Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Bariatric surgery: Postoperative nutritional management

Robert F Kushner, MD
Susan Cummings, MS, RD
Daniel M Herron, MD, FACS, FASMBS
Section Editor
Daniel Jones, MD
Deputy Editor
Wenliang Chen, MD, PhD


The goals of bariatric operations include maximizing weight loss and maintaining or achieving nutritional health while preventing micronutrient deficiencies and lean body mass loss [1,2]. Deficiencies of micronutrients following bariatric surgery can arise from several mechanisms that include preoperative deficiency, reduced dietary intake, malabsorption, and inadequate supplementation. Since obesity is a risk factor of malnutrition and micronutrient deficiencies, all patients should be screened and deficiencies corrected prior to surgery. The postoperative diet and texture progression, micronutrient deficiencies, and their management are reviewed here.

Bypass procedures, such as Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion with duodenal switch (BPD/DS), are known to cause micronutrient malabsorption [2-8]. The sleeve gastrectomy (SG), which is the most commonly performed bariatric procedure in certain regions, does not involve intestinal bypass but can still lead to certain nutritional deficits. Any bariatric procedure can result in malnutrition if a proper diet is not followed. The specific bariatric procedures, indications, and outcomes are reviewed elsewhere and include the following topics:

(See "Bariatric procedures for the management of severe obesity: Descriptions".)

(See "Bariatric operations for management of obesity: Indications and preoperative preparation".)

(See "Bariatric operations: Perioperative morbidity and mortality".)

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Oct 2017. | This topic last updated: Oct 10, 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. American Society for Metabolic and Bariatric Surgery position statement on sleeve gastrectomy as a bariatric procedure 2007. http://pugetsoundsurgicalcenter.com/sleeve_statement.pdf (Accessed on March 24, 2010).
  2. Bosnic G. Nutritional requirements after bariatric surgery. Crit Care Nurs Clin North Am 2014; 26:255.
  3. Tucker ON, Szomstein S, Rosenthal RJ. Nutritional consequences of weight-loss surgery. Med Clin North Am 2007; 91:499.
  4. Gong K, Gagner M, Pomp A, et al. Micronutrient deficiencies after laparoscopic gastric bypass: recommendations. Obes Surg 2008; 18:1062.
  5. Dalcanale L, Oliveira CP, Faintuch J, et al. Long-term nutritional outcome after gastric bypass. Obes Surg 2010; 20:181.
  6. Adami GF, Meneghelli A, Scopinaro N. Night eating and binge eating disorder in obese patients. Int J Eat Disord 1999; 25:335.
  7. Topart P, Becouarn G, Sallé A, Ritz P. Biliopancreatic diversion requires multiple vitamin and micronutrient adjustments within 2 years of surgery. Surg Obes Relat Dis 2014; 10:936.
  8. van Rutte PW, Aarts EO, Smulders JF, Nienhuijs SW. Nutrient deficiencies before and after sleeve gastrectomy. Obes Surg 2014; 24:1639.
  9. Allied Health Sciences Section Ad Hoc Nutrition Committee, Aills L, Blankenship J, et al. ASMBS Allied Health Nutritional Guidelines for the Surgical Weight Loss Patient. Surg Obes Relat Dis 2008; 4:S73.
  10. Mechanick JI, Youdim A, Jones DB, et al. Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery. Obesity (Silver Spring) 2013; 21 Suppl 1:S1.
  11. Moore CE, Sherman V. Vitamin D supplementation efficacy: sleeve gastrectomy versus gastric bypass surgery. Obes Surg 2014; 24:2055.
  12. Ferrer R, Pardina E, Rossell J, et al. Haematological parameters and serum trace elements in "healthy" and "unhealthy" morbidly obese patients before and after gastric bypass. Clin Nutr 2015; 34:276.
  13. https://health.gov/dietaryguidelines/2015/guidelines/appendix-7/ (Accessed on July 26, 2017).
  14. Ortega J, Ortega-Evangelio G, Cassinello N, Sebastia V. What are obese patients able to eat after Roux-en-Y gastric bypass? Obes Facts 2012; 5:339.
  15. Schweiger C, Weiss R, Keidar A. Effect of different bariatric operations on food tolerance and quality of eating. Obes Surg 2010; 20:1393.
  16. Nelson WK, Fatima J, Houghton SG, et al. The malabsorptive very, very long limb Roux-en-Y gastric bypass for super obesity: results in 257 patients. Surgery 2006; 140:517.
