Study 2 will be a double-blind parallel study and volunteers will be randomized to receive either active TDCS or no stimulation (sham) to the left DLPFC. During a 4-week outpatient period, both groups will be asked to consume a diet that is a 25% reduction from their calculated weight maintenance calories and come to the Unit 3x per week for stimulation sessions. The primary outcome measurements will be total food intake during 3-d of ad libitum intake from a computerized vending machine system, and weight loss during a 4-week outpatient period. In study 1 we will also examine appetitive hormones and behavioral factors, which might also mediate potential changes in food intake and weight loss following TDCS to the left DLPFC. Positive findings from this study could demonstrate the utility of a novel and safe treatment for severe obesity. Future studies could include longer clinical trials of TDCS with extended follow-up durations.