Extensive weight loss prior to bariatric surgery is associated with worse outcomes

Extensive weight loss prior to bariatric surgery is associated with worse outcomes | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Extensive weight loss prior to bariatric surgery is associated with worse outcomes John Pickering, Marcoandrea Giorgi, Emily Ortega-Goddard, Andrew Luhrs This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6815565/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Obesity Surgery → Version 1 posted 8 You are reading this latest preprint version Abstract Background : Weight loss has been shown to favorably affect obesity-related comorbid disease. Prior studies have shown that a 10% preoperative weight loss is associated with fewer complications after gastric bypass surgery. Although the optimal preoperative preparation for bariatric surgery is not standardized, prerequisite weight loss prior to bariatric surgical procedures is often mandated, typically around 10%, and includes a calorie-restrictive preoperative diet. Objectives : To evaluate the association between extensive preoperative weight loss and perioperative outcomes in patients undergoing bariatric surgery. Methods : To determine optimal weight loss prior to bariatric surgery, we compared patients who lost over 10% of their highest weight preoperatively to patients who did not within the MBSAQIP database from 2015-2021, which included over 1.3 million patients. Results : Patients who lost more than 10% of their highest preoperative weight were more likely to experience postoperative complications, including reoperation (1.40% vs 1.21%, p<.001), bleeding (0.85% vs 0.67%, p<.001), emergency department visits (7.11% vs 6.57%, p<.001), and dehydration (3.92% vs 3.61%, p<.001). These differences remained significant with multivariable regression analysis controlling for multiple patient factors and procedure type. Patients who lost more than 10% of their highest preoperative weight were also found to have a lower mortality (0.10% vs 0.08%, p=.04) and readmission (3.92% vs 3.60%, p<.001), however on multivariable regression analysis these findings were not found to be statistically significant. Conclusion : While preoperative weight loss prior to bariatric surgery may be beneficial, , over 10% preoperative weight loss is associated with worse outcomes and should be avoided. Key Points • Over 10% preoperative weight loss is associated with an increased risk of complications after bariatric surgery • Complications include higher rates of reoperation, bleeding, emergency department visits, and dehydration • Limited weight loss (5–10%) preoperatively may be beneficial to improve the ease of surgery by reducing liver size and visceral fat volume • Multidisciplinary support optimizes outcomes and mitigates malnutrition risks Introduction Over the past few decades, the escalating prevalence of obesity has emerged as a significant health challenge. Obesity has been shown to reduce life expectancy by 5 to 20 years. 1 Obesity is closely associated with various comorbidities, including type 2 diabetes mellitus, cardiovascular disease, joint disease, various types of cancer, and an elevated risk of mortality over time. 2 Furthermore, obesity negatively impacts self-reported quality of life and overall well-being. Nonsurgical treatments for severe obesity often yield unsatisfactory outcomes, particularly in the long term. Conversely, bariatric surgery has been shown to not only lead to durable weight loss but to decrease the risk of cardiovascular disease, type 2 diabetes mellitus, and cancer. Bariatric surgery also decreases mortality, with a prospective trial illustrating a reduced overall mortality of 29% over a mean follow-up of 10.9 years. 3 Short-term preoperative weight loss (2–12 weeks) before bariatric surgery serves multiple purposes, including evaluating patient compliance and aiding in patient selection. 4 The primary objective of preoperative weight loss is to enhance the technical ease of the surgery by reducing liver volume and visceral fat volume, which is thought to improve operative exposure and decrease surgical complexity. 4 Prerequisite weight loss before bariatric surgery is often mandated by insurance companies. The effects of short-term preoperative weight loss (2–12 weeks) on surgical outcomes remain inconclusive. Several studies have reported benefits, including decreased 30-day complication rates, 5 shorter operative times, 6 and shorter length of stay. 7 Benotti et al showed that 10% preoperative weight loss was associated with fewer complications after gastric bypass surgery. 8 Conversely, other studies have found negative outcomes after preoperative weight loss. One study found preoperative weight loss to be associated with an increased risk for malnutrition and infection. 9 In an observational study, pre-operative weight loss was not associated with improved postoperative weight loss, comorbidity resolution at 1 year, or lower 30- or 90-day re-admission rates. 10 In a retrospective review of 1,432 bariatric surgery patients, insurance-mandated pre-operative weight-loss programs were not associated with better outcomes at 2 years. 11 In fact, Keith et al found that insurance-mandated pre-operative diets delay treatment and adversely affect weight outcomes. 12 Because of this conflicting data, there has been long-standing uncertainty and debate regarding the value of preoperative weight loss as a requirement for primary bariatric surgery. Exact preoperative weight loss requirements vary among patients, physicians, hospitals, and health insurance payers. Based on the available evidence, the American Society for Metabolic and Bariatric Surgery (ASMBS) issued a position in 2016 stating that there is no definitive evidence that preoperative weight loss significantly impacts postoperative outcomes. 13 Current clinical guidelines by the ASMBS do not recommend preoperative weight loss. 13 There is a critical need to clarify the potential influence of preoperative weight loss on postoperative outcomes. 14 This retrospective review aims to investigate the complication rate of patients with greater than 10% preoperative weight loss before primary bariatric surgery compared to those with less than 10% preoperative weight loss. Methods The present study conducted a retrospective review utilizing publicly available Participant Use Data File (PUF) from 1,318,808 patients who had undergone primary bariatric surgery (Sleeve Gastrectomy or Roux en Y Gastric Bypass) between the years 2015 and 2021 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). This program, encompassing more than 90% of all bariatric surgery programs in the United States and Canada, served as the primary data source for this investigation. The data utilized is publicly available and anonymous MBSAQIP data, which does not require Institutional Review Board (IRB) approval. The study examined the impact of preoperative weight loss on postoperative outcomes following bariatric surgery. Clinical and demographic data were collected at all participating institutions adhering to a standardized protocol. Data analysis was conducted from August 2023 to March 2024. The inclusion criteria included patients > 18 years old who underwent Roux en Y gastric bypass or sleeve gastrectomy as primary bariatric surgery. Exclusion criteria included patients who underwent biliopancreatic diversion with duodenal switch, single anastomosis duodenoileostomy (SADI), revisional procedures, and patients lacking documented preoperative weight loss or postoperative complications. Preoperative weight loss was defined as the patient’s weight immediately before surgery relative to their highest documented weight. Baseline weight is defined as the highest weight documented preoperatively. Preoperative weight loss (%preopWL) was defined as baseline weight minus weight on the day of the bariatric procedure divided by the baseline weight. The data abstracted from each patient included the procedure type, age, baseline patient demographics, highest weight, weight immediately before surgery, co-morbid conditions including smoking, diabetes mellitus (DM), hypertension (HTN), obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD) and 30 day postoperative outcomes (mortality, reoperation, readmission, sepsis, bleed, etc). A multivariable regression analysis was performed for the patients’ preoperative weight loss, controlling for procedure type, DM, ASA > = 3, HTN, HLD, COPD, OSA, GERD, smoking, Dialysis, PCI, and MI. Statistical analysis was performed using STATA software version 14.2 (StataCorp LLC, College Station, TX). Quantitative variables were reported as means with 95% confidence intervals (CI), and descriptive categorical variables were reported as frequencies and proportions. Univariate analysis using t- test or Chi-Square test was used to compare demographic, operative characteristics, and postoperative outcomes between groups. Statistical significance was set at p 10% weight loss group included 97,861 patients, and the 10% weight loss group and 44 years old in the 10% weight loss group and 122.0 kg in the 10% weight loss group and 123.8 kg in the 10% weight loss group were smokers and 7.94% of the patients in the 10% weight loss group, 67.34% underwent a sleeve gastrectomy and 32.66% underwent a Roux en Y gastric bypass. Of the patients in the < 10% weight loss group, 72.75% underwent a sleeve gastrectomy and 27.25% underwent a Roux en Y gastric bypass (Table 2 ). Table 1 Baseline Characteristics of Patients Included in Review Patient factors > 10% weight loss < 10% weight loss p-value Average Age 46 44 < 0.001 Highest Weight (kg) 125.1 122.0 < 0.001 Weight Prior to Surgery (kg) 99.3 123.8 < 0.001 Smoking 6.15% 7.94% < 0.001 HTN 50.86% 42.45% < 0.001 OSA 48.10% 36.55% < 0.001 GERD 34.18% 30.66% < 0.001 DM 28.62% 24.50% < 0.001 HLD 27.27% 22.76% < 0.001 COPD 2.02% 1.42% = 3 79.81% 78.46% < 0.001 PCI 1.94% 1.72% < 0.001 Pulm Emb 0.12% 0.11% 0.495 MI 1.30% 1.17% < 0.001 HTN = hypertension; OSA = obstructive sleep apnea; GERD = gastroesophageal reflux disease; DM = diabetes mellitus; HLD = hyperlipidemia; COPD = chronic obstructive pulmonary disease; ASA = American Society of Anesthesiology class; PCI = percutaneous coronary intervention; Pulm Emb = pulmonary embolism; MI = myocardial infarction Table 2 Procedure Performed Procedure Performed > 10% weight loss < 10% weight loss p-value Sleeve Gastrectomy 65,896 (67.34%) 888,193 (72.75%) < 0.001 Roux en Y Gastric Bypass 31,965 (32.66%) 