A Trial Investigating the Pharmacokinetic Properties of FIAsp in Children, Adolescents and Adults With Type 1 Diabetes

Inclusion Criteria: * Male or female aged 6-64 years (both inclusive) at the time of signing informed consent * Type 1 diabetes mellitus (as diagnosed clinically) for at least 12 months * Body mass index (BMI) for children and adolescents (male and female) between the 3rd and 97th BMI percentile and for adults equal to or below 28.0 kg/m\^2 Exclusion Criteria: * Subject who has donated any blood or plasma in the past month or more than 500 mL within 3 months prior to screening * Smoker (defined as a subject who is smoking at least one cigarette, cigar or pipe daily) * Not able or willing to refrain from smoking and use of nicotine substitute products during the inpatient period