The Relationship between Middle Childhood Body Mass Index, Stress, Physical Activity, and Academic Achievement

Johnna Kellie Fox Thompson, Gardner-Webb


This study investigated the relationships between body mass index (BMI), stress, physical activity, and academic achievement among middle childhood students. The researcher used a mixed-methods research design. The general population for this study was composed of students at one of the district's intermediate schools.

The sample included 680 students from a small, suburban intermediate school (Grades 4 [N=231], 5 [N=218], and 6 [N=231], 337 males and 343 females). The school is located in a suburban area near a large city in the southeast. The students from the school described themselves as White (71%), African American (16%), Hispanic (7%), Asian/Pacific Islander (2%), Multi-Racial (4%), Economically Disadvantaged (39%), Limited English Proficient (2%), Students with Disabilities (17%), and Academically Gifted (26%).

Participants were weighed and measured to establish valid BMI. The physical education teacher took all of the measurements. Academic achievement was obtained using district benchmark test results and report card grades. Tardies, in-school suspensions, and out-of-school suspensions for the first quarter of the 2012-2013 school year were also used. Reading and math grades for the first 9-week grading period were collected by the school data manager. District benchmark data were collected by the assistant principal. Data from physical education classes measuring student stress and physical activity were collected and coded with each student's number by the physical education teacher. Data collection included interviews with teachers to determine teacher perceptions regarding childhood obesity, stress, physical activity, and the relationship these have with academic performance.

Based on BMI classifications for age and sex, nearly 40% were either classified as underweight (n=39), overweight (n=86), or obese (n=118). A significant correlation existed for academic achievement between BMI and language arts grades, math benchmarks, and science benchmarks (for fifth grade only). There was also a significant correlation between BMI and stress levels for students in fourth, fifth, and sixth grades. No other significant differences were discovered between BMI, academic performance, and physical activity levels.