Carbohydrates Under Target for Type 1 Diabetes Management

Recently, there has been an increased interest in limiting carbohydrates (CHO) intakes for improving long-term health. Low CHO (\<30% energy from CHO) and very low CHO high fat (VLCHF; 10% CHO, 75% Lipid) diets are being advocated among people living with diabetes given their almost immediate favorable impact on post-prandial blood glucose levels and on hemoglobin A1c that have been reported by users. Adoption of these diets are met with reluctance by healthcare professionals due to the lack of information on their safety. Concerns include the impact on hypoglycemia frequency and glucagon response to hypoglycemia, diabetic ketoacidosis, lipid profile, liver function insulin dose adjustments when adopting them in the context of type 1 diabetes (T1D). Through a series of interviews, people with diabetes following a VLCHF reported that the lack of support from HCPs often leads to hiding the fact that they have adopted a VLCHF diet. This is an important source of concern that can lead to additional safety issues.

The goal is to fill an important knowledge gap about the effectiveness, benefits and risks of low CHO and VLCHF diets for people with T1D. The primary objective is to compare the percentage of TIR of adults with T1D following a low-CHO diet or a VLCHF diet versus a control diet for 12 weeks. The secondary objectives are (1) to evaluate efficacy of glucagon in correcting hypoglycemia in the context of restricted carbohydrates intakes; (2) to evaluate changes in HbA1c at 12 weeks and glucose fluctuations and % of time in hypoglycemia at 6 weeks and 12 weeks of control diet, low-CHO diet or VLCHF diet; (3) to compare key cardiometabolic risk factors (body composition, blood lipids, blood pressure and liver inflammatory markers and function) at 6 weeks and 12 weeks of control diet, low-CHO diet or VLCHF diet; (4) to evaluate the effect of restrictive CHO diets (low-CHO and VLCHF) on the composition of the intestinal microbiota (optional).


Eligibility Criteria:
Inclusion Criteria:

* Men and women \> 18 years old
* Duration of T1D \> 12 months
* On intensive insulin therapy
* Own a smartphone or tablet to use two mobile applications for nutritional and physical activity tracking: Keenoa and Piezo: Achieve the Guidelines!

Exclusion Criteria:

* Already following a low-CHO diet (\<30% CHO)
* Type 2 diabetes or other form of diabetes
* Known gastroparesis (clinical diagnosis)
* Advanced kidney disease (eGFR \< 50 mL/min)
* Known significant liver disease (e.g. cirrhosis, active hepatitis, liver transplantation)
* Recent (\<6 months) major cardiovascular event (e.g. myocardial infarction, cerebrovascular accident, major revascularization, etc.)
* Pregnancy (ongoing or planned in the next 6 months)
* Breastfeeding (ongoing)
* Recent severe hypoglycemia episodes (BG \<2.8 mmol/L or assistance from a third party) or ketoacidosis (\<6 weeks)
* Claustrophobia or presence of metal devices/implants in the body
* Recent (\<6 weeks) or planned (next 6 months) modification in insulin treatment
* Recent (\<6 weeks) or planned (next 6 months) modification in cardiometabolic drugs for blood pressure and/or lipids. These drugs must remain stable all along the trial
* Off label adjunct therapy with SGLT-2 inhibitors (Forxiga®, Invokana® or Jardiance®)
* Recent (\<6 weeks) or planned (next 6 months) modification of adjunct therapy (Metformin, Glumetza®, Victoza®, Trulicity® and Ozempic®)