Plain English Summary
Background and study aims
The aim of this study is to assess which type of dietary strategy is the most effective for patients with morbid obesity who are about to undergo weight loss (bariatric) surgery. It is thought that a low calorie diet will be more effective than a very low calorie diet (e.g. it will reduce surgical complications and length of hospital stay).
Who can participate?
Patients with morbid obesity undergoing bariatric surgery
What does the study involve?
Participants are randomly allocated to follow a very low calorie diet or a low calorie diet for 21 days before surgery. Body measurements, blood parameters, liver volume by CT scan, and compliance with the intervention are measured before and after the intervention.
What are the possible benefits and risks of participating?
In the short term, it is not expected that the results obtained may directly benefit the participant, although they could be of interest for future patients undergoing bariatric surgery. The study does not pose any additional risk apart from providing blood samples and undergoing CT scans.
Where is the study run from?
Hospital Universitari Sant Joan de Reus (Spain)
When is the study starting and how long is it expected to run for?
September 2014 to July 2017
Who is funding the study?
Who is the main contact?
Dr Jordi Salas Salvado
Effects of two preoperatory weight loss diets on hepatic volume and surgical complications in morbid obese bariatric surgery candidates: a randomized clinical trial
Pre-operative weight loss in patients with morbid obesity candidates for bariatric surgery through the use of a Low Calorie Diet (LCD) will be more effective than a Very Low Calorie Diet (VLCD) on the preservation of protein and immune status, reduction of surgical complications, hospital stay and will be equally effective in terms of reduction in liver volume.
Ethical committee of the University Hospital Sant Joan de Reus, 29/01/2015, CEIC reference project: 14-09-18 / 9proj4, reference CEIC esmena: 15-01-29 / 1esmproj1
Single-center randomized parallel trial
Primary study design
Secondary study design
Randomised parallel trial
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Influence of two types of pre-surgery diets on the decrease of hepatomegaly in morbidly obese candidates for bariatric surgery
Subjects will be randomized with a 1:1 ratio using an excel randomization table to follow a very low calorie diet (VLCD) or a low-calorie diet (LCD) for a period of 21 days. Both dietary interventions had the same percentage of macronutrients (46.8% carbohydrates, 36.4% protein, 9.3% fat, and 7.4% fiber). The total amount of energy administered with the VLCD (4 sachets of Optifast®; Nestlé Health Science; 2011) will be 800 kcal/day, broth and non-calorie beverages allowed. The LCD diet consisted of a defined fixed diet containing 1200 kcal/day also using two sachets of Optifast®.
Primary outcome measure
Hepatic volume through computed tomography at baseline and 21 days after dietary intervention
Secondary outcome measures
1. Body weight and anthropometry parameters at baseline and at 21 days of intervention
2. Leukocyte count and serum albumin, prealbumin and total proteins at baseline and at 21 days of intervention
3. Renal and hepatic function parameters at baseline and at 21 days of intervention
4. Surgery complications (between surgery until 6 months after surgery) and hospital stay length (during the hospital stay)
5. Dietary compliance and acceptability, assessed weekly during the first 3 weeks of the intervention
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
BMI ≥ 40 kg/m2 or BMI between 35-40 kg/m2 with associated major comorbidities undergoing bariatric surgery
Target number of participants
80 effectively randomized participants: 40 in each group
Participant exclusion criteria
The same criteria established by hospital protocol for patients undergoing bariatric surgery
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Hospital Universitari Sant Joan de Reus
Avinguda Dr Josep Laporte, 2
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The protocol and statistical plan are not available. Planned publication of the results in a high-impact peer reviewed journal.
IPD sharing statement
The data sharing plans for the current study are unknown and will be made available at a later date.
Intention to publish date
Participant level data
To be made available at a later date
Basic results (scientific)