332,754 (27.25%) < 0.001 Patients who lost more than 10% of their highest preoperative weight were more likely to experience postoperative complications, including reoperation (1.40% vs 1.21%, p < .001), bleeding (0.85% vs 0.67%, p < .001), emergency department visits (7.11% vs 6.57%, p < .001), and dehydration (3.92% vs 3.61%, p < .001) (Table 3 ). These differences remained significant with multivariable regression analysis controlling for multiple patient factors and procedure type (Table 4 ). Patients who lost more than 10% of their highest preoperative weight were also found to have a lower mortality (0.10% vs 0.08%, p = .04) and readmission (3.92% vs 3.60%, p < .001) (Table 3 ). However, after multivariable regression analysis, the mortality rate (OR 0.931, p = .505) and readmission rate (OR 1.022, p = .208) were no longer statistically significant (Table 4 ) Table 3 30 day Postoperative Complications after Bariatric Surgery Complications > 10% weight loss < 10% weight loss p-value Mortality 93 (0.10%) 993 (0.08%) 0.04 Reoperation 1373 (1.40%) 14797 (1.21%) < 0.001 Readmission 3832 (3.92%) 43971 (3.60%) < 0.001 Sepsis 11 (0.01%) 254 (0.01%) 0.54 Bleed 828 (0.85%) 8212 (0.67%) < 0.001 SSI 84 (0.09%) 1056 (0.09%) 0.947 ED Visit 6961 (7.11%) 80239 (6.57%) < 0.001 Dehydration 3833 (3.92%) 44053 (3.61%) 10% preoperative weight loss controlling for procedure type, DM, ASA > = 3, HTN, HLD, COPD, OSA, GERD, Smoking, Dialysis, PCI, MI Complications Odds Ratio 95% CI Low 95% CI High p-value Mortality .9316131 .7563367 1.147509 0.505 Reoperation 1.069116 1.010896 1.13069 0.019 Readmission 1.02205 .9879661 1.057309 0.208 Sepsis .7545072 0. 4091815 1.391268 0.367 Bleed 1.151953 1.071834 1.238061 0.001 SSI .8847012 .7076029 1.106124 0.282 ED Visit 1.065167 1.038309 1.09272 0.001 Dehydration 1.080783 1.044856 1.117945 0.001 Anastomotic Leak 1.008741 .6692509 1.520445 0.967 SSI = surgical site infection ; ED = Emergency Department Discussion Preoperative weight loss before bariatric surgery is often viewed as a strategy to improve the ease of surgery and perioperative risk by decreasing liver size and visceral fat volume. 4 Prior analyses have suggested that patients with obesity can lose 10% of their excess body weight in the weeks prior to surgery without significant perioperative risk. 15 However, other studies have shown increased malnutrition and infection rates with excess preoperative weight loss. 9 Several studies have shown that preoperative weight loss is associated with improved surgical outcomes, 5 , 6 , 7 while others report no reduction in complication rates. 16 Different authors have shown that preoperative weight loss is associated with greater post-surgical total weight loss, 4 while others have shown instead no real benefit. 17 Therefore, further evaluation of the evidence on whether preoperative weight loss leads to improved outcomes is imperative. Dietary restriction prior to surgery is hypothesized to reduce inflammation, improve lipid metabolism, and insulin sensitivity, which supports the importance of continuing investigation towards a well-balanced preoperative treatment program. 18 Different preoperative weight loss approaches may play a critical role in influencing surgical outcomes. Common strategies for preoperative weight loss include protein liquid diets, low-calorie diets (800–1200 kcals/d), very low-calorie diets (VLCDs) (400–800 kcals/d), very-low-calorie ketogenic diet, increased physical activity, and the use of pharmacologic agents such as GLP-1 receptor agonists. These diets typically occur 2–12 weeks prior to surgery and each method varies in its risk profile, effectiveness, and patient adherence. For example, protein liquid diets are simple for patients and are generally well-tolerated, but lack variety which could lead to poor adherence. VLCDs lead to rapid weight loss but increase the risk of malnutrition if not closely monitored. 19 One study by Contreras et al compared an 800 kcal/day VLCD consisting solely of shakes with a 1200 kcal/day diet that incorporated shakes and solid foods. 20 The VLCD group achieved greater weight loss while reporting similar adherence levels. 20 However, patients in the VLCD group experienced more side effects, including dizziness, fatigue, and weakness. 20 The introduction of GLP-1 receptor agonists, such as semaglutide, represents a significant advancement in medical weight loss. These medications have demonstrated efficacy in achieving substantial weight loss while also reducing risks associated with cardiovascular disease and diabetes. 21 Their role in preoperative preparation is increasingly being recognized, as they may help patients achieve moderate, controlled weight loss without the nutritional deficiencies that can accompany calorie-restrictive diets. 22 However, GLP-1 receptor agonists should be used with caution in the immediate perioperative phase due to the risk of delayed gastric emptying, which can lead to residual gastric contents on the day of the procedure despite traditional fasting. 23 There have been incidents of pulmonary aspiration of gastric contents during sedation or anesthesia in patients taking GLP-1 receptor agonists in the perioperative period. 23 Future studies should explore how the integration of GLP-1 receptor agonists into preoperative bariatric surgery protocols could effect preoperative weight loss as well as surgical outcomes. Some surgeons may adopt a more stringent approach in counseling patients about preoperative weight loss expectations. This can impact patients’ nutritional status, either exacerbating malnutrition or influencing their adherence to prescribed weight loss plans. A more aggressive approach may have unintended consequences, such as increasing stress and potentially reducing the likelihood of meeting weight loss goals. Conversely, a more supportive and individualized counseling strategy could help improve patient adherence and nutritional outcomes prior to surgery. Patients who struggle to adhere to a strict preoperative diet should not be excluded from undergoing bariatric surgery, as these diets are designed to improve the technical ease of surgery rather than serve as absolute barriers. It is also important to distinguish preoperative dietary recommendations from insurance-mandated preoperative diet requirements, as they serve different purposes and should not be conflated. To ensure patients remain within the optimal preoperative weight loss range, bariatric surgery programs should consider implementing several strategies. Standardized preoperative nutritional assessment and counseling is critical as most patients seeking bariatric surgerу have at least one micronutrient deficiency. 24 A multidisciplinary approach should involving dietitians, behavioral therapists, and surgeons, who can help patients set realistic weight loss goals and adhere to evidence-based dietary plans. Regular monitoring and adjustments (such as weekly or bi-weekly weight measurements and follow-up consultations) can identify deviations early and facilitate early intervention. For patients struggling with dietary compliance or requiring rapid weight loss, pharmacologic agents such as GLP-1 receptor agonists (e.g., semaglutide) should be considered. Finally, revising insurance policies to adopt less rigid weight loss requirements could reduce the pressure for excessive preoperative weight loss, aligning practices with current evidence and ensuring better patient outcomes. Assessing the effect of preoperative weight loss on perioperative complication rates is difficult, given the overall low incidence of bariatric surgery complications and, consequently, the large study population needed to reach statistical significance. The current mortality and major complication rates of bariatric surgery of less than 0.3% and less than 3%, respectively. 9 The major strength of this review lies in the large study population. In this study, patients with greater than 10% preoperative weight loss experienced an increased incidence of several postoperative complications, potentially due to altered physiology resulting from significant weight reduction. The reoperation rate (1.40% vs. 1.21%) may be due to impaired tissue healing as a result of malnutrition from rapid weight loss. 2 Similarly, the higher readmission rate (3.92% vs. 3.60%) may be attributed to an increased risk of postoperative infections or nutritional deficiencies, which are commonly observed in patients experiencing rapid weight loss. The bleeding rate (0.85% vs. 0.67%) is also higher, which may result from a variety of factors, including altered coagulation profiles, nutritional deficiencies, and possibly more fragile tissue after significant weight loss, though additional variables such as surgical technique or comorbidities could also contribute. Increased emergency department visits (7.11% vs. 6.57%) could stem from dehydration, electrolyte imbalances, sarcopenia, or gastrointestinal issues, which are more common in this group. Dehydration (3.92% vs. 3.61%) is more prevalent due to electrolyte and fluid imbalances following significant weight loss. However, many complications, such as sepsis, surgical site infections, and anastomotic leaks, were not statistically significant between the groups, highlighting that the overall impact of preoperative weight loss may not be as pronounced for some adverse outcomes. The implications of our study may be applicable for other abdominal surgeries as well. In cases that involve a bowel anastomosis, it is well documented that malnutrition is associated with worse outcomes. 25 However, excess visceral fat has also been associated with longer operative time and longer lengths of stay, as well as increased wound infections and increased overall complication rates. 