Neuropathy measures completed at baseline and 2 years (obese subjects only) include: definite clinical neuropathy will be established using Toronto consensus guidelines based upon neurologic exam, nerve conduction studies, Michigan Neuropathy-Specific Instrument, Utah Early Neuropathy Scale, balance and hip strength measures, cognitive testing (computerized cognitive screening to determine how obesity affects the central nervous system) (also done at time 12 +/- 4 weeks and 52 +/- 4 weeks post-baseline visit), neurothesiometer testing, skin biopsy to determine nerve fiber density, Quantitative Sudomotor Axon Reflex Test (QSART) to measures the autonomic nerves that control sweating, heart rate variability/cardiac autonomic neuropathy testing to assess for autonomic neuropathy, quantitative sensory testing to assess for small fiber neuropathy, Sudoscan to assess sweat gland function, and the following questionnaires: Neuropathy Quality of Life, McGill Pain, Autonomic symptoms profile.