Metabolic risk of obesity surgery and long-term follow-up

Protein-calorie deprivation occurs after weight reduction operations and creates a potential for micronutrient deficiency syndromes. Whether clinical deficiency occurs depends primarily on the nature of the operation carried out. Current procedures include those that mainly diminish intake and those that shunt either food or digestive enzymes to minimize the absorption of ingested food. The metabolic price that some patients pay postoperatively makes the choice of operation and the quality of follow-up critical to the patient's well-being. Restrictive operations (gastroplasty) are devoid of long-term metabolic complications. Gastric bypass patients rarely have deficiency syndromes but often develop micronutrient deficiencies. Malabsorptive procedures carry the highest risk and malnutrition, with multiple micronutrient deficiencies, may supervene despite close medical follow-up.