Changes in Ingestive Behaviour Following Gastric Bypass

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.

Study Overview

• Status: Completed
• Conditions: Morbid Obesity

• Study Type: Observational
• Enrollment (Actual): 63

Contacts and Locations

Study Locations

• Ireland
  • Letterkenny, Ireland
    • Letterkenny University Hospital
• United Kingdom
  • Co.Londonderry
    • Coleraine, Co.Londonderry, United Kingdom, BT52 1SA
      • Human Intervention Studies Unit, Ulster University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Patients planning to undergo gastric bypass surgery. Control participants with no planned weight loss/gain.

Description

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 Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Gastric bypass patients; Patients planned to undergo Gastric bypass procedure. Patients will be assessed -1 month, 3-, 24-, 48- and 60 months post surgery.
Healthy controls; Healthy controls with no planned weight loss/gain. Control participant assessments will be time-matched with patients.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Food intake	Total energy density (kJ / gram)	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total energy intake	24-hour intake (kJ)	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Relative macronutrient intake	% contribution of macronutrient to energy intake	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Food preferences	Explicit and implicit food preferences measured by the Leeds Food Preference Questionnaire	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Eating occasion size	Grams and kJ over 24 hour period	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Eating speed	g/min and kJ/min over 24 hour period	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Meal frequency	Defined as a continuous period of feeding terminated with a pause >5mins	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Basal Metabolic Rate	Measured by indirect calorimetry	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Percentage body fat	Measured by dual X-ray absorptiometry	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Percentage lean weight	Measured by dual X-ray absorptiometry	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Bone health	Measured by dual X-ray absorptiometry	Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Serum lipid profile		Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Plasma micronutrient status		Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery
Serum C-Reactive Protein		Change from pre-surgery (-1 month) at 3-, 24-, 48- and 60-months post surgery

Collaborators and Investigators

• Sponsor: University of Ulster
• Collaborators: University of Florida; University College Dublin; Letterkenny University Hospital

Publications and helpful links

General Publications

• Livingstone MBE, Redpath T, Naseer F, Boyd A, Martin M, Finlayson G, Miras AD, Bodnar Z, Kerrigan D, Pournaras DJ, le Roux CW, Spector AC, Price RK. Food intake following gastric bypass surgery: patients eat less but do not eat differently. J Nutr. 2022 Jul 23;152(11):2319-32. doi: 10.1093/jn/nxac164. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2016
• Primary Completion (Actual): May 31, 2023
• Study Completion (Actual): May 31, 2023

Study Registration Dates

• First Submitted: April 6, 2017
• First Submitted That Met QC Criteria: April 12, 2017
• First Posted (Actual): April 13, 2017

Study Record Updates

• Last Update Posted (Actual): June 29, 2023
• Last Update Submitted That Met QC Criteria: June 28, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Morbid obesity; Gastric bypass; Food choice; Ingestive behaviour; Food preference
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity; Obesity, Morbid
• Other Study ID Numbers: 16/WS/0056

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No