Low-calorie Diet and Body Composition Prior to Roux-en-Y Gastric Bypass (LCD)

The Effect of a 2-week vs. 6-week Low-calorie Diet (LCD) Followed by Roux-en-Y Gastric Bypass (RYGB) on Body Composition and Surgery Outcomes in Obese Humans: a Dietary Intervention and Magnetic Resonance Imaging Study

Losing weight before undergoing Roux-en-Y gastric bypass (RYGB) surgery may reduce liver fat content and size thereby improving surgical outcomes. This study aims to investigate whether a 2-week or 6-week pre-operative liquid formula low-calorie diet (LCD) reduces liver fat further than a conventional food diet prior to RYGB using magnetic resonance imaging (MRI). The hypothesis is that the 2-week and 6-week liquid formula LCD will reduce liver fat further than the conventional food pre-operative diet.

Study Overview

• Status: Completed
• Conditions: Liver Fat; Morbid Obesity
• Intervention / Treatment: Other: Control diet; Dietary supplement: Liquid formula low-calorie diet (LCD); Procedure: Roux-en-Y gastric bypass (RYGB)

Detailed Description

The morbidly obese subjects (BMI higher then 40 kg/m2) were randomised and assessed at baseline (week 0). After 2 weeks on a low-calorie diet (LCD), participants underwent either Roux-en-Y gastric bypass (RYGB) or continued with a LCD for 4 weeks.The participants will reassess at week 6.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Greater London
    • London, Greater London, United Kingdom, W12 0NN
      • Imperial Clinical Research Facility

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• patients undergoing Roux-en-Y gastric bypass at Imperial Weight Centre
• aged 18 to 60 years
• boby mass index of 35 to 55 kg/m2

Exclusion Criteria:

• Claustrophobia
• Pacemaker, metal implant, clips, implanted device, shrapnel or bullets, metal in eyes that precludes magnetic resonance imaging
• Current pregnancy or breast feeding for females (as determined by a pregnancy test)
• A full term pregnancy within the last year for females
• Treatment with any medication that might affect the study outcomes
• Haemorrhagic disorders and anticoagulant treatment
• History of cancer, excluding skin cancer
• History of severe or multiple allergies, severe adverse drug reaction or leucopenia
• Smokers
• Regular drinkers of more than three units of alcohol daily
• History of, or current evidence of, abuse of alcohol or any drug substance, licit or illicit
• Regular intake of over-the-counter (OTC) medication (other than the occasional paracetamol/aspirin)
• Poor compliers or subjects unlikely to commit to the 26 week study duration
• Blood donation within the 12 week period before the initial study dose
• Use of monoamine oxidase inhibitors (MAOIs) as anti depressant

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 2-week LCD and Roux-en-Y gastric bypass (RYGB); A 2-week liquid formula low-calorie diet (LCD) will be administered for 2 weeks prior to Roux-en-Y gastric bypass. The diet will provide 800kcal per day in the form of powdered milkshakes and soups	Dietary supplement: Liquid formula low-calorie diet (LCD); The liquid formula low-calorie diet (LCD) will provide 800kcal/day from powdered milkshakes and soups. The diet will be provided by Cambridge Weight Plan.; Other Names: LCD; LED; Cambridge Weight Plan; Procedure: Roux-en-Y gastric bypass (RYGB); Participant went through Roux-en-Y gastric bypass (RYGB) surgery
Active Comparator: 6-week LCD; A 6-week liquid formula low-calorie diet (LCD) will be administered for 6 weeks prior to Roux-en-Y gastric bypass. The diet will provide 800kcal per day in the form of powdered milkshakes and soups	Dietary supplement: Liquid formula low-calorie diet (LCD); The liquid formula low-calorie diet (LCD) will provide 800kcal/day from powdered milkshakes and soups. The diet will be provided by Cambridge Weight Plan.; Other Names: LCD; LED; Cambridge Weight Plan
Other: Control diet; 1000 calorie diet	Other: Control diet; Procedure: Roux-en-Y gastric bypass (RYGB); Participant went through Roux-en-Y gastric bypass (RYGB) surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Intra-hepatocellular Lipid Content (IHCL) Following the Pre-operative Diet	Intra-hepatocellular lipid content will be measured by magnetic resonance spectroscopy	at 2 weeks or 6 weeks depending on group

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Intra-hepatocellular Lipid Content (IHCL) Following Roux-en-Y Gastric Bypass	Intra-hepatocellular lipid content (IHCL) will be compared between groups at 1 month following Roux-en-Y gastric bypass	at 1-month following Roux-en-Y gastric bypass
Change in Intra-hepatocellular Lipid Content (IHCL) Following Roux-en-Y Gastric Bypass	Intra-hepatocellular lipid content (IHCL) will be compared between groups at 6 months following Roux-en-Y gastric bypass	at 6 months following Roux-en-Y gastric bypass
Complexity of Surgery	Complexity of surgery will be assessed by the surgeon at the time of surgery (either after 2 weeks for the Control group and 2-week LCD group or after 6 weeks for the 6-week LCD group) The complexity of the surgery was assessed through a score on a complexity scale based on questionnaires previously published by Anders Thorell"s and David Edholm"s groups (Edholm et al., 2011, Van Nieuwenhove et al., 2011). The scores (1-5) for 7 variables: exposure, bleeding, difficulty in dissection, difficulty in reconstruction, surgical judgment, technical demand and psychological stress were combined into a complexity of surgery score with a minimum of 7 (very little complexity) and a maximum of 35 (very high complexity).	at the time of surgery
Operative Time	The operative time will be recorded at the time of surgery by the operating surgeon (either after 2 weeks for the Control group and 2-week LCD group or after 6 weeks for the 6-week LCD group)	at the time of surgery

Collaborators and Investigators

• Sponsor: Imperial College London
• Collaborators: Cambridge Weight Plan Limited
• Investigators: Principal Investigator: Prof Gary S Frost, RD PhD, Imperial College London

Publications and helpful links

General Publications

• Bottin JH, Balogun B, Thomas EL, Fitzpatrick JA, Moorthy K, Leeds AR, Bell JD, Frost GS. Changes in body composition induced by pre-operative liquid low-calorie diet in morbid obese patients undergoing Roux-en-Y gastric bypass. Obesity reviews (March 2014), 15 (suppl 2): 129-176. (T5:S24.05). doi: 10.1111/obr.12151

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2011
• Primary Completion (Actual): April 1, 2014
• Study Completion (Actual): April 1, 2014

Study Registration Dates

• First Submitted: May 9, 2014
• First Submitted That Met QC Criteria: May 19, 2014
• First Posted (Estimate): May 22, 2014

Study Record Updates

• Last Update Posted (Actual): March 18, 2021
• Last Update Submitted That Met QC Criteria: February 24, 2021
• Last Verified: February 1, 2021

More Information

Terms related to this study

• Keywords: appetite; diet; morbid obesity; liver fat; gastric bypass; caloric restriction; bariatrics
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity; Obesity, Morbid
• Other Study ID Numbers: CRO1668

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No