Impaired cognitive functioning in overweight children and adolescents

The purpose of this review was to evaluate the evidence and summarize the hypotheses developed to explain the association between excess body weight status and impaired cognitive functioning among children. Consistent with observations from adults, well designed epidemiological investigations and clinical observations have linked cognitive deficiency with being overweight among the paediatric population. Lesions in the right hemisphere of the brain may exist among children with excess body weight, indicating that the adverse effects of being overweight on cognitive function plays a role as early as childhood, and cognitive impairments may occur in younger persons without the pathological cardiovascular changes typically associated with aging. A precise explanation for the association remains unclear. Delayed or absent myelination, as well as demyelination, of neurons caused by abnormal levels of "adipokines", and the detrimental effects of sleep apnoea have been postulated. The current review calls for sustained investigations to examine whether the associations during childhood result in larger deficits during adulthood, making persons more vulnerable to biologic perturbation, thus leading to decreased social functioning.