A randomized, double-blinded (for insulin type), single centre, crossover design young adult study, on 20 subjects with type 1 diabetes (T1D), aged 18 to 25 (inclusive) years, measuring time in glucose values within 3.9 - 10 mmol/l (70-180 mg/dl) under supervision of DreaMed Glucositter using either faster-acting insulin Aspart (Fiasp®, European Medicines Agency number EMEA/H/C/004046) or normal acting insulin Aspart.