26 This database review demonstrates that greater than 10% of preoperative weight loss is associated with a variety of surgical complications postoperatively. Given the retrospective nature of the review, the findings in this study will require further evaluation, such as a randomized, prospective trial. Limitations The limitations of this study are in large part due to the retrospective design. One inherent limitation of the PUF data was the inability to account for the different time intervals over which the preoperative weight loss occurred between patients. The specific methods used for preoperative weight loss are also unknown and presumably vary widely across centers; these include fixed diets, use of weight loss medications, exercise regimens, and more, all of which are likely influential in the outcomes data measured. The demographic differences between the two groups in this study may have contributed to the observed outcomes. Patients in the > 10% preoperative weight loss group were older and presented with higher rates of some of the obesity-related comorbidities such as hypertension, obstructive sleep apnea, and diabetes mellitus. These factors likely indicate a population with more advanced disease and potentially less physiological reserve, which could predispose them to worse postoperative outcomes. Additionally, these comorbidities may influence surgeons' decisions to pursue more aggressive weight loss strategies preoperatively, potentially introducing selection bias. The patients in the > 10% weight loss group were also more likely to have a Roux en Y gastric bypass compared to the < 10% weight loss group (32.66% vs 27.25%), which could have contributed to the findings. However, regression analysis was performed and validated these findings (with the exception of the mortality rate and readmission rate) supporting the robustness of our results despite potential confounding factors. Conclusion While limited weight loss (5–10%) prior to bariatric surgery may be beneficial, over 10% preoperative weight loss is associated with worse outcomes in the early postoperative period, including dehydration, bleeding, ED visits, and reoperation. Therefore, excessive preoperative weight loss should be avoided. To optimize preoperative weight loss, we recommend multidisciplinary preoperative support including a nutritional treatment program as well as additional weight measurement on the day of surgery. Abbreviations %preopWL : Percentage preoperative weight loss ASA : American Society of Anesthesiologists ASMBS : American Society for Metabolic and Bariatric Surgery CI : Confidence Interval COPD : Chronic Obstructive Pulmonary Disease DM : Diabetes Mellitus ED : Emergency Department GERD : Gastroesophageal Reflux Disease HLD : Hyperlipidemia HTN : Hypertension MBSAQIP : Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program MI : Myocardial Infarction PCI : Percutaneous Coronary Intervention PUF : Participant Use Data File Pulm Emb : Pulmonary Embolism SSI : Surgical Site Infection VLCDs : Very Low-Calorie Diets Declarations Conflicts of Interest The authors declare that they have no conflicts of interest relevant to this manuscript. Declaration of generative AI and AI-assisted technologies in the writing process During the preparation of this work the author used AI in order to improve language and readability, with caution. After using this tool, the author reviewed and edited the content as needed and take full responsibility for the content of the publication. Author Contribution J.P. drafted the main manuscript text. A.L. was responsible for data preparation and contributed to data analysis and interpretation. M.G., E.O., and A.L. provided substantial contributions in reviewing the manuscript and provided critical revisions to the text. All authors approved the final version for submission. References Prospective Studies Collaboration; Whitlock G, Lewington S, Sherliker P, Clarke R, Emberson J, Halsey J, et al. Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. Lancet. 2009;373(9669):1083–96. doi: 10.1016/S0140-6736(09)60318-4 . Epub 2009 Mar 18. PMID: 19299006; PMCID: PMC2662372. Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292(14):1724-37. doi: 10.1001/jama.292.14.1724 . Erratum in: JAMA. 2005;293(14):1728. PMID: 15479938. Carlsson LMS, Sjöholm K, Jacobson P, Andersson-Assarsson JC, Svensson PA, Taube M, et al. Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study. N Engl J Med. 2020;383(16):1535–1543. doi: 10.1056/NEJMoa2002449 . PMID: 33053284; PMCID: PMC7580786. Romaen IFL, Jense MTF, Palm-Meinders IH, de Witte E, Fransen SAF, Greve JWM, et al. Higher Preoperative Weight loss Is Associated with Greater Weight Loss up to 12 Months After Bariatric Surgery. Obes Surg. 2022;32(9):2860–2868. doi: 10.1007/s11695-022-06176-9 . Epub 2022 Jul 5. PMID: 35788954. Van Nieuwenhove Y, Dambrauskas Z, Campillo-Soto A, van Dielen F, Wiezer R, Janssen I, Kramer M, Thorell A. Preoperative very low-calorie diet and operative outcome after laparoscopic gastric bypass: a randomized multicenter study. Arch Surg. 2011;146(11):1300-5. doi: 10.1001/archsurg.2011.273 . PMID: 22106323. Ekici U, Ferhatoglu MF. Perioperative and Postoperative Effects of Preoperative Low-Calorie Restrictive Diets on Patients Undergoing Laparoscopic Sleeve Gastrectomy. J Gastrointest Surg. 2020;24(2):313–319. doi: 10.1007/s11605-019-04157-5 . Epub 2019 Feb 20. PMID: 30788716. Roman M, Monaghan A, Serraino GF, Miller D, Pathak S, Lai F, Zaccardi F, Ghanchi A, Khunti K, Davies MJ, Murphy GJ. Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes. Br J Surg. 2019;106(3):181–189. doi: 10.1002/bjs.11001. Epub 2018 Oct 17. PMID: 30328098. Benotti PN, Still CD, Wood GC, Akmal Y, King H, El Arousy H, et al. Preoperative weight loss before bariatric surgery. Arch Surg. 2009;144(12):1150–5. doi: 10.1001/archsurg.2009.209 . PMID: 20026834; PMCID: PMC4139063. Tewksbury C, Crowley N, Parrott JM, Andromalos L, Isom KA, Smith E, et al. Weight Loss Prior to Bariatric Surgery and 30-Day Mortality, Readmission, Reoperation, and Intervention: an MBSAQIP Analysis of 349,016 Cases. Obes Surg. 2019;29(11):3622–3628. doi: 10.1007/s11695-019-04041-w . PMID: 31240533. Conaty EA, Bonamici NJ, Gitelis ME, Johnson BJ, DeAsis F, Carbray JM, Lapin B, Joehl R, Denham W, Linn JG, Haggerty SP, Ujiki MB. Efficacy of a Required Preoperative Weight Loss Program for Patients Undergoing Bariatric Surgery. J Gastrointest Surg. 2016;20(4):667–73. doi: 10.1007/s11605-016-3093-3. Epub 2016 Feb 10. PMID: 26864165. Horwitz D, Saunders JK, Ude-Welcome A, Parikh M. Insurance-mandated medical weight management before bariatric surgery. Surg Obes Relat Dis. 2016 Mar-Apr;12(3):496–499. doi: 10.1016/j.soard.2015.09.004. Epub 2015 Sep 21. PMID: 26775043. Keith CJ Jr, Goss LE, Blackledge CD, Stahl RD, Grams J. Insurance-mandated preoperative diet and outcomes after bariatric surgery. Surg Obes Relat Dis. 2018;14(5):631–636. doi: 10.1016/j.soard.2018.01.017 . Epub 2018 Feb 2. PMID: 29454535. Kim JJ, Rogers AM, Ballem N, Schirmer B; American Society for Metabolic and Bariatric Surgery Clinical Issues Committee. ASMBS updated position statement on insurance mandated preoperative weight loss requirements. Surg Obes Relat Dis. 2016;12(5):955–959. Sun Y, Liu B, Smith JK, Correia MLG, Jones DL, Zhu Z, et al. Association of Preoperative Body Weight and Weight Loss With Risk of Death After Bariatric Surgery. JAMA Netw Open. 2020;3(5):e204803. doi: 10.1001/jamanetworkopen.2020.4803 . PMID: 32407504; PMCID: PMC7225906. Tarnoff M, Kaplan LM, Shikora S. An evidenced-based assessment of preoperative weight loss in bariatric surgery. Obes Surg. 2008;18(9):1059–61. doi: 10.1007/s11695-008-9603-y . Epub 2008 Jun 28. PMID: 18587621. Holderbaum M, Casagrande DS, Sussenbach S, Buss C. Effects of very low calorie diets on liver size and weight loss in the preoperative period of bariatric surgery: a systematic review. Surg Obes Relat Dis. 2018;14(2):237–244. doi: 10.1016/j.soard.2017.09.531. Epub 2017 Oct 2. PMID: 29239795. Still CD, Benotti P, Wood GC, Gerhard GS, Petrick A, Reed M, et al. Outcomes of preoperative weight loss in high-risk patients undergoing gastric bypass surgery. Arch Surg. 2007;142(10):994-8; discussion 999. doi: 10.1001/archsurg.142.10.994 . PMID: 17938314. Bettini S, Belligoli A, Fabris R, Busetto L. Diet approach before and after bariatric surgery. Rev Endocr Metab Disord. 2020;21(3):297–306. doi: 10.1007/s11154-020-09571-8 . Erratum in: Rev Endocr Metab Disord. 2020;: PMID: 32734395; PMCID: PMC7455579. Janssen TAH, Van Every DW, Phillips SM. The impact and utility of very low-calorie diets: the role of exercise and protein in preserving skeletal muscle mass. Curr Opin Clin Nutr Metab Care. 2023;26(6):521–527. doi: 10.1097/MCO.0000000000000980 . Epub 2023 Sep 7. PMID: 37724991; PMCID: PMC10552824. Gils Contreras A, Bonada Sanjaume A, Montero Jaime M, Rabassa Soler A, Sabench Pereferrer F, Molina López A, Becerra Tomás N, Del Castillo Déjardin D, Salas-Salvadó J. Effects of Two Preoperatory Weight Loss Diets on Hepatic Volume, Metabolic Parameters, and Surgical Complications in Morbid Obese Bariatric Surgery Candidates: a Randomized Clinical Trial. Obes Surg. 2018;28(12):3756–3768. doi: 10.1007/s11695-018-3413-7 . PMID: 30109669. Raza FA, Altaf R, Bashir T, Asghar F, Altaf R, Tousif S, Goyal A, Mohammed A, Mohammad MF, Anan M, Ali S. Effect of GLP-1 receptor agonists on weight and cardiovascular outcomes: A review. Medicine (Baltimore). 2024;103(44):e40364. doi: 10.1097/MD.0000000000040364 . PMID: 39496023; PMCID: PMC11537668. Ilanga M, Heard JC, McClintic J, Lewis D, Martin G, Horn C, Khorgami Z, Richards J, Chow GS, Lim RB. Use of GLP-1 agonists in high risk patients prior to bariatric surgery: a cohort study. Surg Endosc. 2023;37(12):9509–9513. doi: 10.1007/s00464-023-10387-1 . Epub 2023 Sep 12. PMID: 37700013. Kindel TL, Wang AY, Wadhwa A, Schulman AR, Sharaiha RZ, Kroh M, et al. American Gastroenterological Association; American Society for Metabolic and Bariatric Surgery; American Society of Anesthesiologists; International Society of Perioperative Care of Patients with Obesity; Society of American Gastrointestinal and Endoscopic Surgeons. Multisociety clinical practice guidance for the safe use of glucagon-like peptide-1 receptor agonists in the perioperative period. Surg Obes Relat Dis. 2024;20(12):1183–1186. doi: 10.1016/j.soard.2024.08.033. Epub 2024 Oct 29. PMID: 39482213. Parrott J, Frank L, Rabena R, Craggs-Dino L, Isom KA, Greiman L. 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(5):727–741. doi: 10.1016/j.soard.2016.12.018. Epub 2017 Jan 19. PMID: 28392254. Saikaly E, Saad MK. Anastomotic Leak in Colorectal Surgery:A Comprehensive Review. Surg Clin J. 2020; 2(4): 1031. Han L, Deng C, Zhao R, Wan Q, Zhang X, Wang X, Chen Y. Excess visceral fat area as an independent risk factor for early postoperative complications in patients with obesity undergoing bariatric surgery. Front Endocrinol (Lausanne). 2023;14:1072540. doi: 10.3389/fendo.2023.1072540 . PMID: 36843597; PMCID: PMC9947141. