Skip to main content
OpenTrials
Completed

NCT Number: NCT04813003

How Altered Gut-Brain-Axis Influences Food Choices: Part 1

Obesity is currently one of the most substantial health burdens. Due to the production of marked and sustained weight loss, bariatric surgery is an increasingly used therapeutic modality to combat obesity and its comorbidities. Surgical rearrangement of the gastrointestinal tract remarkably alters metabolism and hormones acting on neurological and hypothalamic signalling involved in food decision-making and eating behaviour. In this context, many patients who underwent bariatric surgery self-report changes in appetite, satiety and food preferences. Furthermore, new gut hormone-based (e.g. GLP1-receptor agonist or GLP-1-RA) pharmacotherapies which mimic the effect of bariatric surgery show impressive efficacy on weight reduction by modulation of food behaviour. However, the mechanisms of such functional changes, and how they relate to food decision-making remain unknown.

In this project, the investigators propose a novel approach to unravel the effect of obesity treatments (surgical and non-surgical) on the neural coding of nutritional attributes and its impact on dietary choices using a combination of brain imaging, computational modelling of food behaviour and assessment of eating and food purchase behaviour in daily life.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Obesity Behavior Body Weight Feeding Behavior Food Preferences Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Department of Diabetes, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital

Bern, 3010, Switzerland

About this study

The overall aim of this project is to elucidate the neurobehavioural underpinnings of food behaviour among obese adults and how food behavior is altered by different obesity treatments.To this end, the study consists of an experimental setting combining neurobehavioural tasks, computational modelling and functional brain imaging.

The main objective of Part 1 of the BrainFood-project is to elucidate if neural coding and food behaviour differ between obese adults and lean adults. The investigators hypothesize that subjective neural processes of nutritional food attributes differ between the obese and control participants, showing an unhealthier pattern among obese participants.

To this aim, the outcomes will be compared between groups (surgery group and control group).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

(all participants):

  • Female and male subjects aged 18 years or older
  • Proficient German language skills (including written)

Inclusion criteria

for Group 1 (pilot protocol):

  • Class II-III obesity (BMI≥35kg/m2)
  • Planned for bariatric surgery (Roux-en-Y gastric bypass)

Inclusion criteria

for Group 1 (refined protocol):

  • BMI≥30kg/m2 or BMI≥28kg/m2 with adiposity-related comorbidities (prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia)
  • Referred for obesity treatment (surgical or non-surgical)

Inclusion criteria

for Group 2 (pilot and refined protocols):

  • Normal body weight (BMI 18.5-24.9kg/m2)
  • Absence of evidence of any active or chronic disease as judged by the Clinical Investigator

Exclusion criteria

  • Incapacity to give informed consent
  • Previous or current neurological or severe psychiatric illness
  • Current or planned pregnancy or breastfeeding
  • Claustrophobia
  • MRI-contraindications (pacemaker/defibrillator, neurostimulator, drug pump, cochlear implant, heart valve/vascular clips, shunt valve)
  • Pilot protocol only: Diabetes according to WHO (World Health Organization ) definition (Fasting plasma glucose ≥7.0mmol/l, random plasma glucose ≥11.1mmol/l, HbA1c ≥6.5%)

Treatment and study plan

Functional Brain Imaging and neurobehavioural tasks

Other

Combination of 3 neurobehavioural tasks:

Task 1 consists in subjective value rating of 64 food items. Participants are asked to rate how much they would want to eat the presented food item while fMRI (functional magnetic resonance imaging ) scanning is performed.

Task 2 consists in rating of subjective nutrient factor of the same 64 food items. Participants will answer the following four categorical questions in randomized order for each item: low or high in added sugar/protein/fat and healthy or unhealthy.

Task 3 consists of a decision-making task. Participants will be presented with two food items (out of the 64 food items), and asked to choose which of the two items they prefer to consume at the end of the experiment.

Primary outcomes

  1. Representational similarity analysis to assess neural encoding of food attributes

    Time frame: Continuously while participants perform the tasks (during 2.5 hours)

    Representational similarity analysis is used to analyse the correlation between a voxel-wise representational dissimilarity matrix and a behavioural representational dissimilarity matrix. The correlation of the activity of each voxel for each pair of food items is used to define the voxel-wise representational dissimilarity matrix. Similarly, the correlation of the subjective ratings for each pair of food items is used to define the behavioural representational dissimilarity matrix. The correlation between the voxel-wise representational dissimilarity matrix and the behavioural representational dissimilarity matrix is then assessed to determine if the voxels are encoding the food attributes.

  2. Nutrient factor weights

    Time frame: Continuously while participants perform the tasks (during 2.5 hours)

    The nutrient factor weights are estimated using a linear regression with the subjective value ratings as dependent variable and nutrient factors ratings as independent variables and using a logistic regression with the choice as a dependent variable and the nutrient factor ratings as independent variables.

Secondary outcomes

  1. Differences in activity in neural areas involved in self-control and valuation (Dorsolateral prefrontal cortex (dlPFC), ventromedial prefrontal cortex (vmPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), insula, hippocampus)

    Time frame: Continuously while participants perform the tasks (during 2.5 hours)

    Activity in the neural areas will be compared between groups

Sponsors and collaborators

Lead sponsor

Lia Bally

Other

Collaborators

  • ETH Zurich

Registry information

Official study title

How Altered Gut-Brain-Axis Influences Food Choices. (BrainFood) Part 1: Brain Imaging and Computational Modelling

Acronym: BrainFood

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Mar 24, 2021
Registry last updated
Sep 23, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.