Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing (GESTALT)

Background: \- Biomarkers are substances in people's blood and tissues. They help researchers understand diseases and signs of aging. Scientists want to do more research on biomarkers to find ways to improve quality of life in old age. Objective: \- To learn more about biomarkers and their relationship to aging. Eligibility: \- Adults at least 20 years old who weigh at least 110 pounds and have a body mass index below 30. They must agree that their genetic samples can be collected, studied, and stored. Design: * Participants will be screened with medical history, physical exam, EKG and blood and urine tests. * Participants will have 3-day visits. They will return every 2 years. * All visits include: * Blood and urine collection * Physical performance tests * Health questionnaires * Memory and problem-solving tests * Magnetic Resonance Imaging (MRI) and Computerized Tomography (CT) scans. * Muscle metabolism/ exercise tests * Taste strips * Muscle and/or skin biopsies/ red light therapy * Retinal imaging/ eye tracking * Sleep study * ODD visits also include: * Cytapheresis * Bone marrow aspirate * EVEN visits also include: * Hyperglycemic CLAMP * Lumbar Puncture (LP) * Continuous Glucose Monitor (CGM)