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 07 Feb, 2026 Read the published version in Obesity Surgery → Version 1 posted Editorial decision: Revision requested 08 Jul, 2025 Reviews received at journal 29 Jun, 2025 Reviewers agreed at journal 20 Jun, 2025 Reviewers agreed at journal 12 Jun, 2025 Reviewers invited by journal 12 Jun, 2025 Editor assigned by journal 11 Jun, 2025 Submission checks completed at journal 06 Jun, 2025 First submitted to journal 03 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6815565","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":470533393,"identity":"e4d67c81-b5b0-49d1-a46e-46ce00d341ff","order_by":0,"name":"John Pickering","email":"data:image/png;base64,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","orcid":"","institution":"Brown University","correspondingAuthor":true,"prefix":"","firstName":"John","middleName":"","lastName":"Pickering","suffix":""},{"id":470533394,"identity":"a3041bbe-b39b-42c0-ba2c-5eea07fdd369","order_by":1,"name":"Marcoandrea Giorgi","email":"","orcid":"","institution":"Brown University","correspondingAuthor":false,"prefix":"","firstName":"Marcoandrea","middleName":"","lastName":"Giorgi","suffix":""},{"id":470533396,"identity":"6bd99053-4aa0-43f3-b826-50d7017e241b","order_by":2,"name":"Emily Ortega-Goddard","email":"","orcid":"","institution":"Brown University","correspondingAuthor":false,"prefix":"","firstName":"Emily","middleName":"","lastName":"Ortega-Goddard","suffix":""},{"id":470533397,"identity":"7af5ec48-c8a9-4afe-81c1-a244e1505d5b","order_by":3,"name":"Andrew Luhrs","email":"","orcid":"","institution":"Brown University","correspondingAuthor":false,"prefix":"","firstName":"Andrew","middleName":"","lastName":"Luhrs","suffix":""}],"badges":[],"createdAt":"2025-06-04 02:53:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6815565/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6815565/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11695-026-08509-4","type":"published","date":"2026-02-07T15:58:54+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":102234918,"identity":"52a0ad36-fa2e-4ce0-a99c-e0828a459170","added_by":"auto","created_at":"2026-02-09 16:14:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":636602,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6815565/v1/18d7f293-891b-4f8e-8478-8d6d437cbe77.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Extensive weight loss prior to bariatric surgery is associated with worse outcomes","fulltext":[{"header":"Key Points","content":"\u003cp\u003e\u0026bull; Over 10% preoperative weight loss is associated with an increased risk of complications after bariatric surgery\u003c/p\u003e\u003cp\u003e\u0026bull; Complications include higher rates of reoperation, bleeding, emergency department visits, and dehydration\u003c/p\u003e\u003cp\u003e\u0026bull; Limited weight loss (5\u0026ndash;10%) preoperatively may be beneficial to improve the ease of surgery by reducing liver size and visceral fat volume\u003c/p\u003e\u003cp\u003e\u0026bull; Multidisciplinary support optimizes outcomes and mitigates malnutrition risks\u003c/p\u003e"},{"header":"Introduction","content":"\u003cp\u003eOver the past few decades, the escalating prevalence of obesity has emerged as a significant health challenge. Obesity has been shown to reduce life expectancy by 5 to 20 years.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e Obesity is closely associated with various comorbidities, including type 2 diabetes mellitus, cardiovascular disease, joint disease, various types of cancer, and an elevated risk of mortality over time.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e Furthermore, obesity negatively impacts self-reported quality of life and overall well-being.\u003c/p\u003e \u003cp\u003eNonsurgical treatments for severe obesity often yield unsatisfactory outcomes, particularly in the long term. Conversely, bariatric surgery has been shown to not only lead to durable weight loss but to decrease the risk of cardiovascular disease, type 2 diabetes mellitus, and cancer. Bariatric surgery also decreases mortality, with a prospective trial illustrating a reduced overall mortality of 29% over a mean follow-up of 10.9 years.\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eShort-term preoperative weight loss (2\u0026ndash;12 weeks) before bariatric surgery serves multiple purposes, including evaluating patient compliance and aiding in patient selection.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e The primary objective of preoperative weight loss is to enhance the technical ease of the surgery by reducing liver volume and visceral fat volume, which is thought to improve operative exposure and decrease surgical complexity.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e Prerequisite weight loss before bariatric surgery is often mandated by insurance companies.\u003c/p\u003e \u003cp\u003eThe effects of short-term preoperative weight loss (2\u0026ndash;12 weeks) on surgical outcomes remain inconclusive. Several studies have reported benefits, including decreased 30-day complication rates,\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e shorter operative times,\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e and shorter length of stay.\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e Benotti et al showed that 10% preoperative weight loss was associated with fewer complications after gastric bypass surgery.\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eConversely, other studies have found negative outcomes after preoperative weight loss. One study found preoperative weight loss to be associated with an increased risk for malnutrition and infection.\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e In an observational study, pre-operative weight loss was not associated with improved postoperative weight loss, comorbidity resolution at 1 year, or lower 30- or 90-day re-admission rates.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e In a retrospective review of 1,432 bariatric surgery patients, insurance-mandated pre-operative weight-loss programs were not associated with better outcomes at 2 years.\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e In fact, Keith et al found that insurance-mandated pre-operative diets delay treatment and adversely affect weight outcomes.\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eBecause of this conflicting data, there has been long-standing uncertainty and debate regarding the value of preoperative weight loss as a requirement for primary bariatric surgery. Exact preoperative weight loss requirements vary among patients, physicians, hospitals, and health insurance payers. Based on the available evidence, the American Society for Metabolic and Bariatric Surgery (ASMBS) issued a position in 2016 stating that there is no definitive evidence that preoperative weight loss significantly impacts postoperative outcomes.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e Current clinical guidelines by the ASMBS do not recommend preoperative weight loss.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e There is a critical need to clarify the potential influence of preoperative weight loss on postoperative outcomes.\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThis retrospective review aims to investigate the complication rate of patients with greater than 10% preoperative weight loss before primary bariatric surgery compared to those with less than 10% preoperative weight loss.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e The present study conducted a retrospective review utilizing publicly available Participant Use Data File (PUF) from 1,318,808 patients who had undergone primary bariatric surgery (Sleeve Gastrectomy or Roux en Y Gastric Bypass) between the years 2015 and 2021 in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). This program, encompassing more than 90% of all bariatric surgery programs in the United States and Canada, served as the primary data source for this investigation. The data utilized is publicly available and anonymous MBSAQIP data, which does not require Institutional Review Board (IRB) approval.\u003c/p\u003e \u003cp\u003eThe study examined the impact of preoperative weight loss on postoperative outcomes following bariatric surgery. Clinical and demographic data were collected at all participating institutions adhering to a standardized protocol. Data analysis was conducted from August 2023 to March 2024.\u003c/p\u003e \u003cp\u003eThe inclusion criteria included patients\u0026thinsp;\u0026gt;\u0026thinsp;18 years old who underwent Roux en Y gastric bypass or sleeve gastrectomy as primary bariatric surgery. Exclusion criteria included patients who underwent biliopancreatic diversion with duodenal switch, single anastomosis duodenoileostomy (SADI), revisional procedures, and patients lacking documented preoperative weight loss or postoperative complications. Preoperative weight loss was defined as the patient\u0026rsquo;s weight immediately before surgery relative to their highest documented weight.\u003c/p\u003e \u003cp\u003eBaseline weight is defined as the highest weight documented preoperatively. Preoperative weight loss (%preopWL) was defined as baseline weight minus weight on the day of the bariatric procedure divided by the baseline weight.\u003c/p\u003e \u003cp\u003eThe data abstracted from each patient included the procedure type, age, baseline patient demographics, highest weight, weight immediately before surgery, co-morbid conditions including smoking, diabetes mellitus (DM), hypertension (HTN), obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD) and 30 day postoperative outcomes (mortality, reoperation, readmission, sepsis, bleed, etc).\u003c/p\u003e \u003cp\u003eA multivariable regression analysis was performed for the patients\u0026rsquo; preoperative weight loss, controlling for procedure type, DM, ASA\u0026thinsp;\u0026gt;\u0026thinsp;=\u0026thinsp;3, HTN, HLD, COPD, OSA, GERD, smoking, Dialysis, PCI, and MI.\u003c/p\u003e \u003cp\u003eStatistical analysis was performed using STATA software version 14.2 (StataCorp LLC, College Station, TX). Quantitative variables were reported as means with 95% confidence intervals (CI), and descriptive categorical variables were reported as frequencies and proportions. Univariate analysis using \u003cem\u003et-\u003c/em\u003etest or Chi-Square test was used to compare demographic, operative characteristics, and postoperative outcomes between groups. Statistical significance was set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e1,318,808 patients were included in the retrospective review using the MBSAQIP database from January 2015 to December 2021. The \u0026gt;\u0026thinsp;10% weight loss group included 97,861 patients, and the \u0026lt;\u0026thinsp;10% weight loss group included 1,220,947 patients. The average age of the patients was 46 years old in the \u0026gt;\u0026thinsp;10% weight loss group and 44 years old in the \u0026lt;\u0026thinsp;10% weight loss group. The average highest weight was 125.1 kg in the \u0026gt;\u0026thinsp;10% weight loss group and 122.0 kg in the \u0026lt;\u0026thinsp;10% weight loss group. The closest weight immediately before surgery was 99.3 kg in the \u0026gt;\u0026thinsp;10% weight loss group and 123.8 kg in the \u0026lt;\u0026thinsp;10% weight loss group. 