This trial is conducted in Europe. The aim of this trial is to compare the exposure of liraglutide in young versus elderly healthy subjects.

Inclusion Criteria:

• Good general health as judged by the investigator, based on medical history, physical examination including 12-lead ECG (electrocardiogram), vital signs, and blood and urinary laboratory assessments
• Age, young subjects: age 18-45 years (both incl.)
• Age, elderly subjects: age at least 65 years
• Body Mass Index (BMI) 18-30 kg/m^2 (both incl.)
• Blood pressure, young: Diastolic 50-90 mmHg, systolic 90-140 mmHg
• Blood pressure, elderly: Diastolic 50-95 mmHg, systolic 92-160 mmHg

Exclusion Criteria:

• History of any clinically significant renal, hepatic, cardiovascular, pulmonary, gastrointestinal, metabolic, endocrine, haematological, neurological, psychiatric disease, or other major disorders that could interfere with the objectives of the trial, as judged by the investigator
• Impaired renal function
• Any clinically significant abnormal ECG (electrocardiogram)
• Active hepatitis B and/or active hepatitis C
• Positive HIV (human immunodeficiency virus) antibodies
• Febrile illness within 5 days prior to first administration of liraglutide
• History of alcoholism or drug abuse during the last 12 months
• Smoking of more than 10 cigarettes per day, or the equivalent for other tobacco products
• Habitual excessive consumption of methylxanthine-containing beverages and foods (coffee, tea, soft drinks such as cola, chocolate) as judged by the investigator