Investigation of the Effects of Bariatric Surgery on Taste Reward in Humans

• Sponsor: Imperial College London (Other)
• Overall Status: Completed
• CT.gov ID: NCT01531738
• Collaborator: Medical Research Council (Other)
• Enrollment: 22
• Location: 1
• Duration (Months): 18
• Patients Per Site Per Month: 1.2

Study Details

Study Description

Brief Summary

The investigators hypothesize that some of these changes in the reduced appetite after surgery may be due to alterations in taste. The aim is to compare obese patients before and after bariatric surgery (gastric bypass and banding) to define the reward value of sweet, fatty and vegetable/fruit taste in obese individuals, and how this changes after surgery.

Condition or Disease	Intervention/Treatment	Phase
Obesity

Detailed Description

Severe obesity is associated with excessive food eating and appetite. Bariatric surgery (also known as 'obesity surgery' or 'weight loss surgery') is a well known treatment for severely obese individuals. The way in which these operations achieve weight loss is not fully understood. The investigators hypothesize that some of these changes in the reduced appetite after surgery may be due to alterations in taste. The aim is to compare obese patients before and after bariatric surgery (gastric bypass and banding) to define the reward value of sweet, fatty and vegetable/fruit taste in obese individuals, and how this changes after surgery.

Study Design

• Study Type: Observational
• Actual Enrollment: 22 participants
• Observational Model: Case-Control
• Time Perspective: Prospective
• Official Title: Investigation of the Effects of Bariatric Surgery on Taste Reward in Humans
• Study Start Date: Jul 1, 2010
• Actual Primary Completion Date: Jan 1, 2012
• Actual Study Completion Date: Jan 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Control Normal weight healthy volunteers
Bariatric Surgery obese patients due to undergo gastric bypass or gastric banding

Outcome Measures

Primary Outcome Measures

1. Breakpoints as Assessed by Change in the Number of Mouse Clicks in the Last Completed Ratio [2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group]

   Patients were placed in front of a computer screen and a plate of 20 chocolate candies. The following prompt appeared on the screen: "You can earn food by clicking on the mouse button. Click as much or as little as you like. When you no longer want to continue, press the spacebar to stop the session."Upon completion of each ratio a message box appeared on the screen: "You have earned food. Enjoy your reward and after you have swallowed it completely you may click on OK to continue with the programme."After ingesting the reward, the patients pressed the OK button in the message box only if they wished to progress to the next ratio to obtain another chocolate candy. The starting ratio was 10 clicks with a geometric increment of 2 (i.e., 10, 20, 40, 80, and so on). When the effort of pressing the mouse button was greater than the rewarding value of the chocolate candy, patients pressed on the space bar to terminate the session. This indicated that the breakpoint was reached.

Secondary Outcome Measures

1. Hunger [2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group]

   Visual Analogue Scale ratings of hunger. The scale is 100mm line with two anchors at each end. Scores are recorded by making a handwritten mark that represents a continuum between "not hungry at all" and "Extremely hungry." The score of 0 represents least hunger. The score of 100 represents extreme hunger. change in hunger levels quantified by a 100mm visual analogue scale

2. Body Mass Index [2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group]

   change in BMI will be quantified based on the participants weight in kilograms and height in meters

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 65 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

• BMI of 18-25 for normal weight volunteers

• BMI of >30 for obese patients

Exclusion Criteria:

• Pregnancy

• breast feeding

• substance abuse

• consumption of more than 3 alcoholic units per day

• severe psychiatric illness

• lack of understanding of test instructions

• diabetes mellitus

• chronic medical conditions making a general anaesthetic unsafe

• allergy to stimulus ingredients

• active smoking

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Imperial Weight Centre, Imperial College London	London		United Kingdom	W6 8RF

Sponsors and Collaborators

• Imperial College London
• Medical Research Council

Investigators

• Principal Investigator: Carel W le Roux, MRCP PhD, Imperial College London

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Carel Le Roux, Principal Investigator, Imperial College London
• ClinicalTrials.gov Identifier: NCT01531738
• Other Study ID Numbers: PRT
• First Posted: Feb 13, 2012
• Last Update Posted: Nov 16, 2020
• Last Verified: Oct 1, 2020

