Bariatric (weight loss) surgery is the most effective treatment for extreme obesity, but surgery does not treat underlying psychological and behavioural issues. Currently, psychotherapy ("talk therapy") for eating problems is not routinely offered with surgery, and many people start to regain weight one year later. Objective: This study will examine if adding a convenient and accessible psychotherapy by phone one year after surgery will lead to increased weight loss two years after surgery. Primary Hypothesis: Relative to the Control group (who will get routine care), the group of individuals who get psychotherapy will have lower weights 2 years after surgery. Secondary Hypotheses: Relative to the Control group, the psychotherapy group will report significantly less maladaptive eating behaviours and medical burden, and significantly greater quality of life. Method: Participants recruited from the Bariatric Surgery Programs at Toronto Western Hospital will be randomly assigned to 1 of 2 groups: 1) Control (Usual Standard of Care) or 2) Tele-CBT (a 7-session telephone-based cognitive behavioural therapy [a type of "talk therapy"] intervention focused on developing coping skills to improve maladaptive thoughts, emotions, and eating behaviours, specifically designed for bariatric surgery patients, delivered 1 year post-surgery). They will have their weight measured and will complete measures of eating behaviour and quality of life prior to the intervention, and again at several time points extending to 2 years post-surgery. Implications: If Telephone-Cognitive Behavioural Therapy (CBT) is found to improve bariatric surgery outcomes, it could become the standard of care in Canadian bariatric surgery programs and beyond, and be routinely offered to patients who cannot feasibly attend CBT sessions due to physical or practical barriers.