  17. Sweeney TE, Morton JM. Metabolic surgery: action via hormonal milieu changes, changes in bile acids or gut microbiota? A summary of the literature. Best Pract Res Clin Gastroenterol 2014; 28:727.
  18. Yousseif A, Emmanuel J, Karra E, et al. Differential effects of laparoscopic sleeve gastrectomy and laparoscopic gastric bypass on appetite, circulating acyl-ghrelin, peptide YY3-36 and active GLP-1 levels in non-diabetic humans. Obes Surg 2014; 24:241.
  19. Tremaroli V, Karlsson F, Werling M, et al. Roux-en-Y Gastric Bypass and Vertical Banded Gastroplasty Induce Long-Term Changes on the Human Gut Microbiome Contributing to Fat Mass Regulation. Cell Metab 2015; 22:228.
  20. American Society for Metabolic and Bariatric Surgery position statement on sleeve gastrectomy as a bariatric procedure 2007; http://pugetsoundsurgicalcenter.com/sleeve_statement.pdf (Accessed on March 24, 2010).
  21. Scopinaro N, Gianetta E, Adami GF, et al. Biliopancreatic diversion for obesity at eighteen years. Surgery 1996; 119:261.
  22. Bojsen-Møller KN, Jacobsen SH, Dirksen C, et al. Accelerated protein digestion and amino acid absorption after Roux-en-Y gastric bypass. Am J Clin Nutr 2015; 102:600.
  23. Gracia JA, Martínez M, Elia M, et al. Obesity surgery results depending on technique performed: long-term outcome. Obes Surg 2009; 19:432.
  24. Soenen S, Martens EA, Hochstenbach-Waelen A, et al. Normal protein intake is required for body weight loss and weight maintenance, and elevated protein intake for additional preservation of resting energy expenditure and fat free mass. J Nutr 2013; 143:591.
  25. Flancbaum L, Belsley S, Drake V, et al. Preoperative nutritional status of patients undergoing Roux-en-Y gastric bypass for morbid obesity. J Gastrointest Surg 2006; 10:1033.
  26. Bloomberg RD, Fleishman A, Nalle JE, et al. Nutritional deficiencies following bariatric surgery: what have we learned? Obes Surg 2005; 15:145.
  27. Ledoux S, Msika S, Moussa F, et al. Comparison of nutritional consequences of conventional therapy of obesity, adjustable gastric banding, and gastric bypass. Obes Surg 2006; 16:1041.
  28. Gehrer S, Kern B, Peters T, et al. Fewer nutrient deficiencies after laparoscopic sleeve gastrectomy (LSG) than after laparoscopic Roux-Y-gastric bypass (LRYGB)-a prospective study. Obes Surg 2010; 20:447.
  29. Parrott J, Frank L, Rabena R, et al. American Society for Metabolic and Bariatric Surgery Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient 2016 Update: Micronutrients. Surg Obes Relat Dis 2017; 13:727.
  30. Davies DJ, Baxter JM, Baxter JN. Nutritional deficiencies after bariatric surgery. Obes Surg 2007; 17:1150.
  31. Clements RH, Katasani VG, Palepu R, et al. Incidence of vitamin deficiency after laparoscopic Roux-en-Y gastric bypass in a university hospital setting. Am Surg 2006; 72:1196.
  32. Schweitzer DH, Posthuma EF. Prevention of vitamin and mineral deficiencies after bariatric surgery: evidence and algorithms. Obes Surg 2008; 18:1485.
  33. Aasheim ET, Björkman S, Søvik TT, et al. Vitamin status after bariatric surgery: a randomized study of gastric bypass and duodenal switch. Am J Clin Nutr 2009; 90:15.
  34. Slater GH, Ren CJ, Siegel N, et al. Serum fat-soluble vitamin deficiency and abnormal calcium metabolism after malabsorptive bariatric surgery. J Gastrointest Surg 2004; 8:48.
  35. Pereira S, Saboya C, Chaves G, Ramalho A. Class III obesity and its relationship with the nutritional status of vitamin A in pre- and postoperative gastric bypass. Obes Surg 2009; 19:738.
  36. Hamoui N, Anthone G, Crookes PF. Calcium metabolism in the morbidly obese. Obes Surg 2004; 14:9.
  37. Sánchez-Hernández J, Ybarra J, Gich I, et al. Effects of bariatric surgery on vitamin D status and secondary hyperparathyroidism: a prospective study. Obes Surg 2005; 15:1389.
