Effect of NN5401 in Japanese Subjects With Type 1 Diabetes

Inclusion Criteria: * Japanese subject * Type 1 diabetes mellitus (as diagnosed clinically) for at least 12 months * Body mass index (BMI): 18.0-28.0 kg/m\^2 (both inclusive) Exclusion Criteria: * Loss of more than 400 mL blood (inclusive) in total with in the last 12 weeks or more than 200 mL blood (inclusive) in total within the last 4 weeks prior to screening * Smoker (defined as a subject who is smoking more than 5 cigarettes (not inclusive 5) or the equivalent per day) * Not able or willing to refrain from smoking and use of nicotine gum or transdermal nicotine patches during the inpatient period