The Differential Relationships Between Physical Activity and Adiposity with Cognitive Function in Preadolescent Children.

Abstract

PURPOSE: To identify the effects of adiposity and a physical activity (PA) intervention on cognitive and neuroelectric indices of inhibitory control in preadolescent children. METHODS: Children were randomly assigned to either a 9-month afterschool physical activity (PA) or a wait-list control (CON) group. Children completed a task that manipulated inhibitory control at pre- and post-test while measures of task performance and the P3-event related potential (ERP) were assessed. Children were further grouped according to weight category. 76 children with obesity (39 PA; 37 CON) completed testing. A sample of normal weight children (NW) (n=76) were matched to the sample of children with obesity based on treatment allocation and demographic variables of age, sex, IQ, SES, and fat-free VO2max. Changes in adiposity measures included whole body percent fat (%Fat), subcutaneous abdominal adipose tissue (SAAT), and visceral adipose tissue (VAT). The influence of physical activity and adiposity on task performance and brain function was examined. RESULTS: Children in the PA group decreased %Fat from pre- to post-test (p=.011); an effect not observed in the CON group. Children in the CON group gained SAAT and VAT from pre- to post-test (p’s≤0.001), whereas children in the PA group did not. The PA group showed larger P3 amplitude from pre- to post-test (p=.026); an effect not seen in the CON group. P3 amplitude did not differ between groups at pre-test for children with obesity; however, the PA group demonstrated larger P3 amplitude compared to the CON group at post-test (p=.006). Children with obesity in the CON group had smaller P3 amplitude at post-test compared to pre-test (p=.003), an effect not seen in NW children. Results suggest that physically inactive children with obesity have increased adiposity and smaller P3 amplitude over 9 months. Furthermore, results suggest that a PA intervention may be particularly beneficial for children with obesity, as they showed increased P3 amplitude from pre- to post-test. CONCLUSION: PA is beneficial for brain function in pre-adolescent children, especially in those with obesity. Given that childhood obesity is a public health concern with an array of health complications, these results have important implications for the physical and cognitive health of children.