The project is the largest study to date to investigate the long-term relationships between bariatric surgery and durable improvements in body weight, hypertension, and renal disease, as well as its association with major operative complications and long-term survival. These outcomes will be compared to a population-based cohort of severely obese patients who have not had weight loss surgery and investigate demographic and clinical characteristics (e.g., age, gender, race/ethnicity, bariatric procedure type, T2DM severity, and other comorbid medical and mental health conditions and their treatments) that may be associated with beneficial and adverse outcomes of surgery.