Impact of ectopic fat on brain structure and cognitive function: A systematic review and meta-analysis from observational studies

•This meta-analysis aimed to assess the effect of ectopic fat on brain structure and cognitive function.•For participants with ectopic fat, the decrease of total brain volume was observed.•More specifically, posterior cingulate cortex volume, semioval center volume and sensorimotor cortex volumes were reduced.•In addition, the increase of lateral ventricle volume, was observed in individuals with ectopic fat.•Ectopic fat has a detrimental effect on cognitive function, providing an increased risk of developing cognitive impairment, whereas but subcutaneous fat served a protective role against cognitive decline.