6.15% of patients in the \u0026gt;\u0026thinsp;10% weight loss group were smokers and 7.94% of the patients in the \u0026lt;\u0026thinsp;10% weight loss group were smokers (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Of the patients in the \u0026gt;\u0026thinsp;10% weight loss group, 67.34% underwent a sleeve gastrectomy and 32.66% underwent a Roux en Y gastric bypass. Of the patients in the \u0026lt;\u0026thinsp;10% weight loss group, 72.75% underwent a sleeve gastrectomy and 27.25% underwent a Roux en Y gastric bypass (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline Characteristics of Patients Included in Review\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatient factors\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage Age\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHighest Weight (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e125.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e122.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWeight Prior to Surgery (kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e99.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e123.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.15%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.94%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHTN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.86%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.45%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOSA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.10%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.55%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGERD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34.18%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.66%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.62%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.50%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHLD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.27%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.76%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCOPD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.02%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.42%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDialysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.33%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.31%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.291\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASA\u0026thinsp;\u0026gt;\u0026thinsp;=\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e79.81%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78.46%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePCI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.94%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.72%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePulm Emb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.12%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.11%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.495\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.30%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.17%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eHTN\u0026thinsp;=\u0026thinsp;hypertension; OSA\u0026thinsp;=\u0026thinsp;obstructive sleep apnea; GERD\u0026thinsp;=\u0026thinsp;gastroesophageal reflux disease; DM\u0026thinsp;=\u0026thinsp;diabetes mellitus; HLD\u0026thinsp;=\u0026thinsp;hyperlipidemia; COPD\u0026thinsp;=\u0026thinsp;chronic obstructive pulmonary disease; ASA\u0026thinsp;=\u0026thinsp;American Society of Anesthesiology class; PCI\u0026thinsp;=\u0026thinsp;percutaneous coronary intervention; Pulm Emb\u0026thinsp;=\u0026thinsp;pulmonary embolism; MI\u0026thinsp;=\u0026thinsp;myocardial infarction\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eProcedure Performed\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedure Performed\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSleeve Gastrectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e65,896 (67.34%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e888,193 (72.75%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRoux en Y Gastric Bypass\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e31,965 (32.66%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e332,754 (27.25%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePatients who lost more than 10% of their highest preoperative weight were more likely to experience postoperative complications, including reoperation (1.40% vs 1.21%, p\u0026thinsp;\u0026lt;\u0026thinsp;.001), bleeding (0.85% vs 0.67%, p\u0026thinsp;\u0026lt;\u0026thinsp;.001), emergency department visits (7.11% vs 6.57%, p\u0026thinsp;\u0026lt;\u0026thinsp;.001), and dehydration (3.92% vs 3.61%, p\u0026thinsp;\u0026lt;\u0026thinsp;.001) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). These differences remained significant with multivariable regression analysis controlling for multiple patient factors and procedure type (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Patients who lost more than 10% of their highest preoperative weight were also found to have a lower mortality (0.10% vs 0.08%, p\u0026thinsp;=\u0026thinsp;.04) and readmission (3.92% vs 3.60%, p\u0026thinsp;\u0026lt;\u0026thinsp;.001) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). However, after multivariable regression analysis, the mortality rate (OR 0.931, p\u0026thinsp;=\u0026thinsp;.505) and readmission rate (OR 1.022, p\u0026thinsp;=\u0026thinsp;.208) were no longer statistically significant (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e30 day Postoperative Complications after Bariatric Surgery\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplications\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;10% weight loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e93 (0.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e993 (0.08%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReoperation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1373 (1.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14797 (1.21%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReadmission\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3832 (3.92%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e43971 (3.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e11 (0.01%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e254 (0.01%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.54\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBleed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e828 (0.85%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8212 (0.67%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSSI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e84 (0.09%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1056 (0.09%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.947\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eED Visit\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6961 (7.11%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e80239 (6.57%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDehydration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3833 (3.92%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e44053 (3.61%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnastomotic Leak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25 (0.02%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e285 (0.02%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.665\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eSSI\u0026thinsp;=\u0026thinsp;surgical site infection ; ED\u0026thinsp;=\u0026thinsp;Emergency Department\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMultivariable regression analysis of patients with \u0026gt;\u0026thinsp;10% preoperative weight loss controlling for procedure type, DM, ASA\u0026thinsp;\u0026gt;\u0026thinsp;=\u0026thinsp;3, HTN, HLD, COPD, OSA, GERD, Smoking, Dialysis, PCI, MI\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplications\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOdds Ratio\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95% CI Low\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95% CI High\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMortality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.9316131\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.7563367\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.147509\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.505\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReoperation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.069116\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.010896\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.13069\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReadmission\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.02205\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.9879661\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.057309\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.208\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSepsis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.7545072\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0. 