Clinical trial NCT01531738: Investigation of the Effects of Bariatric Surgery on Taste Reward in Humans
Official title: Investigation of the Effects of Bariatric Surgery on Taste Reward in Humans
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obesity
Keywords: Taste
bariatric surgery
food preferences
reward
progressive ratio task
Lead sponsor: Imperial College London
Sponsor class: OTHER
Collaborators: name: Medical Research Council
First posted: 2012-02-13
Enrollment: 22
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with obesity attending a specialist obesity clinic and normal weight controls who are staff at Imperial College London

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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Breakpoints as Assessed by Change in the Number of Mouse Clicks in the Last Completed Ratio
timeFrame: 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
Secondary outcomes:
measure: Hunger
timeFrame: 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
measure: Body Mass Index
timeFrame: 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
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: Imperial Weight Centre, Imperial College London
Study officials:
affiliation: Imperial College London
name: Carel W le Roux, MRCP PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Miras AD, Jackson RN, Jackson SN, Goldstone AP, Olbers T, Hackenberg T, Spector AC, le Roux CW. Gastric bypass surgery for obesity decreases the reward value of a sweet-fat stimulus as assessed in a progressive ratio task. Am J Clin Nutr. 2012 Sep;96(3):467-73. doi: 10.3945/ajcn.112.036921. Epub 2012 Jul 25.