To evaluate the role of intentional weight loss on physical and cognitive function, the investigators propose an ancillary study to the on-going Look AHEAD (Action for Health in Diabetes) trial. Look AHEAD is a multi-center, randomized clinical trial to examine the effects of a 4-year lifestyle intervention designed to achieve and maintain weight loss through decreased caloric intake and exercise in overweight or obese men and women aged 45-74 years with type 2 diabetes. The investigators propose to add validated and well-established measures of physical and cognitive performance to the year 8 follow-up visit - during the trial's weight maintenance phase - in ~1000 participants at 4 of the 16 Look AHEAD field sites (Colorado, Memphis, Pennington and Pittsburgh).