4091815\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.391268\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.367\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBleed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.151953\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.071834\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.238061\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSSI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e.8847012\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.7076029\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.106124\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.282\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eED Visit\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.065167\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.038309\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.09272\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDehydration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.080783\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.044856\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.117945\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnastomotic Leak\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.008741\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e.6692509\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.520445\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.967\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eSSI\u0026thinsp;=\u0026thinsp;surgical site infection ; ED\u0026thinsp;=\u0026thinsp;Emergency Department\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePreoperative weight loss before bariatric surgery is often viewed as a strategy to improve the ease of surgery and perioperative risk by decreasing liver size and visceral fat volume.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e Prior analyses have suggested that patients with obesity can lose 10% of their excess body weight in the weeks prior to surgery without significant perioperative risk.\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e However, other studies have shown increased malnutrition and infection rates with excess preoperative weight loss.\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e Several studies have shown that preoperative weight loss is associated with improved surgical outcomes,\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e while others report no reduction in complication rates.\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e Different authors have shown that preoperative weight loss is associated with greater post-surgical total weight loss,\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e while others have shown instead no real benefit.\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e Therefore, further evaluation of the evidence on whether preoperative weight loss leads to improved outcomes is imperative.\u003c/p\u003e \u003cp\u003eDietary restriction prior to surgery is hypothesized to reduce inflammation, improve lipid metabolism, and insulin sensitivity, which supports the importance of continuing investigation towards a well-balanced preoperative treatment program.\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e Different preoperative weight loss approaches may play a critical role in influencing surgical outcomes. Common strategies for preoperative weight loss include protein liquid diets, low-calorie diets (800\u0026ndash;1200 kcals/d), very low-calorie diets (VLCDs) (400\u0026ndash;800 kcals/d), very-low-calorie ketogenic diet, increased physical activity, and the use of pharmacologic agents such as GLP-1 receptor agonists. These diets typically occur 2\u0026ndash;12 weeks prior to surgery and each method varies in its risk profile, effectiveness, and patient adherence. For example, protein liquid diets are simple for patients and are generally well-tolerated, but lack variety which could lead to poor adherence. VLCDs lead to rapid weight loss but increase the risk of malnutrition if not closely monitored.\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e One study by Contreras et al compared an 800 kcal/day VLCD consisting solely of shakes with a 1200 kcal/day diet that incorporated shakes and solid foods.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e The VLCD group achieved greater weight loss while reporting similar adherence levels.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e However, patients in the VLCD group experienced more side effects, including dizziness, fatigue, and weakness.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThe introduction of GLP-1 receptor agonists, such as semaglutide, represents a significant advancement in medical weight loss. These medications have demonstrated efficacy in achieving substantial weight loss while also reducing risks associated with cardiovascular disease and diabetes.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e Their role in preoperative preparation is increasingly being recognized, as they may help patients achieve moderate, controlled weight loss without the nutritional deficiencies that can accompany calorie-restrictive diets.\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eHowever, GLP-1 receptor agonists should be used with caution in the immediate perioperative phase due to the risk of delayed gastric emptying, which can lead to residual gastric contents on the day of the procedure despite traditional fasting.\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e There have been incidents of pulmonary aspiration of gastric contents during sedation or anesthesia in patients taking GLP-1 receptor agonists in the perioperative period.\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e Future studies should explore how the integration of GLP-1 receptor agonists into preoperative bariatric surgery protocols could effect preoperative weight loss as well as surgical outcomes.\u003c/p\u003e \u003cp\u003eSome surgeons may adopt a more stringent approach in counseling patients about preoperative weight loss expectations. This can impact patients\u0026rsquo; nutritional status, either exacerbating malnutrition or influencing their adherence to prescribed weight loss plans. A more aggressive approach may have unintended consequences, such as increasing stress and potentially reducing the likelihood of meeting weight loss goals. Conversely, a more supportive and individualized counseling strategy could help improve patient adherence and nutritional outcomes prior to surgery. Patients who struggle to adhere to a strict preoperative diet should not be excluded from undergoing bariatric surgery, as these diets are designed to improve the technical ease of surgery rather than serve as absolute barriers. It is also important to distinguish preoperative dietary recommendations from insurance-mandated preoperative diet requirements, as they serve different purposes and should not be conflated.\u003c/p\u003e \u003cp\u003eTo ensure patients remain within the optimal preoperative weight loss range, bariatric surgery programs should consider implementing several strategies. Standardized preoperative nutritional assessment and counseling is critical as most patients seeking bariatric surgerу have at least one micronutrient deficiency.\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e A multidisciplinary approach should involving dietitians, behavioral therapists, and surgeons, who can help patients set realistic weight loss goals and adhere to evidence-based dietary plans. Regular monitoring and adjustments (such as weekly or bi-weekly weight measurements and follow-up consultations) can identify deviations early and facilitate early intervention. For patients struggling with dietary compliance or requiring rapid weight loss, pharmacologic agents such as GLP-1 receptor agonists (e.g., semaglutide) should be considered. Finally, revising insurance policies to adopt less rigid weight loss requirements could reduce the pressure for excessive preoperative weight loss, aligning practices with current evidence and ensuring better patient outcomes.\u003c/p\u003e \u003cp\u003eAssessing the effect of preoperative weight loss on perioperative complication rates is difficult, given the overall low incidence of bariatric surgery complications and, consequently, the large study population needed to reach statistical significance. The current mortality and major complication rates of bariatric surgery of less than 0.3% and less than 3%, respectively.\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e The major strength of this review lies in the large study population.\u003c/p\u003e \u003cp\u003eIn this study, patients with greater than 10% preoperative weight loss experienced an increased incidence of several postoperative complications, potentially due to altered physiology resulting from significant weight reduction. The reoperation rate (1.40% vs. 1.21%) may be due to impaired tissue healing as a result of malnutrition from rapid weight loss.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e Similarly, the higher readmission rate (3.92% vs. 3.60%) may be attributed to an increased risk of postoperative infections or nutritional deficiencies, which are commonly observed in patients experiencing rapid weight loss. The bleeding rate (0.85% vs. 0.67%) is also higher, which may result from a variety of factors, including altered coagulation profiles, nutritional deficiencies, and possibly more fragile tissue after significant weight loss, though additional variables such as surgical technique or comorbidities could also contribute. Increased emergency department visits (7.11% vs. 6.57%) could stem from dehydration, electrolyte imbalances, sarcopenia, or gastrointestinal issues, which are more common in this group. Dehydration (3.92% vs. 3.61%) is more prevalent due to electrolyte and fluid imbalances following significant weight loss. However, many complications, such as sepsis, surgical site infections, and anastomotic leaks, were not statistically significant between the groups, highlighting that the overall impact of preoperative weight loss may not be as pronounced for some adverse outcomes.\u003c/p\u003e \u003cp\u003eThe implications of our study may be applicable for other abdominal surgeries as well. In cases that involve a bowel anastomosis, it is well documented that malnutrition is associated with worse outcomes.\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e However, excess visceral fat has also been associated with longer operative time and longer lengths of stay, as well as increased wound infections and increased overall complication rates.\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e This database review demonstrates that greater than 10% of preoperative weight loss is associated with a variety of surgical complications postoperatively.\u003c/p\u003e \u003cp\u003eGiven the retrospective nature of the review, the findings in this study will require further evaluation, such as a randomized, prospective trial.