This study is designed to determine whether obese, normal weight, and successful weight loss maintainers differ in their food choice decision-making and/or executive function, and whether participation in a behavioral weight loss program leads to neural and/or behavioral changes. The investigators will examine behavioral performance on several tasks involving decision-making and self-control in conjunction with brain imaging data acquired during a food-choice decision-making task. Participants enrolled in the behavioral weight loss program will also be assessed following the treatment.