Glucose-dependent insulinotropic polypeptide (GIP) is a gut-derived incretin hormone that affects glucose, lipid and bone metabolism. Secretion of GIP into the blood stream from enteroendocrine cells is stimulated bu nutrients in the gut lumen and results in potentiation of glucose stimulated insulin secretion from the pancreas. The objective of this study is to investigate the physiology of GIP(1-30)NH2 in humans with insulin secretion as the primary endpoint. Furthermore the effects on on plasma/serum levels of glucagon, C-peptide, glucose, bone markers (CTX and P1NP) will be measured.

Inclusion Criteria:

• Healthy men of Northern European descent
• BMI: 19-25 kg/m2
• Stable body weight (±5%) in the last three months

Exclusion Criteria:

• Treatment with medication or dietary supplements that cannot be paused for 12 hours
• More than 14 units of alcohol per week or abuse of narcotics
• Established liver disease and/or plasma alanine aminotransferase (ALT) ≥3 × normal value and/or INR outside the normal range
• Renal impairment (eGFR <60 ml/min/1.73 m2)
• Severe arteriosclerotic heart disease or severe heart failure (NYHA group III or IV)
• Low blood count (haemoglobin <8.3 mol/l)
• Special diet or planned body weight change before the trial period
• First-degree relatives with diabetes
• Participation in other clinical experiments with medication
• Any disease/condition that the investigators estimate disturbing for the participation in the experiment