  38. Hamoui N, Kim K, Anthone G, Crookes PF. The significance of elevated levels of parathyroid hormone in patients with morbid obesity before and after bariatric surgery. Arch Surg 2003; 138:891.
  39. Peterson LA, Cheskin LJ, Furtado M, et al. Malnutrition in Bariatric Surgery Candidates: Multiple Micronutrient Deficiencies Prior to Surgery. Obes Surg 2016; 26:833.
  40. Pereira SE, Saboya CJ, Saunders C, Ramalho A. Serum levels and liver store of retinol and their association with night blindness in individuals with class III obesity. Obes Surg 2012; 22:602.
  41. Zalesin KC, Miller WM, Franklin B, et al. Vitamin a deficiency after gastric bypass surgery: an underreported postoperative complication. J Obes 2011; 2011.
  42. Institute of Medicine, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Calcium and Vitamin D. National Academy of Sciences; Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, Washington, DC, DC.
  43. Mechanick JI, Youdim A, Jones DB, et al. Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery. Surg Obes Relat Dis 2013; 9:159.
  44. Ledoux S, Calabrese D, Bogard C, et al. Long-term evolution of nutritional deficiencies after gastric bypass: an assessment according to compliance to medical care. Ann Surg 2014; 259:1104.
  45. Iannelli A, Addeo P, Novellas S, Gugenheim J. Wernicke's encephalopathy after laparoscopic Roux-en-Y gastric bypass: a misdiagnosed complication. Obes Surg 2010; 20:1594.
  46. Kaidar-Person O, Person B, Szomstein S, Rosenthal RJ. Nutritional deficiencies in morbidly obese patients: a new form of malnutrition? Part A: vitamins. Obes Surg 2008; 18:870.
  47. Sechi G, Serra A. Wernicke's encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol 2007; 6:442.
  48. Lakhani SV, Shah HN, Alexander K, et al. Small intestinal bacterial overgrowth and thiamine deficiency after Roux-en-Y gastric bypass surgery in obese patients. Nutr Res 2008; 28:293.
  49. Saltzman E, Karl JP. Nutrient deficiencies after gastric bypass surgery. Annu Rev Nutr 2013; 33:183.
  50. Carrodeguas L, Kaidar-Person O, Szomstein S, et al. Preoperative thiamine deficiency in obese population undergoing laparoscopic bariatric surgery. Surg Obes Relat Dis 2005; 1:517.
  51. Aasheim ET. Wernicke encephalopathy after bariatric surgery: a systematic review. Ann Surg 2008; 248:714.
  52. Becker DA, Balcer LJ, Galetta SL. The Neurological Complications of Nutritional Deficiency following Bariatric Surgery. J Obes 2012; 2012:608534.
  53. Rudnicki SA. Prevention and treatment of peripheral neuropathy after bariatric surgery. Curr Treat Options Neurol 2010; 12:29.
  54. Galvin R, Bråthen G, Ivashynka A, et al. EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy. Eur J Neurol 2010; 17:1408.
  55. Bal BS, Finelli FC, Shope TR, Koch TR. Nutritional deficiencies after bariatric surgery. Nat Rev Endocrinol 2012; 8:544.
  56. Thomson AD, Marshall EJ. The treatment of patients at risk of developing Wernicke's encephalopathy in the community. Alcohol Alcohol 2006; 41:159.
  57. Foster D, Falah M, Kadom N, Mandler R. Wernicke encephalopathy after bariatric surgery: losing more than just weight. Neurology 2005; 65:1987; discussion 1847.
  58. Shah HN, Bal BS, Finelli FC, Koch TR. Constipation in patients with thiamine deficiency after Roux-en-Y gastric bypass surgery. Digestion 2013; 88:119.
  59. Skroubis G, Sakellaropoulos G, Pouggouras K, et al. Comparison of nutritional deficiencies after Roux-en-Y gastric bypass and after biliopancreatic diversion with Roux-en-Y gastric bypass. Obes Surg 2002; 12:551.
  60. Brolin RE, LaMarca LB, Kenler HA, Cody RP. Malabsorptive gastric bypass in patients with superobesity. J Gastrointest Surg 2002; 6:195.
  61. Brolin RE, Leung M. Survey of vitamin and mineral supplementation after gastric bypass and biliopancreatic diversion for morbid obesity. Obes Surg 1999; 9:150.