\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eThe limitations of this study are in large part due to the retrospective design. One inherent limitation of the PUF data was the inability to account for the different time intervals over which the preoperative weight loss occurred between patients. The specific methods used for preoperative weight loss are also unknown and presumably vary widely across centers; these include fixed diets, use of weight loss medications, exercise regimens, and more, all of which are likely influential in the outcomes data measured.\u003c/p\u003e \u003cp\u003eThe demographic differences between the two groups in this study may have contributed to the observed outcomes. Patients in the \u0026gt;\u0026thinsp;10% preoperative weight loss group were older and presented with higher rates of some of the obesity-related comorbidities such as hypertension, obstructive sleep apnea, and diabetes mellitus. These factors likely indicate a population with more advanced disease and potentially less physiological reserve, which could predispose them to worse postoperative outcomes. Additionally, these comorbidities may influence surgeons' decisions to pursue more aggressive weight loss strategies preoperatively, potentially introducing selection bias. The patients in the \u0026gt;\u0026thinsp;10% weight loss group were also more likely to have a Roux en Y gastric bypass compared to the \u0026lt;\u0026thinsp;10% weight loss group (32.66% vs 27.25%), which could have contributed to the findings. However, regression analysis was performed and validated these findings (with the exception of the mortality rate and readmission rate) supporting the robustness of our results despite potential confounding factors.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eWhile limited weight loss (5\u0026ndash;10%) prior to bariatric surgery may be beneficial, over 10% preoperative weight loss is associated with worse outcomes in the early postoperative period, including dehydration, bleeding, ED visits, and reoperation. Therefore, excessive preoperative weight loss should be avoided. To optimize preoperative weight loss, we recommend multidisciplinary preoperative support including a nutritional treatment program as well as additional weight measurement on the day of surgery.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003e%preopWL\u003c/strong\u003e: Percentage preoperative weight loss\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eASA\u003c/strong\u003e: American Society of Anesthesiologists\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eASMBS\u003c/strong\u003e: American Society for Metabolic and Bariatric Surgery\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCI\u003c/strong\u003e: Confidence Interval\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCOPD\u003c/strong\u003e: Chronic Obstructive Pulmonary Disease\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eDM\u003c/strong\u003e: Diabetes Mellitus\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eED\u003c/strong\u003e: Emergency Department\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eGERD\u003c/strong\u003e: Gastroesophageal Reflux Disease\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHLD\u003c/strong\u003e: Hyperlipidemia\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHTN\u003c/strong\u003e: Hypertension\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMBSAQIP\u003c/strong\u003e: Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMI\u003c/strong\u003e: Myocardial Infarction\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePCI\u003c/strong\u003e: Percutaneous Coronary Intervention\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePUF\u003c/strong\u003e: Participant Use Data File\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePulm Emb\u003c/strong\u003e: Pulmonary Embolism\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSSI\u003c/strong\u003e: Surgical Site Infection\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eVLCDs\u003c/strong\u003e: Very Low-Calorie Diets\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflicts of Interest\u003cbr\u003e\u003c/strong\u003eThe authors declare that they have no conflicts of interest relevant to this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of generative AI and AI-assisted technologies in the writing process\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDuring the preparation of this work the author used AI in order to improve language and readability, with caution. After using this tool, the author reviewed and edited the content as needed and take full responsibility for the content of the publication.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eJ.P. drafted the main manuscript text. A.L. was responsible for data preparation and contributed to data analysis and interpretation. M.G., E.O., and A.L. provided substantial contributions in reviewing the manuscript and provided critical revisions to the text. All authors approved the final version for submission.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eProspective Studies Collaboration; Whitlock G, Lewington S, Sherliker P, Clarke R, Emberson J, Halsey J, et al. Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. Lancet. 2009;373(9669):1083\u0026ndash;96. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(09)60318-4\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(09)60318-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2009 Mar 18. PMID: 19299006; PMCID: PMC2662372.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBuchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292(14):1724-37. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jama.292.14.1724\u003c/span\u003e\u003cspan address=\"10.1001/jama.292.14.1724\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Erratum in: JAMA. 2005;293(14):1728. PMID: 15479938.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarlsson LMS, Sj\u0026ouml;holm K, Jacobson P, Andersson-Assarsson JC, Svensson PA, Taube M, et al. Life Expectancy after Bariatric Surgery in the Swedish Obese Subjects Study. N Engl J Med. 2020;383(16):1535\u0026ndash;1543. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1056/NEJMoa2002449\u003c/span\u003e\u003cspan address=\"10.1056/NEJMoa2002449\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 33053284; PMCID: PMC7580786.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRomaen IFL, Jense MTF, Palm-Meinders IH, de Witte E, Fransen SAF, Greve JWM, et al. Higher Preoperative Weight loss Is Associated with Greater Weight Loss up to 12 Months After Bariatric Surgery. Obes Surg. 2022;32(9):2860\u0026ndash;2868. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11695-022-06176-9\u003c/span\u003e\u003cspan address=\"10.1007/s11695-022-06176-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2022 Jul 5. PMID: 35788954.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Nieuwenhove Y, Dambrauskas Z, Campillo-Soto A, van Dielen F, Wiezer R, Janssen I, Kramer M, Thorell A. Preoperative very low-calorie diet and operative outcome after laparoscopic gastric bypass: a randomized multicenter study. Arch Surg. 2011;146(11):1300-5. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/archsurg.2011.273\u003c/span\u003e\u003cspan address=\"10.1001/archsurg.2011.273\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 22106323.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEkici U, Ferhatoglu MF. Perioperative and Postoperative Effects of Preoperative Low-Calorie Restrictive Diets on Patients Undergoing Laparoscopic Sleeve Gastrectomy. J Gastrointest Surg. 2020;24(2):313\u0026ndash;319. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11605-019-04157-5\u003c/span\u003e\u003cspan address=\"10.1007/s11605-019-04157-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2019 Feb 20. PMID: 30788716.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoman M, Monaghan A, Serraino GF, Miller D, Pathak S, Lai F, Zaccardi F, Ghanchi A, Khunti K, Davies MJ, Murphy GJ. Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes. Br J Surg. 2019;106(3):181\u0026ndash;189. doi: 10.1002/bjs.11001. Epub 2018 Oct 17. PMID: 30328098.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenotti PN, Still CD, Wood GC, Akmal Y, King H, El Arousy H, et al. Preoperative weight loss before bariatric surgery. Arch Surg. 2009;144(12):1150\u0026ndash;5. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/archsurg.2009.209\u003c/span\u003e\u003cspan address=\"10.1001/archsurg.2009.209\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 20026834; PMCID: PMC4139063.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTewksbury C, Crowley N, Parrott JM, Andromalos L, Isom KA, Smith E, et al. Weight Loss Prior to Bariatric Surgery and 30-Day Mortality, Readmission, Reoperation, and Intervention: an MBSAQIP Analysis of 349,016 Cases. Obes Surg. 2019;29(11):3622\u0026ndash;3628. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11695-019-04041-w\u003c/span\u003e\u003cspan address=\"10.1007/s11695-019-04041-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 31240533.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eConaty EA, Bonamici NJ, Gitelis ME, Johnson BJ, DeAsis F, Carbray JM, Lapin B, Joehl R, Denham W, Linn JG, Haggerty SP, Ujiki MB. Efficacy of a Required Preoperative Weight Loss Program for Patients Undergoing Bariatric Surgery. J Gastrointest Surg. 2016;20(4):667\u0026ndash;73. doi: 10.1007/s11605-016-3093-3. Epub 2016 Feb 10. PMID: 26864165.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHorwitz D, Saunders JK, Ude-Welcome A, Parikh M. Insurance-mandated medical weight management before bariatric surgery. Surg Obes Relat Dis. 2016 Mar-Apr;12(3):496\u0026ndash;499. doi: 10.1016/j.soard.2015.09.004. Epub 2015 Sep 21. PMID: 26775043.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeith CJ Jr, Goss LE, Blackledge CD, Stahl RD, Grams J. Insurance-mandated preoperative diet and outcomes after bariatric surgery. Surg Obes Relat Dis. 2018;14(5):631\u0026ndash;636. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.soard.2018.01.017\u003c/span\u003e\u003cspan address=\"10.1016/j.soard.2018.01.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2018 Feb 2. PMID: 29454535.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim JJ, Rogers AM, Ballem N, Schirmer B; American Society for Metabolic and Bariatric Surgery Clinical Issues Committee. ASMBS updated position statement on insurance mandated preoperative weight loss requirements. Surg Obes Relat Dis. 2016;12(5):955\u0026ndash;959.