The purpose of this study is to determine whether copeptin levels are affected by food intake.

Inclusion Criteria:

• Aged over 18 years

Exclusion Criteria:

• Intake of any kind of medication (except birth control pill)
• BMI >30 kg/m2
• Evidence of any acute illness
• History of chronic illness
• Pregnancy
• Known galactosemia or maltose malabsorption
• Baseline glucose level >5.5 mmol/l Baseline sodium level <135 mmol/l or >145 mmol/l

healthy adults