Metabolic Effects of Subchronic Dopamine D2 Receptor Blockade by Haloperidol in Healthy Humans

Inclusion Criteria: * Healthy men * 20 kg/m2 \< BMI \< 26 kg/m2 * Age 20-40 years * FPG \< 6 mmol/L Exclusion Criteria: * FPG \> 6 mmol/L * BMI \> 26 kg/m2 * Psychiatric disorders and/or use of antipsychotic or antidepressants drugs at present or in the past. * A positive family history of schizophrenia * Any significant chronic disease * Renal, hepatic or endocrine disease * Use of medication known to influence lipolysis and/or glucose metabolism * Total cholesterol \> 7mmol/L and/or triglycerides \> 2 mmol/L * Recent weight changes or attempts to loose weight (\> 3 kg weight gain or loss, within the last 3 months) * Difficulties to insert an intravenous catheter * Smoking (current) * Severe claustrophobia (ventilated hood) * Recent blood donation (within the last 2 months) * Recent participation in other research projects (within the last 3 months), participation in 2 or more projects in one year * Extensive sporting activities (more than 10 hours of exercise per week)