This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Specific Aims: 1) To determine the change in A1C in a cohort of type 1 diabetic patients utilizing Timing of the premeal insulin administration compared to an equivalent control group in which Timing is not utilized. 2) To determine the change in postprandial glucose excursion (using Continuous Glucose Monitoring (CGM) in a cohort of type 1 diabetic patients on IIT when Timing is introduced into their therapeutic regimen compared to an equivalent control group in which Timing is not utilized. 3) To determine the change in blood 1,5-anhydroglucitol (1,5-AG) (using GlycoMark) over a 6-month period in a cohort of type 1 diabetic patients on IIT when Timing is introduced into their regimen compared to equivalent control group in which Timing is not utilized. 4) To determine change in incidence of hypoglycemia (using CGM) when Timing of the premeal insulin administration is introduced into an IIT regimen. 5) To assess improvement in QOL (using the Diabetes Quality of Life in Clinical Trials Questionnaire Revised (DQLCTQ-R) in volunteers utilizing Timing in their IIT regimen. Study will address the importance and benefits of Timing when incorporated into an IIT regimen, and the mechanism of this benefit.