Food PreferencesBrainFoodNCT04788836
How Altered Gut-Brain-Axis Influences Food Choices: Part 2 (BrainFood)
An observational study of Food Preferences and Obesity, run by Lia Bally at 1 site in Switzerland.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Food Preferences, Obesity
- What is being tested?
- Questionnaire (Survey and Food Frequency Questionnaire (FFQ)) and Collection of digital receipts from grocery shopping
- How many people
- 61 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Nov 2021to 31 Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: A minimum of 60 (up to a maximum of 150) overweight/obese adults planned for or who started surgical or non-surgical obesity treatment within the past 6 months will be recruited for this study. Participants will be recruited by referral from our outpatient endocrine clinic and collaborating Centres of Excellence for Metabolic Surgery.
Who may be able to join
- Female and male subjects aged 18 years or older
- Proficient in German (including written)
- BMI≥30kg/m2 or BMI≥28kg/m2 with adiposity-related comorbidities (prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia)
- Referred for obesity treatment or who started obesity treatment within 6 months (surgical or non-surgical)
- Primary grocery shopping at the Swiss biggest grocery retailers (Coop, Migros), and regularly using a loyalty card (Cumulus and/or Supercard)
Who cannot join
- Incapacity to give informed consent
- Primary shopping in other food retailers (e.g. Aldi, Lidl, outside of Switzerland, etc.)
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Department of Diabetes, Endocrinology, Clinical Nutrition and Metabolism, Inselspital, Bern University Hospital
Bern, 3010
About this study
Official title: How Altered Gut-Brain-Axis Influences Food Choices. (BrainFood) Part 2: Digital Receipts
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. GLP-1 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 and food purchase behaviour remain unknown.
In Part 2 of the BrainFood-project, the investigators propose a novel approach using digital receipts from loyalty card to unravel the effect of obesity treatments (surgical and non-surgical) on eating and food purchase behaviour in daily life.
Read the detailed description
The overall aim of this project is to elucidate the changes in food behaviour among obese adults undergoing obesity treatments.
The main objective is to observe the effect of obesity treatments on food purchase behaviour using digital receipts from grocery shopping. The investigators hypothesize that bariatric surgery leads to changes in food purchase behaviour in obese adults.
The further objective is to compare food purchase behaviour between obese adults against values of an existing reference population, and to assess whether these differences tend to be reduced after the start of the treatment among obese participants.
- Conditions
- Food Preferences, Obesity
- Being tested
- Questionnaire (Survey and Food Frequency Questionnaire (FFQ)), Collection of digital receipts from grocery shopping
- Keywords
- Bariatric surgery, Food preferences, Food behaviour, Digital receipts, Grocery Shopping, Obesity treatment, GLP-1 receptor agonist
- Medical subject headings
- Food Preferences, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Questionnaire (Survey and Food Frequency Questionnaire (FFQ))Other
Each participant will be asked to fill a web-based questionnaire that captures sociodemographic, lifestyle, physical and mental health information (Survey) and dietary intake patterns (FFQ). This will be done pre-treatment (only for those included pre-treatment), 6 months after the start of obesity treatment, 1 year after the start of the treatment and then yearly until 5 year after the start of the treatment.
Collection of digital receipts from grocery shoppingOther
Participants will create their BitsaboutMe-account (GDPR-compliant data sharing platform from Bern, Switzerland) with the help of study team members. Data from digital receipts will be obtained from Migros Cumulus and Coop Supercard via their BitsaboutMe-account. The data collection allow retrospective digital receipts collection for up to 2 years and automatically continuous collection during study duration.
GDPR: General Data Protection Regulation
| Study group | Role | What they receive |
|---|---|---|
| Obesity treatment Group | 60 (minimum) to 150 (maximum) overweight/obese adults referred for or who started obesity (surgical or non-surgical) treatment within 6 months Receives: Other: Questionnaire (Survey and Food Frequency Questionnaire (FFQ)); Other: Collection of digital receipts from grocery shopping | |
| Control Group | Comparison of food purchase behaviour with control subjects will be performed using an already existing cohort from a previous study. This does not required recruiting control subjects. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in food purchase behaviour on the basis of the Healthy Trolley Index (HETI)
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the HETI, an objective and validated, nutrient-based, healthy shopping scoring system.
Measured: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour on the basis of the Grocery Purchase Quality Index (GPQI)
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the GPQI, an objective and validated, nutrient-based, healthy shopping scoring system.
Measured: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour on the basis of food groups
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of food groups like vegetables, wholegrain, fruits, sweets and meats.
Measured: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour on the basis of nutrition facts
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of nutrition facts like energy (kcal), carbohydrates, sugars, added sugars, protein, fat, saturated fat, dietary fibre and salt.
Measured: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour on the basis of the Nutri-Score
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the Nutri-Score, representing the nutritional quality of products. The Nutri-Score is based on a discrete continuous scale from -15 (most healthy) to 40 (least healthy). The score is then transcribed into five colour categories (A-E, ranging from bright green (most healthy) to red (least healthy)).
Measured: Pre-treatment until 5 years after start of obesity treatment
Food purchase behaviour on the basis of the Healthy Trolley Index (HETI)
HETI will be compared between obesity treatment group and control group
Measured: Pre-treatment until 5 years after start of obesity treatment
Food purchase behaviour on the basis of the Grocery Purchase Quality Index (GPQI)
GPQI will be compared between obesity treatment group and control group
Measured: Pre-treatment until 5 years after start of obesity treatment
Food purchase behaviour on the basis of food groups
Food groups will be compared between obesity treatment group and control group
Measured: Pre-treatment until 5 years after start of obesity treatment
Food purchase behaviour on the basis of nutrition facts
Nutrition facts will be compared between obesity treatment group and control group
Measured: Pre-treatment until 5 years after start of obesity treatment
Food purchase behaviour on the basis of the Nutri-Score
Nutri-Score will be compared between obesity treatment group and control group
Measured: Pre-treatment until 5 years after start of obesity treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Mar 2021
- Study start1 Nov 2021
- Primary completion31 Dec 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Food PreferencesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 61 participants (actual)
Sponsor and investigators
- Lead sponsor
- Lia Bally
- Sponsor type
- University, hospital or other
- Collaborators
- ETH Zurich
- Responsible party
- Sponsor-investigator, Lia Bally, Insel Gruppe AG, University Hospital Bern
- Investigators
- Lia Bally, MD, PhD, Principal investigator, University Hospital Bern & University of Bern
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04788836
- Sponsor's protocol ID
- BrainFood Part 2
- Acronym
- BrainFood
- Status last verified
- Aug 2026
- First submitted
- 18 Jan 2021
- Last updated
- 5 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- How Altered Gut-Brain-Axis Influences Food Choices. (BrainFood) Part 2: Digital Receipts
- ClinicalTrials.gov ID
- NCT04788836
- Acronym / sponsor ID
- BrainFood / BrainFood Part 2
- Conditions
- Food Preferences, Obesity
- Keywords
- Bariatric surgery, Food preferences, Food behaviour, Digital receipts, Grocery Shopping, Obesity treatment, GLP-1 receptor agonist
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 61 participants (actual)
- Lead sponsor
- Lia BallyUniversity, hospital or other
- Collaborators
- ETH Zurich
- Study start
- 1 Nov 2021 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 9 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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. GLP-1 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 and food purchase behaviour remain unknown.
In Part 2 of the BrainFood-project, the investigators propose a novel approach using digital receipts from loyalty card to unravel the effect of obesity treatments (surgical and non-surgical) on eating and food purchase behaviour in daily life.
Detailed description
The overall aim of this project is to elucidate the changes in food behaviour among obese adults undergoing obesity treatments.
The main objective is to observe the effect of obesity treatments on food purchase behaviour using digital receipts from grocery shopping. The investigators hypothesize that bariatric surgery leads to changes in food purchase behaviour in obese adults.
The further objective is to compare food purchase behaviour between obese adults against values of an existing reference population, and to assess whether these differences tend to be reduced after the start of the treatment among obese participants.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Obesity treatment Group | – | Other: Questionnaire (Survey and Food Frequency Questionnaire (FFQ)), Other: Collection of digital receipts from grocery shopping60 (minimum) to 150 (maximum) overweight/obese adults referred for or who started obesity (surgical or non-surgical) treatment within 6 months |
| Control Group | – | –Comparison of food purchase behaviour with control subjects will be performed using an already existing cohort from a previous study. This does not required recruiting control subjects. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- A minimum of 60 (up to a maximum of 150) overweight/obese adults planned for or who started surgical or non-surgical obesity treatment within the past 6 months will be recruited for this study. Participants will be recruited by referral from our outpatient endocrine clinic and collaborating Centres of Excellence for Metabolic Surgery.
Key inclusion criteria (5 listed)
- Female and male subjects aged 18 years or older
- Proficient in German (including written)
- BMI≥30kg/m2 or BMI≥28kg/m2 with adiposity-related comorbidities (prediabetes, type 2 diabetes mellitus, hypertension, dyslipidemia)
- Referred for obesity treatment or who started obesity treatment within 6 months (surgical or non-surgical)
- Primary grocery shopping at the Swiss biggest grocery retailers (Coop, Migros), and regularly using a loyalty card (Cumulus and/or Supercard)
Key exclusion criteria (2 listed)
- Incapacity to give informed consent
- Primary shopping in other food retailers (e.g. Aldi, Lidl, outside of Switzerland, etc.)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Questionnaire (Survey and Food Frequency Questionnaire (FFQ))Each participant will be asked to fill a web-based questionnaire that captures sociodemographic, lifestyle, physical and mental health information (Survey) and dietary intake patterns (FFQ). This will be done pre-treatment (only for those included pre-treatment), 6 months after the start of obesity treatment, 1 year after the start of the treatment and then yearly until 5 year after the start of the treatment. | Other | Obesity treatment Group |
| Collection of digital receipts from grocery shoppingParticipants will create their BitsaboutMe-account (GDPR-compliant data sharing platform from Bern, Switzerland) with the help of study team members. Data from digital receipts will be obtained from Migros Cumulus and Coop Supercard via their BitsaboutMe-account. The data collection allow retrospective digital receipts collection for up to 2 years and automatically continuous collection during study duration. GDPR: General Data Protection Regulation | Other | Obesity treatment Group |
Primary outcome
Changes in food purchase behaviour on the basis of the Healthy Trolley Index (HETI)
Time frame: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the HETI, an objective and validated, nutrient-based, healthy shopping scoring system.
Changes in food purchase behaviour on the basis of the Grocery Purchase Quality Index (GPQI)
Time frame: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the GPQI, an objective and validated, nutrient-based, healthy shopping scoring system.
Changes in food purchase behaviour on the basis of food groups
Time frame: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of food groups like vegetables, wholegrain, fruits, sweets and meats.
Changes in food purchase behaviour on the basis of nutrition facts
Time frame: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of nutrition facts like energy (kcal), carbohydrates, sugars, added sugars, protein, fat, saturated fat, dietary fibre and salt.
Changes in food purchase behaviour on the basis of the Nutri-Score
Time frame: Pre-treatment until 5 years after start of obesity treatment
Changes in food purchase behaviour pre-treatment will be compared to post-treatment on the basis of the Nutri-Score, representing the nutritional quality of products. The Nutri-Score is based on a discrete continuous scale from -15 (most healthy) to 40 (least healthy). The score is then transcribed into five colour categories (A-E, ranging from bright green (most healthy) to red (least healthy)).
Food purchase behaviour on the basis of the Healthy Trolley Index (HETI)
Time frame: Pre-treatment until 5 years after start of obesity treatment
HETI will be compared between obesity treatment group and control group
Food purchase behaviour on the basis of the Grocery Purchase Quality Index (GPQI)
Time frame: Pre-treatment until 5 years after start of obesity treatment
GPQI will be compared between obesity treatment group and control group
Food purchase behaviour on the basis of food groups
Time frame: Pre-treatment until 5 years after start of obesity treatment
Food groups will be compared between obesity treatment group and control group
Food purchase behaviour on the basis of nutrition facts
Time frame: Pre-treatment until 5 years after start of obesity treatment
Nutrition facts will be compared between obesity treatment group and control group
Food purchase behaviour on the basis of the Nutri-Score
Time frame: Pre-treatment until 5 years after start of obesity treatment
Nutri-Score will be compared between obesity treatment group and control group
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lia Bally, MD, PhD principal investigator
University Hospital Bern & University of Bern
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Food Preferences and Obesity, run by Lia Bally at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in food purchase behaviour on the basis of the Healthy Trolley Index (HETI) (time frame: Pre-treatment until 5 years after start of obesity treatment). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026.