Enabling an objective measure of diet, covering individual foods as well as different dietary patterns, in large-scale studies has great potential; this would for instance improve our understanding of the role of diet in long-term disease prevention and care in people with type 2 diabetes.

The overarching aim of this study is to develop a framework from which dietary intake can be assessed, both as single foods and dietary patterns, in cohort studies among people with type 2 diabetes. This study is performed to assess which collection strategy best reflects long-term dietary intake and to weigh this up against feasibility and costs in large-scale studies.

This is a 4-week observational study that will be carried out in adults with newly diagnosed type 2 diabetes living in Denmark.

The aim is to recruit up to 60 participants aged 18-75. The participants will be asked to record and weight their habitual food intake on 8 days spread out within a one-month time period. They will also be asked to complete one 24-hour urine collection the day before study start and provide 7 morning spot urine samples on the subsequent mornings after filling in the food diary.

At the start of the study period participants will undergo a DXA scan and have a blood sample taken. At the end of the study period a second blood sample will be drawn and a hair sample will also be collected. Incomplete 24-hour collections will be judged based on predicted 24-hour creatinine excretion from lean body mass and actual creatinine excretion being in the interval from 0.8-1.2, which corresponds to ~20% on each side of the expected excretion. Participants falling outside this interval will be asked to complete a new 24-hour urine sample. As the primary aim of this study is validation, it is important that the samples provided are as complete as possible.

In the one-month period between visits to the study center, a subset of volunteer participants (up to 20 participants) will be asked to consume extra portions of fermented dairy products (skyr, ymer and yogurt) 1-2 days before the spot urine sample to be able to validate markers for specific foods. All participants in the subcohort will consume each of the foods one time before a spot urine and one time be asked to abstain intake of dairy products as a control. Foods will be provided to the participants.

Note: the study has ended with fewer participants than expected due to problems with recruitment. We will analyse these samples and work on samples from another study to answer our initial research questions.

Inclusion Criteria:

• Newly diagnosed type 2 diabetes (within the last 5 years from study start) (self-reported)
• 18.5-35.0 kg/m2 BMI
• More than 1cm of natural hair on the head
• Have not dyed their hair in the previous 6 months
• Willing to record dietary intake up to 9 days
• Willing to have blood samples drawn two times
• Willing to collect up to two 24-hour urine samples and 7 spot urine samples at home and be able to store them in their own freezer in provided tubes and boxes throughout the one-month study
• Have no intention to radically change dietary and physical activity habits during the study period
• Owning a smartphone with internet connection
• Can speak and read Danish

Exclusion Criteria:

• Pregnant or lactating women
• Diagnosed with any chronic or communicable diseases including liver diseases (e.g., active hepatitis B and C infections), liver cirrhosis, severe psychiatric illness or any other clinical condition that makes the subject ineligible according to the clinically responsible medical doctor (except type 2 diabetes) (self-reported).
• History of cancer within the past 5 years (except adequately-treated localized basal cell skin cancer or in situ uterine cervical cancer)
• Diagnosed with any CVD event (e.g., myocardial infarction, revascularization procedure or stroke) within the past 2 years
• Unintentional weight loss >20% during the last 6 months
• Regular intake of prescription medication (except diabetes medication, blood pressure-lowering medication, cholesterol-lowering medication, mild antidepressants or contraceptive pills)
• Concurrent participation in another trial
• Not willing to sign the Informed consent form (ICF)
• Not willing to comply with the all the trial procedures

Adults with newly diagnosed type 2 diabetes that are otherwise generally health and willing to participate in the study.

Once the project is finished, data will by fully anonymised and shared with other researchers.

After completion of the main study project.

Will be uploaded on University of Copenhagen data sharing platform. More information to come.