TUESDAY, March 11, 2014 (HealthDay News) -- Besides the well-known problems associated with being overweight at a young age, a new study suggests that obese teen girls tend to do worse in school than those with a healthy weight.
Researchers analyzed data from nearly 6,000 children in the United Kingdom and found that girls who were obese at age 11 had lower academic scores at ages 11, 13 and 16 than those with a normal weight.
The overall average grade in English, math and science was a C, but the average grade among obese girls was a D. The link between obesity and school grades was less clear in boys, according to the study, which was published March 11 in the International Journal of Obesity.
The investigators, from the University of Strathclyde, the University of Dundee and elsewhere, took into account other possible factors -- such as mental health, IQ, social and economic status, and the start of the menstrual cycle. But they found that those factors did not affect the link between obesity and school performance in girls.
Although the study found an association between weight and school grades in this group of girls, it did not prove cause-and-effect.
"Further work is needed to understand why obesity is negatively related to academic attainment. But it is clear that teenagers, parents and policymakers in education and public health should be aware of the lifelong educational and economic impact of obesity," principal investigator John Reilly, a professor of physical activity and public health science at the University of Strathclyde, said in a university news release.
In addition, researcher Josie Booth, of the school of psychology at the University of Dundee, said: "There is a clear pattern which shows that girls who are in the obese range are performing more poorly than their counterparts in the healthy weight range throughout their teenage years."
The American Academy of Pediatrics explains obesity's impact on teen health.