WEDNESDAY, Dec. 15, 2010 (HealthDay News) -- Starting school at a younger age may reduce girls' risk of becoming obese years later, a new study suggests.
Researchers analyzed data from nearly 6,000 girls in the U.S. National Longitudinal Survey of Youth.
Girls who were eligible to start school at a younger age than most of their classmates were significantly less likely to be overweight during adolescence. Girls who started school at an older age than most of their classmates were more likely to be overweight in adolescence, the investigators found.
A similar effect was not found in boys, said lead author Ning Zhang, of the University of Rochester School of Medicine, and colleagues.
The study was published online Dec. 14 in the Journal of Adolescent Health.
Peer influence may be one reason why girls who start school at a younger age are less likely to be overweight, the authors suggest.
"Within any grade, younger girls may be exposed to relatively older friends, who are more careful about their weight and physical appearance," Zhang said in a journal news release.
In addition, girls who are young for their grade have earlier exposure to more detailed and sophisticated health and diet information at school and have the opportunity to participate in more advanced physical activity instruction as well.
The U.S. Centers for Disease Control and Prevention outlines how parents can help their children maintain a healthy weight.