Academic Achievement, Obesity And Low Fitness In Japanese Adolescents

Abstract

It has been shown that aerobic capacity is related to reading and arithmetic ability in children and that acute exercise enhances cognitive function. Also, childhood obesity has been reported to have a negative influence on cognitive function and academic achievement. However, there is no reports examined the influence of physical and physiological factors such as childhood obesity and low physical fitness on academic achievement in Japanese schoolchildren. PURPOSE: The aim of this study was to investigate whether obesity and physical fitness are related to academic achievement in Japanese first-year junior high school students (equal to 7th graders in the U.S.). METHODS: The data of 421 students (male, n = 222; female, n = 199; age = 12.4 ± 0.4 yrs) in Hokkaido Prefecture were analyzed. Academic achievement was assessed by the total grade points of 8 school subjects (GP8; each subject was assigned 1 to 5 points) not including physical education. Comprehensive physical fitness was evaluated by the total score of 8 fitness tests including a 20-m shuttle run. Socioeconomic and behavioral confounders including mother’s education, household income and cram school utilization were used as covariates. RESULTS: The GP8 of students with a body mass index (BMI) over 25 was significantly lower than that of students with a BMI under 25 or under 18 (25.3 ± 5.5 vs. 28.7 ± 5.5 vs. 28.7 ± 6.1 points, respectively; p<0.05). Comprehensive physical fitness and 20-m shuttle run test scores were correlated with GP8 in male students (r = 0.352 and r = 0.361, respectively). In female students, only the 20-m shuttle run test score was correlated with GP8 (r =0.158). After adjusting for the confounders, comprehensive physical fitness score was found to be a significant factor for determinants of GP8 in male students (β = 0.327), but not in female students. Obesity status was a factor for GP8 in female students (β = -0.218), but not in male students. CONCLUSIONS: These results suggest that obesity and low physical fitness could have a negative effect on academic achievement in Japanese junior high school students.