Effect of weight-loss diets prior to elective surgery on postoperative outcomes in obesity: a systematic review and meta-analysis
Open accessAbstract
This systematic review investigated the effects of weight-loss diets before elective surgery on preoperative weight loss and postoperative outcomes in people with obesity. Electronic databases were searched from inception to May 2021. Inclusion criteria were prospective cohort or randomised controlled studies that compared effects of weight-loss diets to standard care on postoperative outcomes in adults with obesity awaiting surgery. Participants with cancer or undergoing bariatric surgery were excluded. Data on preoperative weight change, length of stay, postoperative complications and patient-reported outcome measures were extracted and synthesised in meta-analyses. One randomised controlled trial involving total knee arthroplasty and two that investigated general surgery were eligible that included 173 participants overall. Each study compared low-calorie diets using meal replacement formulas to usual care. There is very-low-quality evidence of a statistically significant difference favouring the intervention for preoperative weight loss (mean difference [MD] -6.67 kg, 95% confidence interval [CI] -12.09 to -1.26 kg; p = 0.02) and low-quality evidence that preoperative weight-loss diets do not reduce postoperative complications to 30 days (odds ratio [OR] 0.34, 95% CI 0.08-1.42; p = 0.14) or length of stay (MD -3.72 h, 95% CI -10.76 to 3.32; p = 0.30). From the limited data that is of low quality, weight loss diets before elective surgery do not reduce postoperative complications.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Evidence from bariatric surgery cohorts suggests that weight loss before surgery is linked to better long-term outcomes, including lower postoperative complication rates, improved weight maintenance, and enhanced metabolic control.
“Further, evidence from bariatric surgery cohorts suggests that weight loss before surgery is linked to better long-term outcomes, including lower postoperative complication rates, improved weight maintenance, and enhanced metabolic control.53,54”
From Evaluation of safety of preoperative GLP-1 receptor agonists in patients undergoing elective surgery: a systematic review, meta-analysis and meta-regression (2025) · cites this paper as [53]
Preoperative weight loss has been associated with improved intraoperative technical performance, enhanced visualisation, and reduced operative time.
“Preoperative weight loss has been associated with improved intraoperative technical performance, enhanced visualisation, and reduced operative time.52,53”
From Evaluation of safety of preoperative GLP-1 receptor agonists in patients undergoing elective surgery: a systematic review, meta-analysis and meta-regression (2025) · cites this paper as [53]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA statement
Moher, D., Liberati, A., Tetzlaff, J., Altman, D. G., & for the PRISMA Group (2009) · BMJ · doi:10.1136/bmj.b2535 · Cited by 83,823 · see citing works
Preferred reporting items for systematic reviews and meta-analyses: the PRISMA Statement.
(2009) · PubMed Central · Cited by 44,859 · see citing works
RoB 2: a revised tool for assessing risk of bias in randomised trials
Sterne, J. A. C., Savović, J., Page, M. J., Elbers, R. G., Blencowe, N. S., Boutron, I., Cates, C. J., Cheng, H.-Y., Corbett, M. S., Eldridge, S. M., et al. (2019) · BMJ · doi:10.1136/bmj.l4898 · Cited by 33,583 · see citing works
ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions
Sterne, J. A., Hernán, M. A., Reeves, B. C., Savović, J., Berkman, N. D., Viswanathan, M., Henry, D., Altman, D. G., Ansari, M. T., Boutron, I., et al. (2016) · BMJ · doi:10.1136/bmj.i4919 · Cited by 20,329 · see citing works
Analysing Data and Undertaking Meta‐Analyses
Deeks, J. J., Higgins, J. P., & Altman, D. G. (2008) · Cochrane Handbook for Systematic Reviews of Interventions · doi:10.1002/9780470712184.ch9 · Cited by 1,800 · see citing works
Mullen, J. T., Moorman, D. W., & Davenport, D. L. (2009) · Annals of Surgery · doi:10.1097/sla.0b013e3181ad8935 · Cited by 596 · see citing works
The Influence of Obesity on the Complication Rate and Outcome of Total Knee Arthroplasty
Kerkhoffs, G. M. M. J., Servıen, E., Dunn, W. R., Dahm, D. L., Bramer, J. A. M., & Haverkamp, D. (2012) · Journal of Bone and Joint Surgery · doi:10.2106/jbjs.k.00820 · Cited by 504 · see citing works
Hainer, V., & Aldhoon-Hainerová, I. (2013) · Diabetes Care · doi:10.2337/dcs13-2023 · Cited by 503 · see citing works
Obesity – a risk factor for postoperative complications in general surgery?
