The SWITCH Dietary and Behavioural Intervention Study

NCT06973408 | Recruiting

• 1 other identifier: SWITCH
• Study Type: interventional
• Target: 300
• Locations: 1 country
• Sites: 1

Brief Summary

The overall objective of this study is to evaluate the effectiveness of an optimized lifestyle intervention based on dietary advice, behavioral support, and provision of key foods compared to dietary advice with behavioral support or dietary advice alone. The intervention aims to improve nutritional status, metabolic risk factors, and planetary sustainability. A total of 300 participants (150 men and 150 women) who meet all inclusion criteria and none of the exclusion criteria will be recruited. The study will be conducted at the Centre for Lifestyle Intervention at Östra Hospital in Gothenburg, led by researchers from Chalmers University of Technology, University of Gothenburg, and Sahlgrenska University Hospital. Participants will be recruited from two different socioeconomic areas in Gothenburg to examine how dietary interventions function in diverse population groups. The study follows a twelve-week randomized, controlled, parallel intervention design. Participants will be randomized into three groups, each with 100 individuals: Optimized lifestyle intervention group - receiving dietary advice, behavioral support, and provision of key foods. Behavioral support intervention group - receiving dietary advice and behavioral support. Control group - receiving dietary advice according to the SWITCH diet. The SWITCH diet, developed within the EU project SWITCH, is designed to align with European dietary guidelines and promote sustainable and healthy eating habits. It emphasizes whole grains, vegetables, fruits, legumes, and sustainable seafood while limiting processed foods, added sugars, and salt. Throughout the study, participants will undergo clinical assessments at baseline, midpoint (week 7), and endpoint (week 13). Key measurements include anthropometric data, blood pressure, blood glucose, blood lipids, and inflammatory markers. Dietary intake and sustainability aspects of food consumption will also be evaluated. Participants in the intervention groups will receive personalized coaching and access to practical resources, such as meal plans, recipes, and visual educational materials. The primary outcome of the study is the difference in cardiometabolic risk factors (e.g., blood lipids, blood pressure, glucose, insulin resistance markers) between the intervention groups. Secondary outcomes include changes in dietary intake, nutritional status markers, inflammatory markers, and sustainability measures (e.g., CO₂ emissions, land use, biodiversity impact). Additionally, exploratory analyses will investigate associations between diet, lifestyle changes, gut microbiota, and metabolic responses. This study aims to generate valuable insights into the effectiveness of different dietary intervention strategies in real-life Nordic conditions. The results will contribute to the development of evidence-based recommendations for sustainable and health-promoting dietary patterns.

Conditions

Dietary Behaviour; Dietary Intakes; Dietary Intervention; Metabolic Diseases; Blood Lipid Profiles; Blood Glucose Metabolism; Diet, Healthy

Keywords

Cardiometabolic health; Lifestyle intervention; Dietary adherence; Sustainable diet; Nordic diet; Metabolic risk factors; Randomized controlled trial; nevironmental impact of diet

Outcome Measures

Primary Outcomes (8)

• LDL cholesterol

  Changes in fasting LDL cholesterol

  After 6 and 12 weeks of intervention

• HDL cholesterol

  Changes in fasting HDL cholesterol

  After 6 and 12 weeks of intervention

• non-HDL cholesterol

  Changes in fasting nonHDL cholesterol

  After 6 and 12 weeks of intervention

• Total cholesterol

  Changes in fasting total cholesterol

  After 6 and 12 weeks of intervention

• Triglyceride

  Changes in fasting triglycerides

  After 6 and 12 weeks of intervention

• Blood pressure

  Change in systolic and/or diastolic blood pressure

  After 6 and 12 weeks of intervention

• Blood glucose

  Changes in fasting blood glucose levels

  After 6 and 12 weeks of intervention

• Insulin

  Changes in c-peptid in fasting samples

  After 6 and 12 weeks of intervention

Secondary Outcomes (4)

• Intake of key food groups and key nutrients

  After 6 and 12 weeks of intervention

• Nutritional status markers

  After 6 and 12 weeks of intervention

• Planetary sustainability measurements

  After 6 and 12 weeks of intervention

• Inflammatory markers

  After 6 and 12 weeks of intervention

Other Outcomes (13)

• Correlation between dietary changes and gut microbiota

  After 6 and 12 weeks of intervention

• Correlation between dietary changes and plasma- and urinary metabolomes

  After 6 and 12 weeks of intervention

• Correlation between lifestyle changes and plasma- and urinary metabolomes

  After 6 and 12 weeks of intervention

Study Arms (3)

Optimized lifestyle intervention group

EXPERIMENTAL

Receiving dietary advice, behavioral support, and provision of key foods.

Behavioral: Behavioral Treatment; Behavioral: Food support; Behavioral: Dietary Advice

Behavioral support intervention group

ACTIVE COMPARATOR

Receiving dietary advice and behavioral support

Behavioral: Behavioral Treatment; Behavioral: Dietary Advice

Control group

OTHER

Receiving dietary advice according to the SWITCH diet.

