Circadian cycles, metabolism, and nutrition are intimately linked, and the timing of meals play an important role in synchronizing peripheral circadian rhythms. There are little data describing the influence of nocturnal feeds on sleep, metabolism, and overall health in hospitalized children. To evaluate this association, the investigators will conduct a single-center, randomized, non-blinded controlled trial that will test the impact of nocturnal enteral/parenteral nutrition on patient outcomes.

HSCT provides a potential cure for children and adults with high risk and relapsed malignancy, immune deficiency, and other fatal illnesses. Circadian cycles, metabolism, and nutrition are intimately linked, and the timing of meals play an important role in synchronizing peripheral circadian rhythms; however, the standard of care for HSCT recipients is to deliver continuous feeds (either enterally or parenterally).

The objective of this study is to evaluate the influence of the timing of feeding on sleep and metabolism in HSCT subjects. The investigators hypothesize patients receiving feeds during daytime hours (0800-2000) in comparison to continuous (24 hours), will have improved sleep efficiency, decreased blood glucose, insulin, and triglycerides over patients who receive feeding overnight. The aim of this study is to evaluate the influence of the timing of feeds on sleep, metabolism, and outcomes in HSCT subjects.

Inclusion Criteria:

• Patients >/= 12 months of age undergoing HSCT and receiving a myeloablative preparative regimen

Exclusion Criteria:

• Prior history of hypoglycemia, diabetes mellitus, metabolic disease, or other requirement for continuous nutrition