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun Y, Liu B, Smith JK, Correia MLG, Jones DL, Zhu Z, et al. Association of Preoperative Body Weight and Weight Loss With Risk of Death After Bariatric Surgery. JAMA Netw Open. 2020;3(5):e204803. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jamanetworkopen.2020.4803\u003c/span\u003e\u003cspan address=\"10.1001/jamanetworkopen.2020.4803\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 32407504; PMCID: PMC7225906.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTarnoff M, Kaplan LM, Shikora S. An evidenced-based assessment of preoperative weight loss in bariatric surgery. Obes Surg. 2008;18(9):1059\u0026ndash;61. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11695-008-9603-y\u003c/span\u003e\u003cspan address=\"10.1007/s11695-008-9603-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2008 Jun 28. PMID: 18587621.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHolderbaum M, Casagrande DS, Sussenbach S, Buss C. Effects of very low calorie diets on liver size and weight loss in the preoperative period of bariatric surgery: a systematic review. Surg Obes Relat Dis. 2018;14(2):237\u0026ndash;244. doi: 10.1016/j.soard.2017.09.531. Epub 2017 Oct 2. PMID: 29239795.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStill CD, Benotti P, Wood GC, Gerhard GS, Petrick A, Reed M, et al. Outcomes of preoperative weight loss in high-risk patients undergoing gastric bypass surgery. Arch Surg. 2007;142(10):994-8; discussion 999. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/archsurg.142.10.994\u003c/span\u003e\u003cspan address=\"10.1001/archsurg.142.10.994\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 17938314.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBettini S, Belligoli A, Fabris R, Busetto L. Diet approach before and after bariatric surgery. Rev Endocr Metab Disord. 2020;21(3):297\u0026ndash;306. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11154-020-09571-8\u003c/span\u003e\u003cspan address=\"10.1007/s11154-020-09571-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Erratum in: Rev Endocr Metab Disord. 2020;: PMID: 32734395; PMCID: PMC7455579.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJanssen TAH, Van Every DW, Phillips SM. The impact and utility of very low-calorie diets: the role of exercise and protein in preserving skeletal muscle mass. Curr Opin Clin Nutr Metab Care. 2023;26(6):521\u0026ndash;527. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/MCO.0000000000000980\u003c/span\u003e\u003cspan address=\"10.1097/MCO.0000000000000980\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2023 Sep 7. PMID: 37724991; PMCID: PMC10552824.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGils Contreras A, Bonada Sanjaume A, Montero Jaime M, Rabassa Soler A, Sabench Pereferrer F, Molina L\u0026oacute;pez A, Becerra Tom\u0026aacute;s N, Del Castillo D\u0026eacute;jardin D, Salas-Salvad\u0026oacute; J. Effects of Two Preoperatory Weight Loss Diets on Hepatic Volume, Metabolic Parameters, and Surgical Complications in Morbid Obese Bariatric Surgery Candidates: a Randomized Clinical Trial. Obes Surg. 2018;28(12):3756\u0026ndash;3768. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11695-018-3413-7\u003c/span\u003e\u003cspan address=\"10.1007/s11695-018-3413-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 30109669.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaza FA, Altaf R, Bashir T, Asghar F, Altaf R, Tousif S, Goyal A, Mohammed A, Mohammad MF, Anan M, Ali S. Effect of GLP-1 receptor agonists on weight and cardiovascular outcomes: A review. Medicine (Baltimore). 2024;103(44):e40364. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/MD.0000000000040364\u003c/span\u003e\u003cspan address=\"10.1097/MD.0000000000040364\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 39496023; PMCID: PMC11537668.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIlanga M, Heard JC, McClintic J, Lewis D, Martin G, Horn C, Khorgami Z, Richards J, Chow GS, Lim RB. Use of GLP-1 agonists in high risk patients prior to bariatric surgery: a cohort study. Surg Endosc. 2023;37(12):9509\u0026ndash;9513. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00464-023-10387-1\u003c/span\u003e\u003cspan address=\"10.1007/s00464-023-10387-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Epub 2023 Sep 12. PMID: 37700013.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKindel TL, Wang AY, Wadhwa A, Schulman AR, Sharaiha RZ, Kroh M, et al. American Gastroenterological Association; American Society for Metabolic and Bariatric Surgery; American Society of Anesthesiologists; International Society of Perioperative Care of Patients with Obesity; Society of American Gastrointestinal and Endoscopic Surgeons. Multisociety clinical practice guidance for the safe use of glucagon-like peptide-1 receptor agonists in the perioperative period. Surg Obes Relat Dis. 2024;20(12):1183\u0026ndash;1186. doi: 10.1016/j.soard.2024.08.033. Epub 2024 Oct 29. PMID: 39482213.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eParrott J, Frank L, Rabena R, Craggs-Dino L, Isom KA, Greiman L. 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(5):727\u0026ndash;741. doi: 10.1016/j.soard.2016.12.018. Epub 2017 Jan 19. PMID: 28392254.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaikaly E, Saad MK. Anastomotic Leak in Colorectal Surgery:A Comprehensive Review. Surg Clin J. 2020; 2(4): 1031.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHan L, Deng C, Zhao R, Wan Q, Zhang X, Wang X, Chen Y. Excess visceral fat area as an independent risk factor for early postoperative complications in patients with obesity undergoing bariatric surgery. Front Endocrinol (Lausanne). 2023;14:1072540. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3389/fendo.2023.1072540\u003c/span\u003e\u003cspan address=\"10.3389/fendo.2023.1072540\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. PMID: 36843597; PMCID: PMC9947141.\u003c/span\u003e\u003c/li\u003e \u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"obesity-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"obsu","sideBox":"Learn more about [Obesity Surgery](https://link.springer.com/journal/11695)","snPcode":"11695","submissionUrl":"https://submission.springernature.com/new-submission/11695/3","title":"Obesity Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6815565/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6815565/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Weight loss has been shown to favorably affect obesity-related comorbid disease. Prior studies have shown that a 10% preoperative weight loss is associated with fewer complications after gastric bypass surgery. Although the optimal preoperative preparation for bariatric surgery is not standardized, prerequisite weight loss prior to bariatric surgical procedures is often mandated, typically around 10%, and includes a calorie-restrictive preoperative diet.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjectives\u003c/strong\u003e: To evaluate the association between extensive preoperative weight loss and perioperative outcomes in patients undergoing bariatric surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: To determine optimal weight loss prior to bariatric surgery, we compared patients who lost over 10% of their highest weight preoperatively to patients who did not within the MBSAQIP database from 2015-2021, which included over 1.3 million patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: Patients who lost more than 10% of their highest preoperative weight were more likely to experience postoperative complications, including reoperation (1.40% vs 1.21%, p\u0026lt;.001), bleeding (0.85% vs 0.67%, p\u0026lt;.001), emergency department visits (7.11% vs 6.57%, p\u0026lt;.001), and dehydration (3.92% vs 3.61%, p\u0026lt;.001). These differences remained significant with multivariable regression analysis controlling for multiple patient factors and procedure type.\u003c/p\u003e\n\u003cp\u003ePatients who lost more than 10% of their highest preoperative weight were also found to have a lower mortality (0.10% vs 0.08%, p=.04) and readmission (3.92% vs 3.60%, p\u0026lt;.001), however on multivariable regression analysis these findings were not found to be statistically significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: While preoperative weight loss prior to bariatric surgery may be beneficial, , over 10% preoperative weight loss is associated with worse outcomes and should be avoided.\u003c/p\u003e","manuscriptTitle":"Extensive weight loss prior to bariatric surgery is associated with worse outcomes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-16 07:49:12","doi":"10.21203/rs.3.rs-6815565/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-08T20:48:48+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-29T17:52:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"30163016305515940636879586187584314683","date":"2025-06-20T12:15:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"336747491729239363957541207627751152611","date":"2025-06-12T18:01:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-12T16:31:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-11T12:53:56+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-06T04:10:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Obesity Surgery","date":"2025-06-04T02:51:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"obesity-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"obsu","sideBox":"Learn more about [Obesity Surgery](https://link.springer.com/journal/11695)","snPcode":"11695","submissionUrl":"https://submission.springernature.com/new-submission/11695/3","title":"Obesity Surgery","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"f96e2a94-8279-4171-807a-16aef5b4f314","owner":[],"postedDate":"June 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-09T16:05:23+00:00","versionOfRecord":{"articleIdentity":"rs-6815565","link":"https://doi.org/10.1007/s11695-026-08509-4","journal":{"identity":"obesity-surgery","isVorOnly":false,"title":"Obesity Surgery"},"publishedOn":"2026-02-07 15:58:54","publishedOnDateReadable":"February 7th, 2026"},"versionCreatedAt":"2025-06-16 07:49:12","video":"","vorDoi":"10.1007/s11695-026-08509-4","vorDoiUrl":"https://doi.org/10.1007/s11695-026-08509-4","workflowStages":[]},"version":"v1","identity":"rs-6815565","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6815565","identity":"rs-6815565","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}