Additional Study Information: The goal of this study is to better understand why some people have managed to lose weight and keep it off while others have not. We are recruiting people who have lost weight and kept it off as well as healthy non-dieters with overweight or obesity who are not trying to lose weight. Study participation involves computer tasks, brain imaging, and eating a lunch meal in the research center. Participation in the study is expected to involve up to 3 visits to the research center that will last from 2 to 4 hours per visit. Participants will be compensated up to $250 for their time.