The overall goal of this study is to use magnetic resonance imaging (MRI) techniques to determine fat content within skeletal muscle, thereby continuing the research relating patterns of fat distribution to substrate metabolism and insulin resistance. The hypothesis to be tested is that the fat content in skeletal muscle is increased in obese individuals, and that this is also related to insulin resistance and Type II diabetes. One specific aim of this protocol is to use fat/water suppression MRI technique to assess lipid content within skeletal muscle and relate these data assessments of muscle fat content based on the computed tomography (CT) method. Another specific aim is to use echo planar imaging to obtain a T1 map of skeletal muscle and determine whether this provides a non invasive means to assess skeletal muscle Type I fiber type distribution (and skeletal muscle oxidative enzyme capacity). The third specific aim is to examine how obesity and Type II diabetes influence these MRI parameters, and the extent to which fat within muscle is associated with insulin resistance.