The association between body mass index and academic performance

To examine the relation between body mass index (BMI) and the academic performance of students from Taif city, Kingdom of Saudi Arabia (KSA) using the grade point average (GPA). Method: A cross-sectional study that includes students from intermediate and high schools located in Taif city, KSA between April 2014 and June 2015. Height and weight were measured and BMI calculated. Related risk factors including dietary habits, activity, parent's education, sleeping pattern, and smoking were recorded.  Result: A total of 14 schools included 424 students. 24.5% were either overweight or obese. The mean age was 15.44 year, 74.8% of the students were male, 53.8% were high school students, and 83.7% attended public schools. The mean overall GPA was 82.44% and the mean GPA for science subjects was 70.91%. No statically significant difference in the BMI was found between those who achieved greater than 90% of the overall grade compared with those who achieved less than 90%. Post hoc 1-way-analysis of variance showed that obese students were performing worse in physics than normal weight peers (p=0.049). Students who achieved greater than 90% overall grade are more likely to attend private school (p less than 0.05), live with their parents (p=0.013), having educated parents (p=0.037), getting optimal sleep (p less than 0.05), and they rarely eat their food outside their home (p less than 0.05).  Conclusion: There was no correlation between the BMI and school performance, except in physics results where obese students perform worse than normal-weight students.