 Patients will fast for at least 8 hours prior to the first study visit. At this visit, blood will be drawn and body measurements will be taken. Patients will then discontinue their ART. Patients taking nonnucleoside reverse transcriptase inhibitors NNRTIs will stop taking NNRTIs 48 hours before withdrawing their other ART drugs. Study visits will occur every 4 to 8 weeks for the first year, then every 12 weeks for the second year. Blood will be taken at most visits, and patients will be asked to fast for at least 8 hours prior to Week 12 and 24 visits and again every 6 months. Patients who reinitiate ART for any reason will be registered to Step 2 and followed for 24 weeks. 