Low cArbohydraTe dIeT and aUtomated Insulin Delivery System for Type 1 DiabetEs (LATITUDE)

Inclusion Criteria:

1. Men and women ≥ 18 years old
2. Duration of T1D or latent autoimmune diabetes in adults (LADA) ≥ 12 months
3. On automated insulin delivery system for ≥ 3 months
4. Own a smartphone or tablet to use the mobile application: Keenoa
5. Willing to share personal CGM data during the study period
6. Reporting daily food intake >3350 kJ (1200 kcal)
7. Time in closed-loop mode during run-in period > 70%

Exclusion Criteria:

1. Self-reported having a diet with < 35% energy from carb.
2. Seldom (<20% of scenario) or never count carbohydrate intake.
3. Self-reported clinically significant nephropathy (eGFR < 30 ml/min/1.73m2, planned or on dialysis or already followed by a nephrologist), or retinopathy (e.g., proliferative retinopathy with ongoing active treatment such as laser photocoagulation or planned surgery)
4. Recent (< 6 months) acute macrovascular event (e.g., acute coronary syndrome or cardiac surgery).
5. Self-reported significant liver disease (e.g. cirrhosis, active hepatitis, liver transplantation)
6. Self-reported uncontrolled thyroid disease (unless stable treatment for 8 weeks at inclusion with TSH within target range).
7. Self-reported one or more severe hypoglycemic episodes within two weeks of screening.
8. Self-reported one or more severe hyperglycemic episodes requiring hospitalization in the last 3 months.
9. Anticipated therapeutic change (including change of insulin type [switch to biosimilar is not considered as insulin change] and/or type of CGM sensor, insulin pump or AID between admission and end of the study.
10. To limit risk of interference for CGM accuracy: anticipated need to use acetaminophen during the study period at a dose above 1g every 6 hours and current or anticipated use of Hydroxyurea.
11. Plan to go abroad in a foreign country during the study period for a duration > 4 weeks.
12. Pregnancy (ongoing or current attempt to become pregnant).
13. Breastfeeding.
14. Using regular insulin (Entuzity U500, Novolin ge Toronto or Humulin R).
15. Current use of glucocorticoid medication (except low stable dose and inhaled steroids and stable adrenal insufficiency treatment e.g., Cortef®).
16. Current use of agents affecting gastric emptying (Motilium®, Victoza®, Ozempic®, Trulicity®, Byetta® and Symlin®) as well as oral anti-diabetic agents (Metformin, Prandase®, DPP-4 inhibitors) unless at a stable dose for 3 months and without anticipated change during the study.
17. Current use of SGLT-2 inhibitors unless at a stable dose for at least 3 months, without anticipated change during the study and appropriate ketone testing is performed.
18. Other serious medical illnesses which likely interfere with study participation or with the ability to complete the study by the judgment of the investigator.
19. In the opinion of the investigator, a participant who is unable or unwilling to complete the study.