Effects of Low-calorie Sweetened Beverage Restriction in Youth With Type 1 Diabetes

Eligible participants will be scheduled for a baseline visit. During the week prior, they will be instructed to continue usual dietary habits and complete an online photo-assisted food record, with parental assistance. At the baseline visit, height and weight will be measured, a spot urine sample will be collected, and a blood draw will be performed. Participants will have their CGM data for the past two weeks downloaded. In a subset of participants, an abdominal MRI will also be performed.

Subjects will then be randomized to either: 1) low-calorie sweetener (LCS) restriction or 2) continuation of usual LCS intake (control). All participants (both groups) and their parent will undergo a brief, 20-minute orientation where the PI and study dietitian will provide an introduction to the study, instructions on completing food records, education on CGM. Those in the intervention group will be given sample replacement beverages and a brochure on avoiding LCS to take home which will include a list of specific foods and beverages containing LCS to avoid during the study. Participants in the control group will be counseled on healthy eating as those in the intervention group (in accordance with standard dietary guidance for T1D management), with the exception of information and resources for avoiding LCS.

In both groups, text messages will be sent to parents 3X/week with reminders that their child should avoid LCS or continue usual intake, per randomization. Adherence will be monitored through collection of spot-urine samples for measurement of sucralose and ace-K concentrations. daily text message beverage logs completed by the parent, and photo-assisted food records with parent assistance in Weeks 0, 1, 6, and 12. During Week 6, participants and their parent will attend a mid-intervention telemedicine booster visit, during which the PI and/or study RA will reinforce the intervention and remind participants to mail back a spot urine sample using materials provided by the study team at baseline. Participants will be reminded of the study instructions, including the importance of inserting the DEXCOM G6 sensor (provided by study team) at the beginning of Week 11.

At the end of Week 12, participants and their parent will return for follow-up. Participants will have their CGM data downloaded using DEXCOM Clarity™ software. Height and weight will be measured and a second blood draw performed. Those who had an MRI at the baseline visit (n=30) will undergo a second abdominal MRI. Those randomized to the intervention will be purposefully sampled and asked to complete a ~20 minute qualitative interview and ~5 minute satisfaction survey, together with their parent, about their study experience and the challenges of LCSB restriction.