Fig. 1

Process for selecting participants for this study. Eligible participants were recruited, stratified by body mass index, and subjected to frailty and brain volume analyses. *Participants with insufficient data quality for FreeSurfer analysis, including 17 individuals in whom an error occurred during the automated analysis process, 29 with extreme outliers in the estimated total intracranial volume, and 122 with extreme outliers in the volumes of at least five brain regions. BMI, body mass index; JPSC-AD, Japan Prospective Studies Collaboration for Aging and Dementia; n, number; T1WI, T1-weighted image.