Weight Gain Prevention in Adolescents and Young Adults

Inclusion Criteria:

* Age 18 to M 25 at screening
* BMI \>/= 25 to \< 30 kg/m\^2
* Family history of obesity defined as one biological parent with severe obesity (BMI \>/= 35) and/or two biological parents with obesity (BMI \>/=30). Parental obesity status will be confirmed by obtaining a release of information to review and electronic health record.

Exclusion Criteria:

* Tanner stage 1-4
* Diabetes (type 1 or 2)
* Current or recent (\<6 months prior to screening) use of anti-obesity medication(s) or other weight-altering medication(s) (e.g. atypical anti-psychotics, attention deficit hyperactivity disorder (ADHD) stimulant)
* Previous bariatric surgery
* Current or recent (\<6 months prior to screening) use of medication(s) to treat insulin resistance
* Recent initiation (\<3 months prior to screening) of anti-hypertensive or lipid medication(s)
* History of glaucoma
* Current or recent (\<14 days prior to screening) use of monoamine oxidase inhibitor
* Known hypersensitivity to sympathomimetic amines
* History of treatment with growth hormone
* Patient Health Questionnaire-9 (PHQ-9) score of \>/= 15 at screening
* Eating disorder symptoms within 6 months and/or any past medical diagnosis of eating disorder
* Major psychiatric disorder
* Unstable clinically-diagnosed depression
* History of suicide attempt
* Suicidal ideation of type 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) at any time during the study
* Current pregnancy or breastfeeding
* Plans to become pregnant
* If sexually active, refusal to use 2 forms of birth control
* Tobacco use
* Alanine transaminase (ALT) or aspartate transaminase (AST) \>/= 2.5 times the upper limit of normal
* Bicarbonate 18 mmol/L
* Creatinine \> 1.2 mg/dL
* Creatinine clearance \<50 mL/min (Schwartz formula)
* History of seizures
* Uncontrolled hypertension
* History of structural heart defect
* History of clinically significant arrhythmia
* Diagnosed monogenic obesity
* History of cholelithiasis
* History of nephrolithiasis
* Hyperthyroidism
* Untreated thyroid disorder