Obesity in adolescent girls is associated with lower academic attainment levels throughout their teenage years, a new study has shown.
The research conducted by the Universities of Strathclyde, Dundee, Georgia and Bristol is the most comprehensive study yet carried out into the association between obesity and academic attainment in adolescence. The results are published in the International Journal of Obesity.
The results showed that girls who were obese, as measured by BMI (body mass index) at age 11 had lower academic attainment at 11, 13 and 16 years when compared to those of a healthy weight. The study took into account possible mediating factors but found that these did not affect the overall results.
Attainment in the core subjects of English, Maths and Science for obese girls was lower by an amount equivalent to a D instead of a C, which was the average in the sample.
Associations between obesity and academic attainment were less clear in boys.
University of Strathclyde Professor of Physical Activity and Public Health Science, John Reilly - the Principal Investigator of the study - said: "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."
Dr 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 study examined data from almost 6000 children from the Avon Longitudinal Study of Parents and Children (ALSPAC), including academic attainment assessed by national tests at 11, 13 and 16 years and weight status. 71.4% were healthy weight (1935 male, 2325 female), 13.3% overweight (372 male, 420 female) and 15.3% obese (448 male, 466 female).
The researchers took into account potentially distorting factors such as socio-economic deprivation, mental health, IQ and age of menarche (onset of the menstrual cycle) but found these did not change the relationship between obesity and academic attainment.