Tjeertes, E. K. M., Hoeks, S. E., Beks, S. S. B. J. C., Valentijn, T. M., Hoofwijk, A. G. M., & Stolker, R. J. (2015) · BMC Anesthesiology · doi:10.1186/s12871-015-0096-7 · Cited by 321 · see citing works
The obesity paradox in the surgical population
Valentijn, T. M., Galal, W., Tjeertes, E. K. M., Hoeks, S. E., Verhagen, H. J. M., & Stolker, R. J. (2013) · The Surgeon · doi:10.1016/j.surge.2013.02.003 · Cited by 161 · see citing works
Body Mass Index as a Predictor of Complications and Mortality After Lumbar Spine Surgery
Marquez-Lara, A. J., Nandyala, S. V., Sankaranarayanan, S., Noureldin, M., & Singh, K. (2014) · Spine · doi:10.1097/brs.0000000000000232 · Cited by 157 · see citing works
Inacio, M. C. S., Kritz‐Silverstein, D. C., Raman, R., Macera, C. A., Nichols, J. F., Shaffer, R. A., & Fithian, D. C. (2013) · The Journal of Arthroplasty · doi:10.1016/j.arth.2013.07.030 · Cited by 108 · see citing works
Weight Loss Intervention Before Total Knee Replacement: A 12-Month Randomized Controlled Trial
Liljensøe, A., Laursen, J. O., Bliddal, H., Søballé, K., & Mechlenburg, I. (2019) · Scandinavian Journal of Surgery · doi:10.1177/1457496919883812 · Cited by 80 · see citing works
Time Trends in the Characteristics of Patients Undergoing Primary Total Knee Arthroplasty
Singh, J. A., & Lewallen, D. G. (2013) · Arthritis Care & Research · doi:10.1002/acr.22233 · Cited by 77 · see citing works
Morbid Obesity and Lumbar Fusion in Patients Older Than 65 Years
Puvanesarajah, V., Werner, B. C., Cancienne, J. M., Jain, A., Pehlivan, H. C., Shimer, A. L., Singla, A., Shen, F. H., & Hassanzadeh, H. R. (2016) · Spine · doi:10.1097/brs.0000000000001692 · Cited by 72 · see citing works
Inacio, M. C. S., Kritz‐Silverstein, D. C., Raman, R., Macera, C. A., Nichols, J. F., Shaffer, R. A., & Fithian, D. C. (2014) · The Bone & Joint Journal · doi:10.1302/0301-620x.96b5.33136 · Cited by 69 · see citing works
Roman, M., Monaghan, A., Serraino, G. F., Miller, D., Pathak, S., Lai, F., Zaccardi, F., Ghanchi, A., Khunti, K. K., Davies, M. J., et al. (2018) · British journal of surgery · doi:10.1002/bjs.11001 · Cited by 53 · see citing works
Naylor, J., Harmer, A. R., & Heard, R. C. (2008) · Australian Journal of Physiotherapy · doi:10.1016/s0004-9514(08)70067-9 · Cited by 49 · see citing works
Self-citationThe Cost of Obesity for Nonbariatric Inpatient Operative Procedures in the United States
Mason, R. J., Moroney, J. R., & Berne, T. V. (2013) · Annals of Surgery · doi:10.1097/sla.0b013e3182a500ce · Cited by 47 · see citing works
Burnand, K. M., Lahiri, R. P., Burr, N. E., van Rensburg, L. J., & Lewis, M. P. (2016) · HPB · doi:10.1016/j.hpb.2016.01.545 · Cited by 42 · see citing works
