PET imaging is a relatively non-invasive way to obtain a "metabolic picture" of body organs and has been used successfully to study brain, heart and more recently skeletal muscle. In this research study, we will use PET, with three radioactive tracers (markers), to study skeletal muscle glucose transport in individuals with type 2 diabetes mellitus (type 2 DM) and in non-diabetic individuals who are either normal weight or overweight/obese