At months 0, 2, and 4, patients will be assessed for weight, body cell mass, patient-reported physical activity level, and dietary intake (by 24-hour dietary recall). At months 2 and 4, they will also be assessed for compliance with study regimen. Patients who complete their 4 month follow up visit will be provided with a 30 day supply of the caloric supplement of their choice (Peptamen or NuBasics) and a 30 day supply of the study multivitamin supplement.