Delgado, J. C. L., Esteve, F., Máñez, R., Torrado, H., Carrió, M. L., Rodríguez-Castro, D., Farrero, E., Javierre, C. F., Skaltsa, K., & Ventura, J. L. (2015) · PLoS ONE · doi:10.1371/journal.pone.0118858 · Cited by 38 · see citing works
Gandler, N., Simmance, N., Keenan, J., Choong, P., & Dowsey, M. M. (2016) · Obesity Research & Clinical Practice · doi:10.1016/j.orcp.2016.03.006 · Cited by 37 · see citing works
Grundmann, F., Müller, R., Reppenhorst, A., Hülswitt, L., Späth, M. R., Kubacki, T., Scherner, M. P., Faust, M., Becker, I., Wahlers, T., et al. (2018) · Journal of the American Heart Association · doi:10.1161/jaha.117.008181 · Cited by 36 · see citing works
Hollis, G., Franz, R., Bauer, J. D., & Bell, J. (2020) · Nutrition & Dietetics · doi:10.1111/1747-0080.12601 · Cited by 28 · see citing works
Jongbloed, F., de Bruin, R. W. D., Klaassen, R., Beekhof, P., van Steeg, H., Dor, F., van der Harst, E., Dollé, M., & Ijzermans, J. (2016) · Nutrients · doi:10.3390/nu8050306 · Cited by 26 · see citing works
Pellegrini, C. A., Chang, R. W., Dunlop, D. D., Conroy, D. E., Lee, J. J., Horn, L. V., Spring, B. J., & Cameron, K. A. (2018) · Obesity Research & Clinical Practice · doi:10.1016/j.orcp.2018.06.009 · Cited by 18 · see citing works
de Luis, D. A., Izaola, O., Alonso, M. G., Aller, R., Cabezas, G., & de la Fuente, B. (2012) · PubMed · Cited by 17 · see citing works
Evaluation of Preoperative Weight Loss for Elective Hernia Repair in the Veteran Population
Sun, B. J., Valdez, D., Duong, D., Gupta, R., & Smith, B. R. (2017) · The American Surgeon · doi:10.1177/000313481708301020 · Cited by 12 · see citing works
Weight loss for obese patients prior to total knee replacement
Borland, W. S., & Jennings, A. (2011) · Journal of Clinical Orthopaedics and Trauma · doi:10.1016/s0976-5662(11)60059-3 · Cited by 3 · see citing works
Very Low-Calorie Diet in Cardiac Surgery Patients With Obesity and Metabolic Syndrome
Vo, T., Marney, L., Mundy, J. A., Edney, G., & Griffin, R. (2019) · Heart Lung and Circulation · doi:10.1016/j.hlc.2019.02.140 · Cited by 1 · see citing works
Flagged first, then by citations
1 of the 31 references couldn’t be matched to a known paper.
Research works printed but not linked: 3
- [9]Smokers And Overweight Patients: Soft Targets For NHS Savings? England: The Royal College of Surgeons of England; 2016:1‐27. Accessed July 12, 2021. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/smokers-soft-targets/
- [10]Griffin S. Implementation of a Model of Care for Obese Patients Requiring Weight Loss Prior to Elective Surgery. Queensland: Clinical Excellence Queensland, Queensland Health; 2021:1‐4. Accessed July 12, 2021. https://clinicalexcellence.qld.gov.au/improvement-exchange/implementation-model-care-obese-patients-requiring-weight-loss-prior-elective
- [16]Review Manager (RevMan) [Computer program]. Version 5.4, The Cochrane Collaboration, 2020.
