This study will be the first clinical trial to examine the impact of two different weight loss interventions on novel mechanisms that promote obesity and impede its successful treatment, including cognitive function and self-regulatory factors. The results will provide important data about how impaired cognitive function and/or self-regulation promote obesity and how different weight loss treatments may differentially impact these factors; this information will be used to identify promising cognitive and self-regulatory treatment targets for preventing further obesity development and for maintaining weight loss.