Roux-en-Y Gastric Bypass and Weight Regain
Condition: Obesity
Study type: Observational

Summary: 
      This study compares eating behaviors, meal size, and the size of the gastric pouch and
      connection between the gastric pouch and small intestine in patients who had gastric bypass
      surgery two or more years ago and regained weight compared with patients who had gastric
      bypass surgery two or more years ago and maintained their weight loss.
    

Detailed description: 
      Obesity affects a third of adults in the United States. The most effective treatment for
      weight loss is bariatric surgery, and the most common surgery performed in the US is
      Roux-en-Y Gastric Bypass (RYGB). However, a significant number of patients regain weight that
      was lost after surgery. The mechanisms for weight regain are likely multifactorial, but not
      well understood. Disordered eating behaviors and dilated gastrojejunostomies (GJ), which
      presumably allows a patient to consume larger portion sizes during a meal, correlate with
      weight regain. Moreover, some data suggest that changes to the gut anatomy may drive eating
      behaviors and food preferences. However, no studies have simultaneously evaluated functional
      gastric volume (the volume of solid or liquid food that can be consumed to a level of
      comfortable fullness in one sitting), anatomical gastric pouch size and GJ diameter, and
      eating behaviors in patients who maintained their post RYGB weight compared with patients who
      have regained weight from their maximum weight loss after RYGB to determine the relationship
      among post RYGB eating behavior, functional and anatomical gastric pouch size, GJ diameter
      and weight change. Accordingly, the objectives of this proposal are to compare 1) eating
      behaviors 2) functional gastric volume and 3) anatomical dimensions of the gastric pouch and
      GJ in patients who are >2 years post RYGB and have regained >20% of their maximum lost weight
      and those who are >2 years post RYGB and have maintained at least 90% weight loss since
      surgery. The following specific aims will be evaluated:

      Aim 1. Evaluate whether differences in eating behaviors exist between subjects who have
      maintained weight loss after RYGB or regained >20% of their maximum lost weight. The
      investigators hypothesize that subjects who have regained weight after RYGB will have higher
      scores on binge eating behaviors and an increased craving for sweets compared with patients
      who have maintained weight loss after RYGB. Eating behaviors will be determined by performing
      the Yale Food Addiction Scale (YFAS), Eating Disorder Examination (EDE), The Food Craving
      Inventory (FCI), and the National Cancer Institute (NCI) ASA24.

      Aim 2. Evaluate whether differences exist in functional gastric volume between subjects who
      have maintained weight loss after RYGB or regained >20% of their maximum lost weight. The
      investigators hypothesize that patients who have regained weight after RYGB will have an
      increased functional gastric volume to both solids and liquids compared to subjects who have
      maintained weight loss after RYGB. Functional gastric volume will be measured during both a
      solid and liquid meal test.

      Aim 3. Evaluate whether differences exist in gastric pouch and GJ sizes between subjects who
      have maintained weight loss after RYGB or regained >20% of their maximum lost weight. The
      investigators hypothesize that patients who have regained weight after RYGB will have
      increased gastric pouch size and GJ diameter compared with patients who have maintained their
      weight loss after RYGB. Anatomical dimensions of the gastric pouch and GJ will be determined
      by using an articulated measuring tool during upper GI tract endoscopy.
    

Intervention name(s): Eating Behavior Evaluation; Measurement of Functional gastric volume; Measurement of gastric pouch and GJ size
Intervention type(s): Behavioral; Other; Other
Intervention description(s): Scores will be measured on binge eating behaviors and an increased craving for sweets.; The functional gastric volume is the amount of food or liquid that can be consumed to a feeling of comfortably full in one meal.; Anatomical dimensions of the gastric pouch and GJ will be determined by using an articulated measuring tool during upper GI tract endoscopy.
Other intervention name(s): Yale Food Addiction Scale (YFAS); Eating Disorder Examination (EDE); The Food Craving Inventory (FCI); National Cancer Institute (NCI) ASA24
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        The study population will consist of 20 patients who had laparoscopic RYGB surgery >2 years
        before screening and have regained >20% weight from their maximum weight lost after surgery
        and 20 patients who had laparoscopic RYGB surgery >2 years before screening and have
        maintained at least 90% weight loss from the maximum weight loss after surgery. These
        patients will be identified from the bariatric surgical population at Washington University
        School of Medicine.
      
Keywords: Roux-en-Y Gastric Bypass Surgery; Weight Regain