Inclusion Criteria:
* Be in the age range ≥18 years of age and \<65 years of age.
* Have had laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy
* Approximately ten months post-surgery
* Experienced regular loss of control eating about six months after bariatric surgery, and were considered treatment non-responders to a four-month treatment trial of medication and/or BWL
* Be an otherwise healthy subject without uncontrolled medical problems, as determined by the study physician and medical co-investigators (physical examination, laboratory studies).
* Read, comprehend, and write English at a sufficient level to complete study-related materials.
* Provide a signed and dated written informed consent prior to study participation.
* Be available for participation in the study for up to 15 months (3-month treatment plus 12-month follow up).
Exclusion Criteria:
* Has a predisposition to seizures (e.g., subject with a history or evidence of seizure disorder, febrile seizures during childhood, brain tumor, cerebrovascular disease, or significant head trauma; has a family history of idiopathic seizure disorder or is currently being treated with medications or treatment regimens that lower seizure threshold).
* Has a history of anorexia nervosa or history of bulimia nervosa.
* Is currently using other medications for weight loss.
* Has a co-existing psychiatric condition that requires hospitalization or more intensive treatment (such as bipolar mood disorders, psychotic illnesses, or severe depression)
* Has untreated hypertension with a seated systolic blood pressure \> 160 mmHg, diastolic blood pressure \> 100 mmHg, or heart rate \> 100 beats/minute.
* Has a history of congenital heart disease, cardiovascular disease, cardiac arrhythmias requiring medication, or a history of cerebrovascular pathology including stroke.
* Has current uncontrolled hypertension.
* Has current uncontrolled Type I or Type II diabetes mellitus.
* Has untreated hypothyroidism with a TSH \> 1.5 times the upper limit of normal for the test laboratory with repeat value that also exceeds this limit.
* Has gallbladder disease.
* Has a history of severe renal, hepatic, neurological, chronic pulmonary disease, or any other unstable medical disorder.
* Is currently in active treatment for eating or weight loss.
* Is currently participating in another clinical study in which the subject is or will be exposed to an investigational or a non-investigational drug or device.
* Is breast-feeding or is pregnant or is not using a reliable form of birth control.
* Reports active suicidal or homicidal ideation.
* Previous history of problems with LDX or other stimulants.
* Has a history of allergy or sensitivity to LDX or other stimulant medications.
* Current medication contraindicated with study medication.
* Any current psychostimulant use or any medication for ADHD.
* History or current alcohol or substance use disorder (smoking will not be exclusionary)
* Is currently taking MAOI medication, SSRI medication, or strong inhibitors of CYP2D6
