Research

Energy balance

Pre-operative Very Low Energy Diets (VLEDs) used for 14 days may reduce technical difficulty and early complications by reducing liver volume, but do not significantly impact 30-day morbidity or operative time.

A 14-day VLED might make your surgery technically easier by shrinking your liver, but it won't necessarily reduce your overall risk of complications or shorten your operation time. It is a specific tool used in some guidelines, not a general requirement.

ModerateQualifiesMEDIUM confidence
A large multicentre trial found that pre-operative weight loss with a 14-day VLED led to reduced technical difficulty during the surgery and fewer early post-operative complications, although there were no between-group differences in intraoperative complications, blood loss or operative time
Enda Murphy et al. · Metabolism · 2023

Why this rating

Based on a large multicentre trial and a meta-analysis with mixed findings.

Source

Addressing uncertainty about the role of structured lifestyle modification for metabolic surgery patients

Enda Murphy et al. · Metabolism · 2023

DOI 10.1016/j.metabol.2023.155739

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DOI resolved against Crossref · corpus check 2026-06-10

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