RecruitingDiagnostic testUpper Body Subcutaneous Exosome Release in Response to a Meal in ObesityThe purpose of this study is to understand the specific outflow and difference between normal weight and volunteers with obesity of upper body subcutaneous adipose tissue in response to a mixed meal challenge by site specific cannulation of the superior epigastric vein. We will characterize the exosome signatures in response to a meal and compare to the exosome signature of arterialized venous plasma samples.