Box plots of breath VOCs over a course of nine hours. (a) Acetone, (b) 2-propanol, (c) pentanal, (d) ethanol, (e) dimethyl sulfide, (f) isoprene, and (g) limonene. The graphs on the left show the course over of the nine hours of the experiment for T1DM patients (n = 22), the graphs on the right show the corresponding data from healthy controls (n = 22). Data were normalized to the baseline value (before breakfast) to emphasize relative changes and minimize inter-individual variation. Lunch was taken after the measurement at the 330th minute. Dotted lines indicate intake of standardized meals. Asterisks (*) indicate statistically significant changes versus baseline (before breakfast) and hashes (#) indicate statistically significant changes versus the 330th minute (last measurement before lunch).