A novel smartphone insulin dosing app to incorporate fat and protein into mealtime insulin dosing for children and adolescents with Type 1 diabetes using insulin pumps.

Participants will be using an insulin calculator called optimAAPP that will incorporate fat and protein amounts along with carbohydrate in order to calculate an appropriate insulin dose -The intervention will be personalised based on the participants current diabetes management. This will be done during the run-in period which will take place over 2 weeks before each intervention. This will also work as a wash-out period - Each participant will be provided with a fat and protein education session that has been developed by the diabetes team. Participants will also be demonstrated on use of the insulin calculator through a face to face education session along with instructional videos to watch - For 3 months the participant will use their current method of insulin calculation for their meals and for the other 3 months they will use our insulin calculator to determine their insulin needs for each meal. - They will attended several education sessions with our Senior diabetes dietitian in order to ensure they are given appropriate and effective information. - They will have face to face sessions with the research team at the beginning, middle and end of the trial. Along with regular phone contact with a research coordinator throughout. - This trial will take place in a free living environment. 1. During the run-in period will involve daily BGL monitoring and consultation with endocrinologist to ensure the participant is receiving suitable insulin doses 2. Fat and protein education will be provided by a dietitian 3. Education session will be roughly an hour 4. We have made the instructional videos mandatory to ensure the education session will go smoothly and can come with any questions they may have 5. The instructional videos were designed specifically by our team for this study 6. The education session has two standardised work sheets to determine participant competency with fat and protein. Depending on participants knowledge with this will determine how much education they will require until considered proficient by the dietitian. 7. Face to face sessions will be used for fat and protein education. Initial set up and training on how to use optimAAPP. Along with sensor insertion and surveys when required. 8. We are able to analyse data from the app to determine how often they are using to to calculate insulin and this can be compared with pump downloads.