ProteIn Nutrition in Crohn's Disease

Muscles are essential for good quality of life. The investigators have shown that when children with Crohn's disease eat protein, only very little of it enters the muscles, leading to poor muscle growth and fatigue. The investigators want to find the reasons for this. The investigators will recruit 20 Crohn's disease patients and a matched group of healthy kids. The investigators will measure:

• Daily food intake and muscle strength.
• Protein absorption by giving our participants a milk protein test drink and take regular blood samples after.
• Muscle mass with MRI. This study will help understand how protein is handled in these patients.