The Breakfast Rise, Education and Knowledge Study in Children and Young People Who Have Type 1 Diabetes (T1D): The BREAK Study

This is a quantitative study. Dexcom CGM data will be collected for the period of recording. Participants will be asked to test three breakfast meals on two occasions and submit a postprandial questionnaire after each test meal to confirm it has been tested. The postprandial period will be three hours following the end of the breakfast test meal. The test meal recipes will be provided by the chief investigator. The dietary composition of the meals has been analysed using the a dietary analysis programme. The glycaemic index and load of the meals is estimated from this programme which uses available date from the international tables of glycaemic index and glycaemic loads (Atkinson et al. 2008; 2021). Most foods were based on average composition across different brands. For the added fibre bread used in test meal 3, an average of three known brands was used calculated by the chief investigator. The meals will be taken in the home environment with the food provided by the families. The participants will be asked to take the test meal on a day when their CGM reading is between 4-10mmol/l and when there has been no nocturnal hypoglycaemia on the night before the planned test. The participants will act as their own control. They will be asked to complete a postprandial questionnaire for control meals as well. The control meals will be there usual breakfast of choice. The study duration, commencing with the recruitment of the first participant and ending when data has been fully described, is anticipated to be two years.

Recruitment Paediatric diabetes dietitians, working across the UK, will be enrolled to help recruit participants and become principal investigators (PI) for their site.

Sample size The sample size power calculation is 64. This is based on using ANOVA repeated measures, within factors with four groups and measurements (3 test meals and control) with small effect size (0.15), P value 0.05 and power 0.80 and correlation among repeated measure of 0.5. The drop rate of clinical trials is often over 40%. Therefore, the aim is to recruit 90 participants to allow for this dropout rate and meet the sample size of 64. It may be possible to recruit this number of participants. There are approximately 29,000 children and young people living in the UK with T1D (Juvenile Diabetes Research Federation (JDRF), 2018). In the first phase of this study, 12 NHS sites were enrolled, and 96 children and young people were recruited to the study.

Methodology Baseline data

In order to make comparisons between relevant variables and glucose levels, the following baseline data will be collected from the dietitians and sent to the chief investigator, along with the artificial identifier on the Excel spreadsheet as discussed earlier at the stage of recruitment of participants: