University of Leicester
Manuscript - The effects of weight loss as a pre-operative lifestyle intervention a systematic review (Resubmission _ Clean Version).pdf (294.09 kB)

Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes.

Download (294.09 kB)
journal contribution
posted on 2019-03-27, 10:04 authored by M Roman, A Monaghan, GF Serraino, D Miller, S Pathak, F Lai, F Zaccardi, A Ghanchi, K Khunti, MJ Davies, GJ Murphy
BACKGROUND: The aim was to investigate whether preoperative weight loss results in improved clinical outcomes in surgical patients with clinically significant obesity. METHODS: This was a systematic review and aggregate data meta-analysis of RCTs and cohort studies. PubMed, MEDLINE, Embase and CINAHL Plus databases were searched from inception to February 2018. Eligibility criteria were: studies assessing the effect of weight loss interventions (low-energy diets with or without an exercise component) on clinical outcomes in patients undergoing any surgical procedure. Data on 30-day or all-cause in-hospital mortality were extracted and synthesized in meta-analyses. Postoperative thromboembolic complications, duration of surgery, infection and duration of hospital stay were also assessed. RESULTS: A total of 6060 patients in four RCTs and 12 cohort studies, all from European and North American centres, were identified. Most were in the field of bariatric surgery and all had some methodological limitations. The pooled effect estimate suggested that preoperative weight loss programmes were effective, leading to significant weight reduction compared with controls: mean difference -7·42 (95 per cent c.i. -10·09 to -4·74) kg (P < 0·001). Preoperative weight loss interventions were not associated with a reduction in perioperative mortality (odds ratio 1·41, 95 per cent c.i. 0·24 to 8·40; I2  = 0 per cent, P = 0·66) but the event rate was low. The weight loss groups had shorter hospital stay (by 27 per cent). No differences were found for morbidity. CONCLUSION: This limited preoperative weight loss has advantages but may not alter the postoperative morbidity or mortality risk.


G.J.M. and F.L. are supported by British Heart Foundation grants RG/13/6/29947 and CH/12/1/29419. M.J.D. and K.K. are National Institute for Health Research (NIHR) Senior Investigators and, along with F.Z. and G.F.S., are supported by the Leicester NIHR Cardiovascular Biomedical Research Centre and the NIHR Collaborative Leadership in Applied Healthcare – East Midlands. G.J.M. reports grants from the British Heart Foundation during the conduct of the study, and grants from the British Heart Foundation, NIHR and Zimmer Biomet, and personal fees from Abbvie and Thrasos, outside the submitted work. M.J.D. and K.K. report grants from the NIHR outside the submitted work.



British Journal of Surgery, 2018, 106(3), pp. 181-189

Author affiliation

/Organisation/COLLEGE OF LIFE SCIENCES/School of Medicine/Department of Cardiovascular Sciences


  • AM (Accepted Manuscript)

Published in

British Journal of Surgery


Wiley for British Journal of Surgery Society



Acceptance date


Copyright date


Available date


Publisher version


The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.



Usage metrics

    University of Leicester Publications


    No categories selected



    Ref. manager