Overview

The overall objective of this multi-center study is to use metabolic response data from different dietary challenges to develop personalized dietary advice. Effectiveness of this personalized dietary advice compared to a general healthy diet based on national dietary guidelines on markers of cardio-metabolic health will be tested.

A total of 120 men and women who meet all inclusion criteria and none of the exclusion criteria will be invited to participate. The study will be conducted at three sites: Chalmers University of Technology (Sweden), University of Wageningen (Netherlands), and University of Oslo (Norway), with 40 participants per site.The study is conducted in two parts. The first part, the characterization phase, is a three-way randomized, controlled cross-over design, featuring one-day meal tests with isocaloric meals containing different carbohydrate, fat and protein quantity as well as quality. Based on the metabolic response to the meal tests a personalized diet will be constructed. In the second part, the main intervention, effectiveness of this personalized dietary advice compared to a general healthy diet will be tested in a six week parallel group intervention study.

Eligibility

Inclusion Criteria:

• Men and women
• Age 40 to 70 years
• Body mass index (BMI) 27-35 kg/m2
• Signed informed consent

Exclusion Criteria:

• History of diagnosed cardiovascular disease (e.g. stroke, heart disease)
• Diagnosed type 1 or type 2 diabetes
• Finger prick glucose test at screening indicating diabetes (fasting >6.9 mmol/L; non-fasting >11.0 mmol/L)
• Antibiotic use in the last 3 months
• Taking medication that can interfere with the planned outcome measures, as judged by the study physician (e.g. peroxisome proliferator-activated receptor-α [PPAR-α] or PPAR-γ agonists [fibrates], sulfonylureas, biguanides, α-glucosidase inhibitors, thiazolidinediones, repaglinide, nateglinide and insulin, chronic use of NSAIDs). Statins and hypertension medication are allowed if the medication regimen has been stable for the last three months
• Stomach and gastrointestinal conditions (e.g. Morbus Chron, Ulcerative colitis, irritable bowel syndrome, malabsorption, colostomy, bowel resection, gastric bypass surgery etc.)
• History of major gastrointestinal surgery
• Anaemia: Hb concentrations < 8.5 mmol/L for men and < 7.5 mmol/L for women
• Recent blood donation (within 2 months prior to the screening)
• Recent participation in another intervention study (within 2 months prior to the screening)
• Allergy or intolerance to medical skin adhesives
• Chronic or acute inflammatory conditions (e.g., rheumatoid arthritis, psoriatic arthritis)
• Autoimmune disorders
• Thyroid disorders
• Significant renal or liver dysfunction or chronic kidney or liver disease
• Known food allergies/intolerances to intervention foods or food products used in the study
• Following specific dietary regimen that could impact results or not suitable for the study design (e.g. vegetarian, vegan)
• Habitual tobacco consumption (e.g. smoking, use of snus, vaping)
• Alcohol intake ≥ 14 alcoholic beverages/week for women and ≥ 21 alcoholic beverages/week for men
• Current or planned pregnancy or lactating
• Other serious medical conditions that could interfere with participation or study outcomes
• Unable to sufficiently understand written and spoken national language (where the study centre is located) to provide written consent and understand information and instructions from the study personnel.
• Deemed unsuitable for participation in the trial, for any reason, as judged by the research physician or PI.
• Working at the division conducting the trial at any of the three study centres.
• Do not have a mobile phone that is suitable for the use of a research app.