  62. Juhasz-Pocsine K, Rudnicki SA, Archer RL, Harik SI. Neurologic complications of gastric bypass surgery for morbid obesity. Neurology 2007; 68:1843.
  63. Smith CD, Herkes SB, Behrns KE, et al. Gastric acid secretion and vitamin B12 absorption after vertical Roux-en-Y gastric bypass for morbid obesity. Ann Surg 1993; 218:91.
  64. Marcuard SP, Sinar DR, Swanson MS, et al. Absence of luminal intrinsic factor after gastric bypass surgery for morbid obesity. Dig Dis Sci 1989; 34:1238.
  65. Alexandrou A, Armeni E, Kouskouni E, et al. Cross-sectional long-term micronutrient deficiencies after sleeve gastrectomy versus Roux-en-Y gastric bypass: a pilot study. Surg Obes Relat Dis 2014; 10:262.
  66. Hakeam HA, O'Regan PJ, Salem AM, et al. Impact of laparoscopic sleeve gastrectomy on iron indices: 1 year follow-up. Obes Surg 2009; 19:1491.
  67. Kehagias I, Karamanakos SN, Argentou M, Kalfarentzos F. Randomized clinical trial of laparoscopic Roux-en-Y gastric bypass versus laparoscopic sleeve gastrectomy for the management of patients with BMI < 50 kg/m2. Obes Surg 2011; 21:1650.
  68. Pech N, Meyer F, Lippert H, et al. Complications and nutrient deficiencies two years after sleeve gastrectomy. BMC Surg 2012; 12:13.
  69. Eltweri AM, Bowrey DJ, Sutton CD, et al. An audit to determine if vitamin b12 supplementation is necessary after sleeve gastrectomy. Springerplus 2013; 2:218.
  70. Ben-Porat T, Elazary R, Yuval JB, et al. Nutritional deficiencies after sleeve gastrectomy: can they be predicted preoperatively? Surg Obes Relat Dis 2015; 11:1029.
  71. Caudill MA. Folate bioavailability: implications for establishing dietary recommendations and optimizing status. Am J Clin Nutr 2010; 91:1455S.
  72. Ernst B, Thurnheer M, Schmid SM, Schultes B. Evidence for the necessity to systematically assess micronutrient status prior to bariatric surgery. Obes Surg 2009; 19:66.
  73. Brolin RE, Gorman RC, Milgrim LM, Kenler HA. Multivitamin prophylaxis in prevention of post-gastric bypass vitamin and mineral deficiencies. Int J Obes 1991; 15:661.
  74. National Institute of Health OoDS.2015.Folate Dietary Supplement Fact Sheet; https://ods.od.nih.gov/factsheets/list-all/Folate/ (Accessed on July 27, 2017).
  75. Force USPST.2015.Folic Acid for the Preventin of Neural Tube Defects: Preventive 2000 Medication Final Update Summary: Folic Acid to Prevent Neural Tube Defects: Preventive Medication; https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/folic-acid-to-prevent-neural-tube-defects-preventive-medication (Accessed on July 27, 2017).
  76. Saltzman E, Anderson W, Apovian CM, et al. Criteria for patient selection and multidisciplinary evaluation and treatment of the weight loss surgery patient. Obes Res 2005; 13:234.
  77. O'Leary F, Samman S. Vitamin B12 in health and disease. Nutrients 2010; 2:299.
  78. Rhode BM, Shustik C, Christou NV, MacLean LD. Iron absorption and therapy after gastric bypass. Obes Surg 1999; 9:17.
  79. Obinwanne KM, Fredrickson KA, Mathiason MA, et al. Incidence, treatment, and outcomes of iron deficiency after laparoscopic Roux-en-Y gastric bypass: a 10-year analysis. J Am Coll Surg 2014; 218:246.
  80. Salgado W Jr, Modotti C, Nonino CB, Ceneviva R. Anemia and iron deficiency before and after bariatric surgery. Surg Obes Relat Dis 2014; 10:49.
  81. Vargas-Ruiz AG, Hernández-Rivera G, Herrera MF. Prevalence of iron, folate, and vitamin B12 deficiency anemia after laparoscopic Roux-en-Y gastric bypass. Obes Surg 2008; 18:288.
  82. Madan AK, Orth WS, Tichansky DS, Ternovits CA. Vitamin and trace mineral levels after laparoscopic gastric bypass. Obes Surg 2006; 16:603.