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Keywords provided by Carel Le Roux, Principal Investigator, Imperial College London: Taste; bariatric surgery; food preferences; reward; progressive ratio task

Study Results

Participant Flow

Arm/Group Title	Control	Bariatric Surgery
Arm/Group Description	Normal weight healthy volunteers	obese patients due to undergo gastric bypass or gastric banding
Period Title: Overall Study
STARTED	11	11
COMPLETED	11	11
NOT COMPLETED	0	0

Baseline Characteristics

Arm/Group Title	Control	Bariatric Surgery	Total
Arm/Group Description	Normal weight healthy volunteers	obese patients due to undergo gastric bypass or gastric banding	Total of all reporting groups
Overall Participants	11	11	22
Age, Customized (years) [Mean (Standard Deviation) ]
Age	39 (5)	49 (3)	44 (4)
Sex: Female, Male (Count of Participants)
Female	7 63.6%	7 63.6%	14 63.6%
Male	4 36.4%	4 36.4%	8 36.4%
Ethnicity (NIH/OMB) (Count of Participants)
Hispanic or Latino	0 0%	0 0%	0 0%
Not Hispanic or Latino	11 100%	11 100%	22 100%
Unknown or Not Reported	0 0%	0 0%	0 0%
BMI ("kg/m^2) (kg/m^2) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [kg/m^2]	23 (1)	48 (2)	35.5 (1.5)

Outcome Measures

1. Primary Outcome

Title	Breakpoints as Assessed by Change in the Number of Mouse Clicks in the Last Completed Ratio
Description	Patients were placed in front of a computer screen and a plate of 20 chocolate candies. The following prompt appeared on the screen: "You can earn food by clicking on the mouse button. Click as much or as little as you like. When you no longer want to continue, press the spacebar to stop the session."Upon completion of each ratio a message box appeared on the screen: "You have earned food. Enjoy your reward and after you have swallowed it completely you may click on OK to continue with the programme."After ingesting the reward, the patients pressed the OK button in the message box only if they wished to progress to the next ratio to obtain another chocolate candy. The starting ratio was 10 clicks with a geometric increment of 2 (i.e., 10, 20, 40, 80, and so on). When the effort of pressing the mouse button was greater than the rewarding value of the chocolate candy, patients pressed on the space bar to terminate the session. This indicated that the breakpoint was reached.
Time Frame	2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Control	Bariatric Surgery
Arm/Group Description	Normal weight healthy volunteers	obese patients due to undergo gastric bypass or gastric banding
Measure Participants	11	11
Mean (Standard Deviation) [Clicks]	0 (40)	320 (30)

2. Secondary Outcome

Title	Hunger
Description	Visual Analogue Scale ratings of hunger. The scale is 100mm line with two anchors at each end. Scores are recorded by making a handwritten mark that represents a continuum between "not hungry at all" and "Extremely hungry." The score of 0 represents least hunger. The score of 100 represents extreme hunger. change in hunger levels quantified by a 100mm visual analogue scale
Time Frame	2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Control	Bariatric Surgery
Arm/Group Description	Normal weight healthy volunteers	obese patients due to undergo gastric bypass or gastric banding
Measure Participants	11	11
Mean (Standard Deviation) [mm]	20 (30)	-60 (30)

3. Secondary Outcome

Title	Body Mass Index
Description	change in BMI will be quantified based on the participants weight in kilograms and height in meters
Time Frame	2 weeks pre and 8-12 weeks post operatively for surgical patients or on two occasions 10-14 weeks apart for normal weight control group

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Control	Bariatric Surgery
Arm/Group Description	Normal weight healthy volunteers	obese patients due to undergo gastric bypass or gastric banding
Measure Participants	11	11
Mean (Standard Deviation) [kg/m^2]	-0.2 (1.2)	-6.2 (1.6)

Adverse Events

Time Frame	1 year
Arm/Group Title	Control		Bariatric Surgery
Arm/Group Description	Normal weight healthy volunteers		obese patients due to undergo gastric bypass or gastric banding
All Cause Mortality
	Control		Bariatric Surgery
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/11 (0%)		0/11 (0%)
Serious Adverse Events
	Control		Bariatric Surgery
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/11 (0%)		0/11 (0%)
Other (Not Including Serious) Adverse Events
	Control		Bariatric Surgery
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/11 (0%)		0/11 (0%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.