Obesity, MorbidObesityGastroplastyGastric BypassBiliopancreatic DiversionBariatric SurgeryWeight LossAnastomosis, Roux-en-YBody Mass IndexLaparoscopyJejunoileal BypassAvitaminosisHalf-LifeObesity, AbdominalArea Under CurveSurgical StaplersPostoperative ComplicationsJejunumPediatric ObesityBody WeightStomachGastrectomyMetabolic Clearance RatePharmacokineticsLeptinBiological AvailabilityElephantiasisAdministration, OralIleumTreatment OutcomeAdipose TissueVitamin B DeficiencyPrader-Willi SyndromeInsulin ResistanceRisk FactorsInjections, IntravenousOverweightDiabetes Mellitus, Type 2PrevalenceDrug InteractionsFollow-Up StudiesEatingFatty LiverTime FactorsReceptors, LeptinMalabsorption SyndromesBlood GlucoseInsulinProspective StudiesComorbidityMetabolic Syndrome XInfusions, IntravenousCross-Over StudiesTissue DistributionDose-Response Relationship, DrugMethodsPostoperative CareChromatography, High Pressure LiquidDiabetes MellitusCohort StudiesDigestive System Surgical ProceduresRetrospective StudiesFood-Drug InteractionsUnited StatesAnti-Obesity AgentsDietLiverAdiposityDrug Administration ScheduleWaist CircumferenceGenotypeDietary FatsWeight GainCross-Sectional StudiesEnergy Metabolism