Restricted access dataset used for the study "Diurnal oscillations of MRI metrics in human brains". Contains subject-level data within the following files: whole_brain_data.csv - average of each MRI metric across the relevant atlas for each time point. processed_ROI_data.csv - average of each MRI metric within each atlas ROI for each time point. whole_brain_techvar_data.csv - average of each MRI metric across the relevant atlas for each time point and back-to-back replicate. weights_kg.csv - body weight at each time point. actigraphy_3day.csv - steps registered by the FitBit device each minute for the 3 days of observation. actigraphy_sleep.csv - sleep intervals registered by the FitBit device during the 3 days of observation.