Obese adolescent girls may have more trouble in school than their peers who are at a healthy weight.

A research team looked at the "association between obesity and academic attainment in adolescence," a University of Strathclyde news release reported.

The team found girls who were obese as measured by their BMI had lower academic attainment at the ages of 11, 13, and 16, than their peers who had a healthy BMI. The study took into account other mediating factors that could affect the results, but found this did not make a difference in the results.

Academic attainment rates in subjects such as English, math, and science were found to be the equivalent of a "D" grade as opposed to a "C" in the obese adolescents.

The study looked at data from 6,000 children who participated in the Avon Longitudinal Study of Parents and Children (ALSPAC) and assessed their test scores. Of these study subjects 71.4 percent were of a healthy weight, 13.3 percent were overweight, and 15.3 percent were obese.

"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," doctor Josie Booth, of the School of Psychology at the University of Dundee, said in the news release.

The difference in academic attainment between obese adolescent boys and those of a healthy weight were not found to be significant.

"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," Principle Investigator of the study and University of Strathclyde Professor of Physical Activity and Public Health Science, John Reilly, said in the news release.