physical activity every minute for a week.” Investigators found that both girls and boys in the normal-weight group participated in 2–4 more minutes of vigorous physical activity per day than the at-risk and overweight group. Researchers also found that boys in the at-risk group watched 141.5 minutes of television per day, compared with 108.4 minutes per day for the normal-weight boys. No group difference in television watching was noted for girls.
In their final report, the study authors said these findings suggest that “adolescents continue to require interventions that target multiple aspects of physical activity and nutrition.”