Nutritional status prior to bariatric surgery for severe obesity: a review

Obesity pandemic represents a threat to public health of paramount importance. Bariatric surgery represents the most effective and long-lasting treatment for severe obesity so far. The nutritional status of obese patients seeking bariatric surgery is impaired prior to surgery because of prevalent nutritional deficiencies. In addition, excess micronutrient levels may also occur, although this finding is not common. The onset of nutritional anomalies encountered in bariatric surgery candidates might stem from the following: obesity itself, poor quality food choices, preoperative weight loss or insufficient/excessive preoperative oral supplementation with vitamins and minerals. Nutritional management should begin preoperatively and should include a comprehensive assessment in order to identify those patients with clinical or subclinical deficiencies and hypervitaminoses. This paper provides background information on the nutritional status of bariatric surgery candidates, as well as on the prevalence and clinical significance of the most common micronutrient deficiencies and excess levels reported preoperatively among these patients.