Bariatric surgery can result in substantial weight loss and significant metabolic improvements. Therefore, clinicians should be prepared to taper treatments for weight-related chronic metabolic diseases. For patients with type 2 diabetes, early and dramatic improvements in glucose homeostasis require anticipatory management. This includes insulin dose reductions, discontinuation of certain oral agents, and close monitoring. Antihypertensive medications should be adjusted to avoid hypotension. Even after postoperative improvements in dyslipidemia, some patients will continue to meet criteria for statin therapy. While many obesity-related diseases will improve, clinicians should also be prepared to manage postoperative medical and nutritional complications. Micronutrient deficiencies are common, and professional guidelines provide recommendations for preoperative screening, universal postoperative supplementation, micronutrient monitoring, and repletion strategies. Changes in gastrointestinal physiology may result in dumping syndrome, and patients may report early gastrointestinal and vasomotor symptoms after eating. In contrast, post-gastric bypass hypoglycemia is a rare complication of malabsorptive procedures, resulting in insulin-mediated hypoglycemia after carbohydrate-containing meals. Rapid weight loss may increase risk of cholelithiasis, which can be mitigated by ursodiol. After malabsorptive procedures, enteric hyperoxaluria and other factors may result in nephrolithiasis, which can be addressed with hydration, dietary interventions, and calcium. All bariatric surgeries induce a high bone turnover state, with declining bone mineral density (BMD) and increased fracture risk. Appropriate strategies include adequate calcium and vitamin D supplementation and age-appropriate BMD screening. Long-term strategies to prevent weight regain include adherence to healthy lifestyle practices, identification and avoidance of medications that promote weight gain, and prescribing weight-loss medications. In summary, given dramatic physiologic changes with bariatric surgery, clinicians should be prepared to taper treatments for chronic metabolic diseases, to manage postoperative medical and nutritional complications, and to identify and manage risk for weight regain.