On the test days, the response to a protein meal will be examined and subjects will receive a mixture of amino acids which are a little bit heavier than normal, called stable isotopes. Subjects will also ingest a sugar drink to assess gut permeability. In total, approximate 120 ml of blood will be drawn on each test day to assess outcome measures. The investigators' will also collect urine over these 8 hours, and cancer subjects are asked to collect a fecal sample the day before the test day.