This trial is conducted in Europe. The aim of this trial is to evaluate the efficacy and safety of biphasic insulin aspart 30 in subjects with type 1 or type 2 diabetes.

Inclusion Criteria:

• Subjects with insulin requiring type 1 or type 2 diabetes for at least 24 months
• Current treatment with human insulin (either premix of short and long/intermediate acting insulin) in a twice daily treatment regimen preparation and/or self-mix for at least 12 months
• Body mass index (BMI) below or equal to 35.0 kg/m^2
• HbA1c below or equal to 11.0%

Exclusion Criteria:

• Total daily insulin dose at least 1.4 IU/kg
• Treatment with oral hypoglycaemic agents within the month prior to inclusion
• Recurrent severe hypoglycaemia (as judged by the investigator)
• Active proliferative retinopathy
• Impaired renal function with creatinine at least 150 mcmol/l (1.7 mg/dl)
• History of pancreatitis