The aim of this project is to investigate the physiological effects of intake of long-chain fatty acids (LCFA) and medium-chain fatty acids (MCFA) in patients with Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD) and healthy individuals

Male and female MCADD patients and healthy individuals will be included in this study which is a randomized intervention study in a cross over design consisting of two separate test days.

The study involves two test days of four hours each, during which the participants ingests either medium-chain fatty acids (MCFA) or long-chain fatty acids (LCFA) in the form of triacylglycerol oils. The order of fatty acid oils ingested is determined by randomization.

Inclusion Criteria MCADD patients:

• Male or female
• Age between 18-80 years old
• Diagnosed Medium-chain acyl-CoA dehydrogenase deficiency (MCADD

Inclusion Criteria Healthy Participants:

• Male or female
• Age between 18-80 years old

Exclusion Criteria both MCADD patients and healthy participants:

• Diabetes
• Kidney- or liver disease
• Use of beta blockers or diuretics
• Pregnant, lactating or planning to become pregnant within the study period
• Regular intake of substantial amounts of coconut oil, palm kernel oil or any other source abundant in MCFA
• Ongoing cancer treatment
• Metabolic or absorptive disorders, gastric bypass operation, or use of medication affecting metabolism or food absorption
• Inability, physically or mentally, to comply with the procedure required by the study protocol as evaluated by the primary investigator, study manager or clinical responsible