How Altered Gut-Brain-Axis Influences Food Choices: Part 1
- Conditions
- ObesityFood Preferences
- Interventions
- Other: Functional Brain Imaging and neurobehavioural tasks
- Registration Number
- NCT04813003
- Lead Sponsor
- Lia Bally
- Brief Summary
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.
- Detailed Description
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).
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 50
Not provided
Not provided
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Obesity group (group 1) Functional Brain Imaging and neurobehavioural tasks Pilot phase: 5 adults with class II-III obesity (BMI≥35kg/m2) planned for bariatric surgery will undergo functional imaging and neurobehavioural tasks before bariatric surgery. Refined protocol phase: 20 overweight adults (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). Control group (group 2) Functional Brain Imaging and neurobehavioural tasks Pilot phase: 5 healthy adults with normal body mass (BMI 18.5-24.9kg/m2) matched for age-, sex- and education will serve as a control group and undergo the same experiment. Refined protocol: 20 healthy adults with normal body mass (BMI 18.5-24.9kg/m2) matched for age and sex will serve as a control group and undergo the same experiment.
- Primary Outcome Measures
Name Time Method Representational similarity analysis to assess neural encoding of food attributes 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.
Nutrient factor weights 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 Outcome Measures
Name Time Method 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) Continuously while participants perform the tasks (during 2.5 hours) Activity in the neural areas will be compared between groups
Trial Locations
- Locations (1)
Department of Diabetes, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital
🇨🇭Bern, Switzerland