Above average increases in body fat from 9 to 15 years of age had a negative impact on academic performance, independent of physical activity

• Published in: Acta Paediatrica Vol. 108; no. 2; pp. 347 - 353
• Main Authors: Sævarsson, Elvar Smari, Gudmundsdottir, Sigridur Lara, Kantomaa, Marko, Arngrimsson, Sigurbjorn A., Sveinsson, Thorarinn, Skulason, Sigurgrimur, Johannsson, Erlingur
• Format: Journal Article
• Language: English
• Published: Norway Wiley Subscription Services, Inc 01.02.2019
• Subjects: Academic achievement; Academic Performance; Accelerometers; Adiposity; Adolescent; Adolescents; Body composition; Body fat; Body mass; Body mass index; Cardiorespiratory Fitness; Child; Children; Exercise; Female; Growth models; Humans; Language; Longitudinal Studies; Male; Physical activity; Children; Adiposity; Physical activity; Body composition; Academic performance
• ISSN: 0803-5253; 1651-2227
• DOI: 10.1111/apa.14459

Aim The associations between body fat levels and physical activity with academic performance are inconclusive and were explored using longitudinal data. Methods We enrolled 134/242 adolescents aged 15, who were studied at the age of nine and agreed to be followed up from April to May 2015 for the Health behaviours of Icelandic youth study. Accelerometers measured physical activity, body mass indexes (BMI) were calculated and dual‐energy X‐ray absorptiometry scans assessed the participants’ body composition at nine and 15. Their language and maths skills were compared to a growth model that estimated the academic performances of children born in 1999. Results Higher than normal body fat levels between the ages of nine and 15 were negatively associated with maths performance, but the same association was not found for Icelandic language studies. These were Pearson's r = −0.24 (p = 0.01) for BMI and Pearson's r = −0.34 (p = 0.01) for the percentage of body fat. No associations were found with changes in physical activity. Conclusion Children who put on more body fat than normal between the ages of nine and 15 had an increased risk of adverse academic performance that was independent of changes in physical activity.