Long-term obesity impacts brain morphology, functional connectivity and cognition in adults

Abstract

Although obesity has been implicated in brain and cognitive health, the effect of longitudinal obesity trajectories on brain and cognitive aging remains insufficiently understood. Here, using multifaceted obesity measurements from the UK Biobank, we identified five distinct obesity trajectories: low-stable, moderate-stable, high-stable, increasing and decreasing. We observed that individuals in the decreasing trajectory showed minimal adverse effects on brain structure and cognitive performance, compared with the low-stable trajectory (low obesity levels over time). By contrast, the increasing and moderate- and high-stable trajectories were associated with progressively greater impairments in brain morphology, functional connectivity and cognitive abilities. Specifically, adverse effects extended from fronto-mesolimbic regions in the increasing trajectory to parietal and temporal regions in the moderate-stable trajectory, culminating in widespread brain abnormalities in the high-stable group. These findings highlight the dynamic relationship between obesity evolution and brain-cognitive health, underscoring the clinical importance of long-term monitoring and management of obesity through a multifaceted approach. Using data from the UK Biobank, the authors conducted a longitudinal analysis to measure the effects of obesity on cortical thickness, brain functional connectivity and cognitive abilities in middle-aged and older adults.