After the 30 minute blood sample, participants will be fed a breakfast consisting of a standardized protein content. They will also receive a lunch of similar protein content. Subjects with diabetes will be given a meal that is consistent with their treatment regimen. Subjects will be asked to administer their medications and check their blood sugar levels during the course of the study visit as they would normally do, in the manner prescribed by their treating physician. If the subject is at the CTRC past 6 PM, he/she will also receive dinner.