Inclusion Criteria: - Diagnosis of Bipolar Disorder (Type I or II), which is the primary focus of treatment - Ability to give informed consent - Currently ill (CGI-BP ≥ 3) - Age > 18 years and < 65 years - Overweight individuals (BMI > 25) Exclusion Criteria: - Unwilling/unable to comply with study procedures - Endorsed item, confirmed by patient's physician, on the PAR-Q - Euthymic (CGI-BP < 3) - Diagnosis of an eating disorder (e.g., anorexia nervosa, bulimia nervosa) in the past month - Diagnosis of substance dependence in the past month - Active suicidality (MADRS item 9 score > 4) - Pregnant (as analyzed by a urine pregnancy test) - Currently receiving another psychosocial treatment - Exercising regularly (i.e., 5 days per week for 30 min) - Neurologic disorder or history of head trauma - Contraindications to exercise or diet interventions (e.g., co-morbid nutritional and metabolic diseases, physical injuries)