Inclusion Criteria:

• T1DM or T2DM of duration ≥ 5 years.
• HbA1C > 7.5 %.
• Able to provide written informed consent before participating in the study.
• Able to communicate adequately with the investigator and to comply with the requirements for the entire study.

Exclusion Criteria:

• Severe nausea or vomiting precluding study assessments.
• Use of medications that alter GI motility; e.g., narcotics or medications with significant anticholinergic effects. Subjects using metoclopramide or erythromycin will be enrolled provided it is safe to hold these medications for 48 hours before study procedures.
• Patients likely to be treated with medications that directly affect gastrointestinal motility; e.g., pramlintide or GLP-1.
• Patients likely to undergo major procedures; e.g., pancreas transplantation, dialysis or kidney transplantation within the next 3 months.
• No nonsteroidal anti-inflammatory drugs (NSAIDS) or aspirin should be taken in the week before this test; this is an agent of exclusion only if medically safe to do so.
• Patients who are allergic to eggs, wheat or milk or unwilling to consume these products.
• For female patients who will participate in the validation arm of the study, pregnancy or breast feeding.