Intranasal Oxytocin and Food Intake in Obese Adolescents

Inclusion Criteria: 1. Proficient in English. 2. Pubertal or Post-Pubertal Females: 13 to \<18 years. 3. Pubertal or Post-Pubertal Males: 15 to \<20 years. 4. Girls must have a negative urine pregnancy test and post-menarchal girls must use an acceptable method of contraception, including abstinence, a barrier method (diaphragm or condom), Depo-Provera, or an oral contraceptive, for the duration of the study. 5. Currently obese (BMI \>95%ile for age/sex if age \< 18 years, BMI \> 30 kg/m2 age 18 - 20 years). In children, obesity is defined with respect to age- and sex based as greater than or equal to the 95th%ile1, whereas in adults, an absolute threshold is used. 6. Parental/guardian permission (informed consent) and if appropriate, child assent. Exclusion Criteria: 1. Diabetes mellitus requiring insulin or insulin secretagogue. (Laboratory values: HgbA1c ≥8.5%) 2. Cardiovascular condition, as defined as any of the following: i) abnormal blood pressure, defined as \<3%ile or \>97%ile for age, sex and height 3, for adult participants abnormal blood pressure is defined as Stage 2 hypertension (systolic BP \> 160 mm Hg or diastolic BP \> 100 mm Hg); ii) history of cardiac arrhythmia or arrhythmia detected on screening ECG; iii) history of heart failure and/or cardiomyopathy; iv) prolonged QTc interval (QTc \> 460 msec), and/or long QT syndrome phenotype and/or positive genotype for long QT syndrome pathogenic mutations. 3. Concurrent use of medications known to prolong QTc interval and pose high risk for Torsades de Pointes (TdP) according to the current information available (www.crediblemeds.org). Concomitant medications will be assessed by the Investigational Drug Service (IDS) pharmacist, in collaboration with the study cardiologist, if additional clarification is needed. In addition, we require that potential participants be on a stable dose for at least 2 months of any medication with the potential to alter cardiac rhythm to ensure the screening ECG reflects steady-state physiology. 4. Laboratory abnormalities that indicate abnormal sodium level, liver or renal disease, or anemia: Sodium - Outside Normal Range; Aspartate Aminotransferase (AST)/SGOT \> 3.0 X's Upper Limit of Normal (ULN); Alanine Aminotransferase (ALT)/SGPT \> 3.0 X's Upper Limit of Normal (ULN); Estimated Glomerular Filtration Rate (eGFR) \< 60 mL/min/1.73m2; Hemoglobin \< 10 g/dL 5. Seizure in the past 12 mos. 6. History of gastrectomy, gastric bypass, small or large bowel resection. 7. History of active substance abuse. 8. Current use of psychiatric medications. Current psychotic disorder and/or suicidality. 9. Other chronic medical conditions or medications likely to affect appetite or food intake. 10. Any investigational drug use within 30 days prior to enrollment. 11. Pregnant or lactating females. 12. Inability to take intranasal medication (e.g., recent injury) 13. Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures.