Participants in 1 group will be given standard care (for the next 42 days) for allogeneic BMT at the ambulatory center. Participants in the other group will be given standard care (for the next 45 days) for allogeneic BMT at the ambulatory center as well as nutritional assessment and intervention. If your envelope has a label that says "standard," you will receive standard care only. If your envelope has a label that says "intervention," you will receive standard care as well as nutritional assessment and intervention.