Ketogenic Diet and Brain Response in Anorexia Nervosa

Inclusion Criteria: Weight Recovered Anorexia Nervosa (wrAN) * Age 18-45 years old * Male and Female sexes * All ethnic backgrounds * History of restricting-type anorexia nervosa (AN) according to DSM-5 criteria * Weight recovered with a body mass index \> 17.5 for at least one month at the time of study * Elevated eating disorder-relevant behaviors on the Eating Disorders Inventory-3 and the Eating Disorder Examination Questionnaire Healthy Control Group * Age 18-45 years old * Male and Female sexes * All ethnic backgrounds * Normal lifetime BMI according to CDC Exclusion Criteria: Weight Recovered Anorexia Nervosa (AN) * Current pregnancy or nursing (will have to agree to contraceptive measures if sexually active) * Lifetime history of bipolar I disorder or psychosis * Current substance abuse or dependence in the past 3 months * Psychotic illness/other organic brain syndromes, dementia, somatization disorders or conversion disorders * History of significant head trauma * Indication of intellectual disability or autism spectrum disorder Healthy Control Group * No lifetime psychiatric illness and in particular no eating disorder history * Not be taking medication, and will not have a first degree relative with an eating disorder. No subject in either group will have or be * mental retardation or pervasive developmental disorder * organic brain syndrome * dementia * psychotic disorder * bipolar disorder * somatic symptom * conversion disorder * current alcohol or substance use disorder * indication of major medical illness including a history of seizure disorder * pregnant or nursing at the time of the study * a history of traumatic brain injury. * diabetes mellitus or other metabolic disorders that could worsen on a ketogenic diet * intracranial or any other metal object within or near the head that cannot be safely removed, excluding the mouth * implanted neurostimulators, intracardiac lines, or heart disease