Common mechanisms in aging and obesity are hypothesized to increase susceptibility to neurodegeneration, however direct evidence in support of this hypothesis is lacking. We therefore performed a cross-sectional analysis of MRI-based brain structure on a population-based cohort of healthy adults. Study participants were originally part of the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) and included 527 individuals aged 20 – 87 years. Cortical reconstruction techniques were used to generate measures of whole brain cerebral white matter volume, cortical thickness and surface area.