The Effect of Increasing BMI on Reaction Time, Sustained Attention and Working Memory in Children and Adolescents

This study aims to investigate the effect of increasing body mass index (BMI) on cognitive functions such as reaction time, sustained attention, and visuospatial working memory in children and adolescents. The research method is causal-comparative, and is a basic study in terms of purpose. The statistical population of the present study consists of all high school students (12–15 years old) in Tehran in 2019, among which 75 students (36 girls and 39 boys) were selected by convenience sampling method and classified into three groups of obese, overweight and normal weight based on BMI. All participants completed the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess cognitive performance and BMI was also measured. Data were analyzed using SPSS software (version 26). The results of multivariate analysis of variance showed that obese students performed worse on the tests of reaction time and visuospatial working memory than the normal and overweight groups, and their difference is significant (p 0.01). Accordingly, one can say that increasing fat and BMI levels lead to a decrease in some cognitive functions and this may delay or decrease the development of students’ academic and social skills.