Towards Objective Dietary Assessment in Large-scale Studies

Overview

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.