Ketogenic and Nutritional Interventions for First Episode Bipolar Disorder

Inclusion Criteria: * Between the ages of 18 and 45. * Ability to adhere to study diets. * Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) diagnosis of bipolar I disorder or schizoaffective disorder with onset of illness in the last 7 years. * Must have a stable psychiatric disorder with no change in psychiatric medications within the past 2 weeks of screening * Must not be expected to require addition of any new psychiatric medications during the 12-week duration of the study. Exclusion Criteria: * Unable to sign informed consent * Contraindication to magnetic resonance (MR) scan (including claustrophobia) * Unstable medical illness (including cardiovascular, hepatic, renal, respiratory, endocrine, neurological, or hematological disease) * Current DSM-5 substance use disorder * Currently pregnant, nursing, or of childbearing potential and not using a medically accepted means of contraception * Have a body weight of over 350 lbs or a body mass index (BMI) \<20 * Score above 15 on the Young Mania Rating Scale (YMRS) * History of significant head injury * Current cancer diagnosis * Current diagnosis of type 1 or type 2 Diabetes Mellitus * History of gastric bypass surgery or any weight loss surgery * Concomitant treatment with Propofol * Familial hypercholesterolemia