During the screening visit at the research laboratory, subjects will complete informed consent, a health history questionnaire, an MRI Safety screening form, and a physical activity questionnaire. Height, weight, blood pressure, and waist and hip circumference will also be taken. Additionally, a venous blood sample will be drawn for glucose and lipid testing to determine eligibility. If the screening visit reveals that there is an abnormality or contraindication to participation, which is covered or not covered in the summarized exclusion criteria, the potential subject will not be allowed to participate. As a summary, subjects will experience the following activities during the in-lab screening visit: