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Active, Not Recruiting

NCT Number: NCT04788836

How Altered Gut-Brain-Axis Influences Food Choices: Part 2 (BrainFood)

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Food Preferences Behavior Body Weight Feeding Behavior Nutrition Disorders Nutritional and Metabolic Diseases Obesity 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 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.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • 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)

Exclusion criteria

  • Incapacity to give informed consent
  • Primary shopping in other food retailers (e.g. Aldi, Lidl, outside of Switzerland, etc.)

Treatment and study plan

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 shopping

Other

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

Primary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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)).

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

Other outcomes

  1. Correlation between food purchase patterns (i.e. HETI, GPQI, food groups, nutrition facts, Nutri-Score) and self-perceived quality of life

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Quality of life will be assessed using on a scale from 1 (very bad) to 5 (very good)

  2. Changes in energy intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Energy intake in kilocalories (kcal)/day based on Food Frequency Questionnaire

  3. Changes in daily carbohydrate intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  4. Changes in daily sugar intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  5. Changes in daily fibre intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  6. Changes in daily protein intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  7. Changes in daily fat intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  8. Changes in daily saturated fat intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  9. Changes in daily sodium intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in milligram/day based on Food Frequency Questionnaire

  10. Changes in daily vegetable intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  11. Changes in daily wholegrain intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  12. Changes in daily fruit intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  13. Changes in daily dessert intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

  14. Changes in daily meat intake

    Time frame: Pre-treatment until 5 years after start of obesity treatment

    Dietary intake in gram/day based on Food Frequency Questionnaire

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 2: Digital Receipts

Acronym: BrainFood

Important dates

Study start
2021
Primary completion
2026
Study completion
2026
First posted
Mar 9, 2021
Registry last updated
Jun 25, 2025

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.

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