Researchers examine how obesity influence grades in primary school

Children who are extremely overweight achieve lower math grades and attend German upper secondary school (Gymnasium) less frequently, is shown by a study, undertaken by the WZB Berlin Social Science Center (WZB). For the first time, it has been proved  that obesity regardless of the students social background influences school performance. Previously, it was only known that people with lower education had a tendency  to suffer from weight issues. In Germany 15 percent of children and young people between the ages of  3 to 17 are overweight, and about 6 percent are obese.

In their study, WZB's researchers Marcel Helbig and Stefanie Jähnen examine how weight and obesity influence  grades in mathematics and German in primary school as well as the student's transition to upper secondary school, the gymnasium.

While overweight children do not perform worse in math, obese girls and boys achieve a "good" or "very good" math grade less frequently. The likelihood of getting grade 1 or 2 is 10 or 11 percent points lower compared to children of normal weight. Furthermore, because obese girls are bullied more often, they show lower self-confidence which leads to more behavior problems. For boys no "bully effect" was found. However obese boys also suffer from lower self-confidence, which partly explains the lower math grades. The influence of obesity on math grades is not effected by whether a child is healthy, to what extent they exercise or participate in sports or how much TV they watch.

Obese girls and boys attend upper secondary school (Gymnasium) less frequently. The same effect is reported for overweight boys. Whether lower math grades or other factors cause this outcome has not been fully clarified in the study. Possibly, teachers perceive obese children as  less competent and recommend them less frequently for gymnasium, or perhaps parents have lower confidence in those children and send them to a upper secondary school less often.

The study used data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), conducted by the Robert Koch Institute as well as data from Mikrozensus 2009, a representative individual and household survey.