Cited by
Sorted by citations
Kamarajah, S. K., Gudiozzi, N., Findlay, J. M., Lee, M. J., Pinkney, T., & Markar, S. R. (2025) · eClinicalMedicine · doi:10.1016/j.eclinm.2025.103408 · Cited by 29 · see citing works
The impact of preoperative weight loss timing on surgical outcomes in total hip arthroplasty
Shul, C., Hameed, D., Oster, B., Dubin, J. A., Bains, S. S., Mont, M. A., & Johnson, A. J. (2024) · The Journal of Arthroplasty · doi:10.1016/j.arth.2024.02.075 · Cited by 20 · see citing works
Luca, M. D., Zese, M., Bandini, G., Zappa, M. A., Bardi, U., Carbonelli, M. G., Carrano, F. M., Casella, G., Chianelli, M., Chiappetta, S., et al. (2024) · Updates in Surgery · doi:10.1007/s13304-024-01996-z · Cited by 16 · see citing works
Pavlovic, N., Naylor, J., Boland, R. A., Harris, I. A., Flood, V. M., Genel, F., Gao, M., Hackett, D., Vleeskens, C., & Brady, B. (2023) · Journal of Clinical Nursing · doi:10.1111/jocn.16841 · Cited by 8 · see citing works
Self-citationWeight Loss Before Total Knee Arthroplasty Was Not Associated with Decreased Postoperative Risks
Seward, M. W., Grimm, J. A., Hannon, C. P., Bedard, N. A., Berry, D. J., & Abdel, M. P. (2025) · Journal of Bone and Joint Surgery · doi:10.2106/jbjs.25.00061 · Cited by 5 · see citing works
Lim, J. Z. M., Williams, A., Burgess, J., O'Connell, J., James, M., Cross, A., Hughes, D. M., Cuthbertson, D. J., Alam, U., & Wilding, J. P. H. (2024) · Clinical Obesity · doi:10.1111/cob.12703 · Cited by 5 · see citing works
Zhang, Y., Bellafronte, N. T., Najafitirehshabankareh, G., Jimenez, M. H., Jaeger-McEnroe, E., Plourde, H., Hendrickson, M., & Gillis, C. (2024) · European Journal of Surgical Oncology · doi:10.1016/j.ejso.2024.108743 · Cited by 4 · see citing works
Nutritional Considerations in Hip and Knee Arthroplasty
Arapovic, A. E., Nham, F. H., Darwiche, H. F., & El‐Othmani, M. M. (2024) · JBJS Reviews · doi:10.2106/jbjs.rvw.24.00033 · Cited by 4 · see citing works
Gosavi, R., Rasooli, M. A., Leon, N., Sivayogan, K., Koh, D., Hong, J. T., Narasimhan, V., & Ooi, G. (2026) · Journal of Gastrointestinal Cancer · doi:10.1007/s12029-026-01405-1 · Cited by 3 · see citing works
Prompting lifestyle interventions to promote weight loss is safe, effective and patient-centred: No
Ballantyne, A., Steers, D., & Gray, L. (2023) · Journal of Primary Health Care · doi:10.1071/hc23163 · Cited by 3 · see citing works
Stanton, E. W., Manasyan, A., Boudiab, E. M., Carey, J. N., & Daar, D. A. (2024) · Microsurgery · doi:10.1002/micr.31231 · Cited by 2 · see citing works
Yang, B., Lavigne, A., Carugo, D., Turney, B. W., Somani, B. K., & Stride, E. (2024) · Current Opinion in Urology · doi:10.1097/mou.0000000000001208 · Cited by 1 · see citing works
Total hip arthroplasty in the context of obesity
McCann, C. J., Morrison, S. R., Hall, A. J., & Dunstan, E. (2025) · Orthopaedics and Trauma · doi:10.1016/j.mporth.2025.11.005 · Cited by 1 · see citing works
