Inclusion Criteria:  Age: 12-18 years Clinical diagnosis of type 1 diabetes Duration of diabetes > 1 r Multiple daily injections or continuous subcutaneous insulin infusion. Home glucose testing 4 times per day or continuous glucose monitor. Hemoglobin A1c levels will be ≤ 10.5% History of adherence to insulin administration, carbohydrate counting.  Exclusion Criteria:  Duration of type 1 diabetes for less than 1 year Medical conditions other than type 1 diabetes or treated hypothyroidism Medications other than insulin, levothyroxine or oral contraceptives for birth control Antihypertensive medications, lipid lowering medications, or anti-hyperglycemic agents other than insulin. Acute viral and bacterial illnesses are not exclusionary, but we will take a health history at baseline and at the time of any study visit and if a recent illness has occurred we will delay testing until the individual is symptom free for 1 week and off and treatment for the illness. Hospital admission for diabetic ketoacidosis in the last year