Visit Schedule

After baseline sampling, participants consume a standardised 200 kcal breakfast shake and then undergo repeated breath VOC and capillary glucose sampling. Participants fast from midnight and avoid alcohol for 24 hours before the study visit. Participants avoid toothpaste and mouthwash for at least one hour before the first measurement and should avoid cosmetics if possible. Baseline assessments at 08:00 include questionnaires, body composition, and HbA1c measurement if needed.