Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
The procedure used to remove a gallbladder is called laparoscopic cholecystectomy. This study is investigating whether following a very low calorie diet for 2 weeks prior to a laparoscopic cholecystectomy operation reduces operation time and makes the operation easier. We will also investigate if post-operative complications are reduced as a result of following this diet. The very low calorie diet is used routinely to improve weight loss surgery. The diet causes the liver to shrink and this shrinkage allows the operation to be performed much easier. As the gallbladder is attached to the liver we want to see if this diet can also make a cholecystectomy operation easier.

Who can participate?
Adult patients with a BMI of over 30 who are awaiting a cholecystectomy operation

What does the study involve?
Participants are randomly allocated to one of two groups: very low calorie diet group or normal diet group. The surgeon will not know which group they are in. We will look at how long the operation takes between the two groups. We will also look at the difference between the two groups in weight loss, complication rate after surgery, length of stay after surgery, day case rates and how difficult the operation was from a technical point of view.

What are the possible benefits and risks of participating?
By taking part in this trial participants will be contributing to the advancement of medical knowledge of what is ‘best practice’ for the laparoscopic cholecystectomy procedure. If they are allocated to the low calorie arm they will lose some weight in the short term. Previous research has shown that weight loss reduces the size of the liver, which makes it easier for the surgeon to move the liver out of the way in order to remove the gallbladder. This should make the operation time shorter, and will, we hope, reduce the incidence of complications post-operatively. Previous studies have used low calorie diets for operations to the stomach which have helped to reduce the liver size and make the operation easier. The risks associated with this study are those associated with the operation. The procedure will not be different to the procedure normally carried out for the removal of gallbladders. Disadvantages of this study are that if participants do fall into the group for the low calorie diet, this will mean a lifestyle adjustment for that period. Previous studies have shown that some people may feel light headed or dizzy on this diet especially when standing from a sitting or lying position. Additionally, some people following low calorie diets have felt more tired and some have had more headaches than usual. Participants will be asked to inform the research nurse of any side effects that they have and information on how to do this will be given on the diet sheet.

Where is the study run from?
Norfolk and Norwich University Hospital (UK)

When is the study starting and how long is it expected to run for?
September 2010 to May 2015

Who is funding the study?
Norfolk and Norwich University Hospital (UK)

Who is the main contact?
Mr Michael Lewis

Trial website

Contact information



Primary contact

Mr Michael Lewis


Contact details

Dept of Surgery
Norfolk and Norwich University Hospital
Colney Lane
United Kingdom
+44 (0)1603 287583

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A randomised, single blinded trial, assessing the effect of a two week preoperative very low calorie diet (VLCD) on laparoscopic cholecystectomy procedure in obese patients



Study hypothesis

The aim of this study is to examine the effect of a two week VLCD on laparoscopic cholecystectomy in obese patients. We hypothesize that the reduction in size of the liver will improve surgical access and dissection, reduce operation complexity and ultimately operating time. By reducing operative difficulty, we propose that there will be a reduction in procedure related complications and an increase in the number of day case laparoscopic cholecystectomies.

Ethics approval

Cambridge South, 11/02/2100, ref: 10/H0305/78

Study design

Interventional single-centre prospective randomised trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Obese patients undergoing elective cholecystectomy surgery


Intervention group: two week pre-operative very low calorie diet
Control group: continue normal diet

Intervention type



Drug names

Primary outcome measure

Duration of surgery

Secondary outcome measures

1. Pre-operative weight loss
2. Post operative complication rate
3. Post operative length of stay
4. Post operative day case rate
5. Perceived difficulty of the operation

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Adult patients with capacity to consent
2. Body mass index (BMI) over 30kg/m2
3. Symptomatic gallstone disease placed on a waiting list for elective laparoscopic cholecystectomy operation

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Presence of any pre-existing liver disease
2. Diabetes mellitus
3. Confirmed common bile duct stones
4. Previous abdominal surgery

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Norfolk and Norwich University Hospital
Colney Lane
United Kingdom

Sponsor information


Norfolk and Norwich University Hospital (UK)

Sponsor details

Colney Lane
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Norfolk and Norwich University Hospital (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

We plan to submit the results of the trial at the end of april to the BJS

Intention to publish date

Participant level data

Available on request

Basic results (scientific)

Publication list

2016 results in:

Publication citations

Additional files

Editorial Notes

09/05/2016: Publication reference added.