WASHINGTON - New evidence shows that obesity can hurt the grades teen girls earn in school.
Researchers in the UK compared the academic performance of 6,000 teens and found a grade gap linked to weight among the girls.
Those in the study who were classified as clinically obese - those who are dangerously over weight -- scored worse on standardized national tests than their counterparts with a healthy weight.
The tests were conducted at ages 11, 13 and 16 in English, math and science. And the researchers say the results were remarkably consistent -- even when accounting for mitigating factors like family income, mental health and IQ.
They say the difference between the obese girls and those of normal weight amounted to one full grade on a test -- a D instead of a C, for example.
The authors of the study say it shows a clear pattern among teen girls. But they say further research is needed to find exactly why obesity has such a negative impact on academic achievement.
The research team from the Universities of Strathclyde, Dundee, Georgia and Bristol says the link between obesity and school performance is far less clear among teen boys.
Their findings were published in the International Journal of Obesity.