  83. Heber D, Greenway FL, Kaplan LM, et al. Endocrine and nutritional management of the post-bariatric surgery patient: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2010; 95:4823.
  84. Sallé A, Demarsy D, Poirier AL, et al. Zinc deficiency: a frequent and underestimated complication after bariatric surgery. Obes Surg 2010; 20:1660.
  85. Di Martino G, Matera MG, De Martino B, et al. Relationship between zinc and obesity. J Med 1993; 24:177.
  86. Balsa JA, Botella-Carretero JI, Gómez-Martín JM, et al. Copper and zinc serum levels after derivative bariatric surgery: differences between Roux-en-Y Gastric bypass and biliopancreatic diversion. Obes Surg 2011; 21:744.
  87. Kaidar-Person O, Person B, Szomstein S, Rosenthal RJ. Nutritional deficiencies in morbidly obese patients: a new form of malnutrition? Part B: minerals. Obes Surg 2008; 18:1028.
  88. Dolan K, Hatzifotis M, Newbury L, et al. A clinical and nutritional comparison of biliopancreatic diversion with and without duodenal switch. Ann Surg 2004; 240:51.
  89. Beers MH. The Merck Manual of Diagnosis and Therapy., Merck Research Laboratories; 2006, White Station, NJ 2006.
  90. Mason KE. A conspectus of research on copper metabolism and requirements of man. J Nutr 1979; 109:1979.
  91. Wapnir RA. Copper absorption and bioavailability. Am J Clin Nutr 1998; 67:1054S.
  92. Shankar P, Boylan M, Sriram K. Micronutrient deficiencies after bariatric surgery. Nutrition 2010; 26:1031.
  93. Griffith DP, Liff DA, Ziegler TR, et al. Acquired copper deficiency: a potentially serious and preventable complication following gastric bypass surgery. Obesity (Silver Spring) 2009; 17:827.
  94. Gletsu-Miller N, Broderius M, Frediani JK, et al. Incidence and prevalence of copper deficiency following roux-en-y gastric bypass surgery. Int J Obes (Lond) 2012; 36:328.
  95. Chhetri SK, Mills RJ, Shaunak S, Emsley HC. Copper deficiency. BMJ 2014; 348:g3691.
  96. Lapointe-Gagner XA, Gagner M. Micronutrients deficiencies after laparoscopic gastric bypass and duodenal switch. A comparative study. Surg Obes Rel Dis 2005; 1:285.
  97. Institute of Medicine (U.S.). Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids, National Academy Press, Washington DC 2000.
  98. Al-Matary A, Hussain M, Ali J. Selenium: a brief review and a case report of selenium responsive cardiomyopathy. BMC Pediatr 2013; 13:39.
  99. Shah M, Sharma A, Wermers RA, et al. Hypocalcemia After Bariatric Surgery: Prevalence and Associated Risk Factors. Obes Surg 2017; 27:2905.
  100. Johnson JM, Maher JW, DeMaria EJ, et al. The long-term effects of gastric bypass on vitamin D metabolism. Ann Surg 2006; 243:701.
  101. Chan LN, Neilson CH, Kirk EA, et al. Optimization of Vitamin D Status After Roux-en-Y Gastric Bypass Surgery in Obese Patients Living in Northern Climate. Obes Surg 2015; 25:2321.
  102. Coates PS, Fernstrom JD, Fernstrom MH, et al. Gastric bypass surgery for morbid obesity leads to an increase in bone turnover and a decrease in bone mass. J Clin Endocrinol Metab 2004; 89:1061.
  103. Ybarra J, Sánchez-Hernández J, Gich I, et al. Unchanged hypovitaminosis D and secondary hyperparathyroidism in morbid obesity after bariatric surgery. Obes Surg 2005; 15:330.
  104. Youssef Y, Richards WO, Sekhar N, et al. Risk of secondary hyperparathyroidism after laparoscopic gastric bypass surgery in obese women. Surg Endosc 2007; 21:1393.
  105. Pepino MY, Stein RI, Eagon JC, Klein S. Bariatric surgery-induced weight loss causes remission of food addiction in extreme obesity. Obesity (Silver Spring) 2014; 22:1792.
  106. Mills MJ, Stunkard AJ. Behavioral changes following surgery for obesity. Am J Psychiatry 1976; 133:527.
  107. Crisp AH, Kalucy RS, Pilkington TR, Gazet JC. Some psychosocial consequences of ileojejunal bypass surgery. Am J Clin Nutr 1977; 30:109.