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Changes in Ingestive Behaviour Following Gastric Bypass

Completed
Conditions
Morbid Obesity
Registration Number
NCT03113305
Lead Sponsor
University of Ulster
Brief Summary

The gastric bypass procedure is known to be one of the most successful treatments for morbid obesity and Type 2 diabetes mellitus, and has been shown to decrease appetite, energy intake, body weight and glycemia both in the short and long term. A number of reports hypothesise that these changes may be driven, at least in part, by positive shifts in food preferences following surgery. However, findings are drawn from self-reported dietary intakes which are beset with measurement bias, thus precluding definite conclusions.

The current work aims to directly observe food intake to test the hypothesis that after gastric bypass food intake changes in a manner which leads to beneficial outcomes on body weight when compared to weight stable control participants. Patients (n=32) with a planned gastric bypass procedure will be recruited from Phoenix Health (Ireland and England) and Letterkenny University Hospital (Ireland), alongside control participants (n=32) with no planned weight loss. All subjects will attend the Human Intervention Studies Unit (HISU), Ulster University on five occasions (1-month pre-surgery and 3, 12, 24 and 60 months post-surgery, with controls being time-matched). Study visits will be fully residential involving two overnight stays within the facility during which participants' 24-hour food intake will be covertly measured (7am-11pm Day 2 and breakfast Day 3) and the following procedures undertaken; basal metabolic rate, body composition, bone health, assessment of liking/wanting high fat foods and post-meal gut hormone responses. On each study visit participants will have ad lib access to a range of foods of varying macronutrient composition and which are compatible with their stated food preferences (assessed prior to the start of the study). Changes in all ingestive behaviours will be evaluated over time as compared to the control participants.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
63
Inclusion Criteria
  • >18 years
  • Planned gastric bypass surgery (patients only)
  • No planned weight loss/gain (controls only)
Exclusion Criteria

Patients

  • Significant dysphagia, gastric outlet obstruction or any other factor which prevents consumption of a meal
  • Systemic or gastrointestinal condition which may affect food intake or preference
  • Pregnancy / lactation
  • Significant food allergy or dietary restriction
  • Medication with documented effect on food intake or food preference
  • Any other physical or psychological condition which would affect the outcome of the study as determined by Phoenix Health care team.

Controls

  • Medication with documented effect on food intake / preference or study outcomes
  • Pregnancy / lactation
  • Significant food allergy or dietary restriction
  • Undertaking a weight-loss programme or planning to.

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Food intakeChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Total energy density (kJ / gram)

Secondary Outcome Measures
NameTimeMethod
Food preferencesChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Explicit and implicit food preferences measured by the Leeds Food Preference Questionnaire

Meal frequencyChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Defined as a continuous period of feeding terminated with a pause \>5mins

Percentage body fatChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Measured by dual X-ray absorptiometry

Bone healthChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Measured by dual X-ray absorptiometry

Plasma micronutrient statusChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Total energy intakeChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

24-hour intake (kJ)

Basal Metabolic RateChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Measured by indirect calorimetry

Relative macronutrient intakeChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

% contribution of macronutrient to energy intake

Eating occasion sizeChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Grams and kJ over 24 hour period

Eating speedChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

g/min and kJ/min over 24 hour period

Percentage lean weightChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Measured by dual X-ray absorptiometry

Serum lipid profileChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Serum C-Reactive ProteinChange from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Trial Locations

Locations (2)

Letterkenny University Hospital

🇮🇪

Letterkenny, Ireland

Human Intervention Studies Unit, Ulster University

🇬🇧

Coleraine, Co.Londonderry, United Kingdom

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