The French region most affected by obesity is Upper Normandy, with a prevalence rate of 13.8% across all age groups in 2000, compared to the French average of 9.6%. The Regional Health Observatory (ORS) of Upper Normandy, in collaboration with the Rouen Academy’s Office of Education, conducted a study on the eating habits of middle school students in Upper Normandy. This survey collected data on the students’ weight and height. This article presents the results regarding the body mass index of middle school students in Upper Normandy.