Published online Nov 15, 2017. doi: 10.4239/wjd.v8.i11.464
Peer-review started: June 13, 2017
First decision: July 11, 2017
Revised: August 11, 2017
Accepted: September 4, 2017
Article in press: September 5, 2017
Published online: November 15, 2017
Bariatric surgery is recognized as a highly effective therapy for obesity since it accomplishes sustained weight loss, reduction of obesity-related comorbidities and mortality, and improvement of quality of life. Overall, bariatric surgery is associated with a 42% reduction of the cardiovascular risk and 30% reduction of all-cause mortality. This review focuses on some nutritional consequences that can occur in bariatric patients that could potentially hinder the clinical benefits of this therapeutic option. All bariatric procedures, to variable degrees, alter the anatomy and physiology of the gastrointestinal tract; this alteration makes these patients more susceptible to developing nutritional complications, namely, deficiencies of macro- and micro-nutrients, which could lead to disabling diseases such as anemia, osteoporosis, protein malnutrition. Of note is the evidence that most obese patients present a number of nutritional deficits already prior to surgery, the most important being vitamin D and iron deficiencies. This finding prompts the need for a complete nutritional assessment and, eventually, an adequate correction of pre-existing deficits before surgery. Another critical issue that follows bariatric surgery is post-operative weight regain, which is commonly associated with the relapse of obesity-related co-morbidities. Nu-tritional complications associated with bariatric surgery can be prevented by life-long nutritional monitoring with the administration of multi-vitamins and mineral supplements according to the patient’s needs.
Core tip: Bariatric surgery is increasingly and successfully applied for the treatment of morbid obesity. In spite of multiple clinical benefits, i.e., durable weight loss and improvement/reversal of many comorbidities, a number of nutritional complications can develop especially in the long term, which could cause serious detriment to patients’ health. We examine some important clinical conditions that are caused by the deficit of vitamins and micronutrients, such as anemia, osteoporosis, and malnutrition. We also discuss the importance of careful pre-operative assessments and the correction of pre-existing nutritional deficiencies, and present the current recommendations for an appropriate biochemical and nutritional monitoring in the long term.