Fat Taste Sensory Study

Study Overview
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Brief Summary
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Fat is the most energy dense macronutrient and consuming fat has been positively correlated to obesity. Individuals afflicted with obesity crave fat more frequently, have a higher preference for fatty taste, and consume a higher quantity of fatty foods. People who have undergone Roux-en-Y Gastric Bypass (RYGB) or Sleeve Gastrectomy (SG) weight-loss surgeries dramatically decrease their fat preferences and consumption of fat, at least within the first year after surgery. These surgeries are very effective in helping people lose weight over the first couple of years; however, approximately 30% of those who undergo these surgeries start regaining weight after the second year mark. Why some people are able to keep the weight off long-term but others are unable to is unclear. In addition, it is well-known that fat can modify the flavor of foods and flavor plays a critical role in consumption, as well as in responses that gear up the body to consume the food. These are known as cephalic phase responses and include neural, physiological, and hormonal aspects. The main goals of the study are twofold: 1) To test the immediate effects of RYGB surgery, SG surgery, and laparoscopic gastric banding (LAGB) surgery (a weight loss control group) on fat preferences and sensory perception, and 2) to compare fat preferences and sensory perception between those who are able to achieve sustained weight loss 2-5 years after RYGB or SG surgery and those who either regained weight or did not lose the desired amount.

Detailed Description
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For the first goal, the investigators will assess a longitudinal group of subjects both before RYGB surgery (n=15) SG surgery (n=15), and LAGB surgery (n=15), and then again after they lose  16% of their body weight post-surgery in the fed and the fasted state. the investigators will also study the same variables in a cross-sectional design consisting of two groups: a weight success group (n=30) and a weight failure group (n=30) 2-5 years post RYGB or SG surgery. The weight success group will include subjects who lost ≥40% body weight by 2-5 years post-surgery and the weight failure group will include subjects who lost <25% body weight by 2-5 years post-surgery. In addition, the investigators will also explore the extent to which fat preferences and sensory perception in these subjects are affected by flavor related genes.

Official Title
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Fat Taste Sensory Study

Conditions
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Bariatric Surgery Candidate, Bariatric Surgical Procedure

Intervention / Treatment
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* Procedure: RYGB
* Procedure: SG
* Procedure: LAGB


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women and men, 18-64 years of age, all races Subjects must be scheduled to undergo Roux-en-Y Gastric Bypass surgery (RYGB), Sleeve Gastrectomy surgery (SG), or laparoscopic gastric banding surgery (LAGB) and be available to be tested both pre- and post-surgery or must have undergone RYGB or SG surgery between 2-5 (i.e. at least two years ago and not more than 5) years ago and have a current weight loss that is ≥40% of body weight pre-surgery or <25% of body weight pre-surgery. Exclusion Criteria: Smoking tobacco related cigarettes or having quit smoking less than 6 months ago Pregnant or breastfeeding Are experiencing significant organ dysfunction Take medications that could influence research results Have any psychiatric illness or disorder that could influence compliance or completion of the study History of chronic rhinitis Had a diagnosis of or are taking medicine to treat diabetes Inflammatory intestinal disease Subjects who underwent RYGB or SG between 2-3 years ago and have a current weight loss that is <40% and ≥25% of their body weight pre-surgery. Subjects must find the taste of the food to be sham-fed acceptable (e.g. cream cheese, etc.).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 64 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| RYGB-longitudinal<br>Longitudinal group of subjects studied before and after Roux-n-Y gastric bypass surgery | Procedure: RYGB<br>* RYGB-weight loss surgery<br>|
| SG_longitudinal<br>Longitudinal group of subjects studied before and after sleeve gastrectomy surgery | Procedure: SG<br>* SG- weight loss surgery<br>|
| LAGB_longitudinal<br>Longitudinal group of subjects studied before and after laparoscopic gastric banding surgery | Procedure: LAGB<br>* LAGB- weight loss surgery<br>|
| Weight-loss success<br>Subjects who lost ≥40% body weight by 2-5 years post-surgery | Procedure: RYGB<br>* RYGB-weight loss surgery<br>Procedure: SG<br>* SG- weight loss surgery<br>|
| Weight-loss failure<br>Subjects who lost <25% body weight (or lost more but then regain weight so that now are at <25%) by 2-5 years post-surgery | Procedure: RYGB<br>* RYGB-weight loss surgery<br>Procedure: SG<br>* SG- weight loss surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flavor perception | Changes in perception of flavor intensity in the general label magnitude scale (in mm) | 3-6 months | 
| Flavor preference | Changes in perception of hedonic value in the hedonic version of the general label magnitude scale (in mm) | 3-6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bariatric surgery, gastric bypass surgery, sleeve gastrectomy, laparoscopic gastric banding, food preferences, flavor perception