Threonine Requirement in Adult Males With Crohn's Disease Using IAAO

The goal of the current study is to measure the requirement for threonine in patients with CD using the IAAO method and compare the requirement to previously determined threonine requirement estimated in young adults using the IAAO technique. It is hypothesize that the requirement for threonine in patients with CD will be higher than the threonine requirement previously determined in young adults using the IAAO method. Up to 10 clinically stable patients with CD will be recruited from the IBD Clinic at Mt. Sinai Hospital, Toronto, and subsequently followed up at the Clinical Research Center (CRC), The Hospital for Sick Children (SickKids), Toronto, Canada. Before the study begins, the participants will be required to visit the CRC (Room 5500 Hill Wing, The Hospital for Sick Children) for a pre-study assessment of their height, weight, fat mass, fat free mass, resting metabolic rate and medical history. These assessments will take about 3 hours to complete. They will need to have been fasted for 10 hours prior to the pre-study assessment. The pre-study assessment is needed to calculate their dietary requirements for the study, and to assess health status. After signing the consent form, the subjects will complete the screening procedures (height, weight, fasting blood sample and medical history questionnaire, BIA, Skinfold and calorimetry). Each study will consist of a 2-day adaptation period to a prescribed diet in accordance with the energy requirement of the subject and 1-study day. The diet will provide an adequate amount of protein, of 1 g protein/kg/d. The 2-day adaptation period is to allow the body to adapt to an adequate amount of protein as it has been shown that protein kinetics is altered without it. Dietary intakes during this time will be provided in the form of lactose-free milk shakes (Scandishake) with added carbohydrate (SolCarb) and protein (beneprotein) to meet the subjects' requirement. Following the 2 days of adaptation is the study day where