Nutritional guidance, monitoring, and supplementation before and after bariatric surgery - Are we doing this correctly?

Background and aims: minimizing nutritional depletions after a Roux-en-Y gastric bypass (RYGB) may improve clinical results in the treatment of obesity. We evaluated nutritional aspects of obese women undergoing RYGB at a reference university hospital with a department specialized in bariatric surgery. Method: based on the Dietary Reference Intakes developed by the Food and Nutrition Council, Institute of Medicine, and the guidelines issued by the American Society for Metabolic and Bariatric Surgery, we assessed the quantitative and qualitative adequacy of nutritional intake, supplementation, and biochemical monitoring of 20 women both before and 3 and 12 months after a RYGB. Data on nutritional intake was obtained by applying different food surveys, quantitatively interpreted by the Virtual Nutri Plus® software and using reference nutritional databases. Results: nutritional intake deficits were already found before the RYGB (p ≤ 0.05). These worsened postoperatively (p ≤ 0.05), a period also marked by a qualitatively poor diet. The nutritional supplementation prescribed did not fully achieve the reference recommendations, and was poorly complied with by patients. Furthermore, nutritional monitoring was not carried out in all patients, recommended biochemical markers were not screened, and vitamin D depletions occurred. Conclusion: our data suggest that institutions specialized in bariatric patient care may not be adequately adhering to well known guidelines, or applying efficient strategies to improve compliance.