A Contemporary Perspective on Long-Term Complications of Bariatric Surgery

Bariatric (metabolic) surgery results in durable weight loss and metabolic remission, but long-term safety is underappreciated. This narrative review synthesizes contemporary evidence on late complications across procedures, including nutritional and mineral deficiencies, sarcopenia, bone health disorders, dumping syndrome, nephrolithiasis, and mental health outcomes (depression, anxiety, substance use, and suicidality). Risks concentrate after malabsorptive operations, yet restrictive procedures are not exempt. We outline mechanisms (malabsorption, hormonal and bile-acid signaling, microbiota remodeling, and mitochondrial stress), highlight procedure-specific patterns, and summarize practical follow-up priorities spanning nutrition, bone, renal, and psychosocial domains. A structured checklist is proposed to operationalize multidisciplinary surveillance and early intervention. Shifting focus from technical success to lifelong care is essential to convert surgical weight loss into sustained gains in function and quality of life.