This trial is conducted in Japan. The aim of this trial is to investigate the bioequivalence of two formulations of biphasic insulin aspart 50 (NN-X14Mix50) in healthy Japanese subjects.

Inclusion Criteria:

• Considered generally healthy upon completion of medical history and physical examination, as judged by the Investigator or Sub-Investigator.
• Body Mass Index (BMI) between 19-29 kg/m^2 (inclusive)
• Fasting plasma glucose between 3.8-6.0 mmol/L (both inclusive)

Exclusion Criteria:

• Clinically significant abnormal haematology, biochemistry or urinalysis screening tests, as judged by the Investigator or Sub-Investigator
• Any serious systemic infectious disease that had occurred during the 4 weeks prior to the screening, as judged by the Investigator or Sub-Investigator
• Any inter-current illness that might affect blood glucose, as judged by the Investigator or Sub-Investigator
• Hepatitis B or C, or HIV (human immunodeficiency virus) positive
• Subjects with a first degree relative with diabetes mellitus
• History of or presence of diabetes, cancer or any clinically significant cardiac, respiratory, metabolic, renal, hepatic, gastrointestinal, endocrinological, dermatological, venereal, haematologic, neurologic, or psychiatric diseases or disorder
• Subjects who consumed more than 28 units of alcohol per week or who had a significant history of alcoholism or drug/chemical abuse
• Subjects who smoked more than 5 cigarettes per day
• Subjects who had taken part in strenuous exercise within 7 days prior to the screening