Adipose Tissue Blood Flow in Aging Humans

The goal of this basic science clinical trial is to understand whether adipose tissue blood flow changes between younger and older healthy adults. The main question\[s\] it aims to answer are: * Is basal and nutrient responsive adipose tissue blood flow (ATBF) different between younger and older adults * What molecular and systemic signatures related to adipose tissue blood flow are altered between these two groups. Participants will undergo measurements of adipose tissue blood flow using the xenon washout technique, undergo 2 abdominal subcutaneous adipose tissue biopsies, and drink a sugary drink.