Patients who had either clinically severe obesity (morbid obesity, MO, or super obesity, SO) underwent a primary Roux-en-Y gastric bypass. The ones that were subsequently revised ending up with an optimized malabsorptive distal gastric bypass were identified from our prospectively maintained bariatric database and included in this study. Specific metabolic and nutritional complications after RYGB surgery were defined according to standard definitions based on signs, symptoms, and laboratory measurements.