Wang, D., Buczacki, S. J. A., Gu, Q., Liao, Z., Jiang, Y., West, S., & Koutoukidis, D. A. (2025) · BJS Open · doi:10.1093/bjsopen/zrag001 · Cited by 1 · see citing works
The Outcome of Reduction Mammoplasty for Gigantomastia Using Inferior Pedicle: Case Series
Yiltok, S. J., Akintayo, A. J., Choji, J. D., Karago, C. Y., & Orkar, K. S. (2024) · Nigerian Journal of Clinical Practice · doi:10.4103/njcp.njcp_427_24
Tupper, L., Morley, S., & Utter, J. (2025) · Musculoskeletal Care · doi:10.1002/msc.70146
Prise en charge du surpoids et de l’obésité en préopératoire
Pardo, E. (2026) · Le Praticien en Anesthésie Réanimation · doi:10.1016/j.pratan.2026.02.007
Sarasombath, P., Gajaseni, P., Khorana, J., & Atthakomol, P. (2026) · European Spine Journal · doi:10.1007/s00586-026-09966-2
McCann, C. J., Clement, N., Murray, A. D., Kearney, R., Madigan, S. M., Gee, C. W., Walmsley, P., Morrison, S. R., Chopra, S., & Hall, A. J. (2026) · British Journal of Sports Medicine · doi:10.1136/bjsports-2025-111225
Coates, T., Bak, M., Rajagopalan, A., Pesevski, F., Ravi, A., Croagh, D., & Ooi, G. (2026) · World Journal of Surgery · doi:10.1002/wjs.70470
Lau, L. C., Lui, T. W. D., Wen, C., Zhu, L., Lin, S., Leung, T. K. C., Luk, M. H., Ping Keung, C. H. A. N., Cheung, A., Chiu, K. Y., et al. (2026) · Bone & Joint Open · doi:10.1302/2633-1462.77.bjo-2025-0359.r1
Leivaditis, V., Mulita, F., Koletsis, E. N., Androutsopoulou, V. A., Baikoussis, N. G., Mitsos, S., Papatriantafyllou, A., Tomos, P., & Dahm, M. (2026) · British Journal of Hospital Medicine · doi:10.31083/bjhm57290
- Authors
- Pavlovic, N., Boland, R. A., Brady, B., Genel, F., Harris, I. A., Flood, V. M., & Naylor, J. M.
- Affiliations
- Fairfield Hospital (AU)
- The University of Sydney (AU)
- UNSW Sydney (AU)
- Liverpool Hospital (AU)
- Corresponding author
- Pavlovic, Natalie
- ORCID
- Venue
- Clinical Obesity
- Publisher
- Wiley
- Published
- 2021-08-31
- Volume
- 11
- Issue
- 6
- Pages
- e12485-e12485
- ISSN
- 1758-8103 (ISSN-L)
- 1758-8111
- PMC
- PMC9286439
- OpenAlex
- W3198121312
- Cited by
- 22
- References
- 31
- Citations by year
- 2026: 7 · 2025: 5 · 2024: 8 · 2023: 2
- FWCI
- 0.60
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Clinical Obesity (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Funders
- Medibank Better Health Foundation
- Topics
- Health Sciences › Medicine › Surgery › Bariatric Surgery and Outcomes
- Health Sciences › Medicine › Surgery › Enhanced Recovery After Surgery
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiac, Anesthesia and Surgical Outcomes
- Keywords
- weight loss diet, preoperative weight loss, obesity, elective surgery, postoperative complications, length of hospital stay, hypocaloric diet, total knee arthroplasty, general surgery, patient-reported outcomes
- MeSH terms
- Adult, Diet, Reducing, Humans, Obesity, Postoperative Complications, Prospective Studies, Elective Surgical Procedures
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