Behavioral: Dietary Advice

Interventions

Behavioral Treatment BEHAVIORAL

Behavioral support is designed to help participants adhere to the dietary recommendations through personalized coaching and motivational strategies. Participants engage in weekly or bi-weekly coaching sessions, either online or in person, where they receive guidance on overcoming challenges and maintaining dietary changes. The coaching incorporates evidence-based behavior change techniques, such as goal setting, self-monitoring, feedback on performance, problem-solving, and stimulus control. To further support behavior change, participants receive practical tools, including visual aids, educational videos, and structured meal planning resources. The overall goal of behavioral support is to encourage sustainable dietary habits by providing continuous encouragement and individualized strategies.

Also known as: Behavioural support

Behavioral support intervention group; Optimized lifestyle intervention group

Food support BEHAVIORAL

Food support, which is provided exclusively to participants in the Optimized Lifestyle Intervention Group, ensures that they have access to key foods required to meet dietary targets. These foods include whole grains such as whole grain bread, oats, and pasta; vegetables in both fresh and frozen forms; fruits and berries, including apples, pears, and frozen berries; legumes such as lentils, beans, and chickpeas; and seafood, including fatty fish, lean fish, and mussels. To facilitate adherence, participants also receive recipes and meal plans that incorporate these foods. Some fresh food items are made available at supermarkets near participants' residences to improve accessibility and convenience. Food support aims to reduce barriers to dietary change by ensuring that participants have the necessary ingredients to follow the SWITCH diet effectively.

Optimized lifestyle intervention group

Dietary Advice BEHAVIORAL

Dietary advice consists of a simple document outlining the SWITCH diet, which is based on European and Nordic dietary guidelines. Participants receive this information in written form without any additional guidance, counseling, or support. The SWITCH diet emphasizes increased consumption of whole grains, vegetables, fruits, legumes, and seafood while limiting processed foods, added sugars, and excessive salt.

Behavioral support intervention group; Control group; Optimized lifestyle intervention group

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18-70 years
• Body mass index 25-35 kg/m2
• Stable dietary patterns at the entry to the study (no specific dieting the last 4 weeks).
• Willingness to adhere to advised diet pattern and to consume provided key foods.
• Medications stable for the previous 14 days of relevant medicines
• Access to a -18⁰ C freezer to store key foods at home.
• Signed informed consent

You may not qualify if:

• Currently having an infection or other relevant illness.
• Cardiovascular events (myocardial infarction or stroke) during the previous 6 months. To be included, the disease needs to be stable.
• Diagnosis of diabetes (any type).
• Blood Pressure (BP): ≥185/105 mmHg.
• Serum Cholesterol (S-Chol): ≥8 mmol/L.
• Blood Glucose (B-Glucose): fasting value \>7 mmol/L.
• Currently on GLP-1 receptor agonists.
• History of stomach or gastrointestinal diagnoses (inflammatory bowel disease, Crohn's disease, hepatitis, malabsorption, celiac disease etc.).
• IBS- if severe and recent (\<0.5year)?
• Previous colostomy, bowel resection, bariatric surgery or other major gastrointestinal surgery.
• Renal or liver failure (creatinine \<1.7 mg/dl and alanine aminotransferase/ aspartate aminotransferase \> 2 times than normal values (ASAT, ALAT), respectively).
• Anemia or Hemoglobin (Hb): \<100 g/L
• Currently on a specific diet.
• A diet incompatible with protocol diets such as strict vegan/vegetarian.
• Food allergies or intolerances to food items included in the intervention.

Sponsors & Collaborators

• Chalmers University of Technology: lead
• Göteborg University: collaborator
• Vastra Gotaland Region: collaborator

Study Sites (1)

Center for Lifestyle Interventions, Sahlgrenska University Hospital, Östra

Gothenburg, Sweden

RECRUITING

MeSH Terms

Conditions

Metabolic Diseases

Interventions

Behavior Therapy; Nutrition Assessment

Condition Hierarchy (Ancestors)

Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Psychotherapy; Behavioral Disciplines and Activities; Data Collection; Epidemiologic Methods; Investigative Techniques; Health Care Evaluation Mechanisms; Quality of Health Care; Health Care Quality, Access, and Evaluation; Epidemiologic Measurements; Public Health; Environment and Public Health

Central Study Contacts

Rikard Landberg, Professor

CONTACT

+46723509386; rikard.landberg@chalmers.se

Malin Barman, Docent

CONTACT

+46317722393; malin.barman@chalmers.se

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: March 20, 2025
• First Posted: May 15, 2025
• Study Start: March 3, 2025
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): November 30, 2026
• Last Updated: May 15, 2025

Record last verified: 2025-05

Locations

SE (1)