Publication:

Effects of a low-carbohydrate diet in adults with type 1 diabetes: an interventional study protocol

Background Type 1 diabetes (T1D) is an autoimmune condition characterised by pancreatic beta cell destruction and absolute insulin deficiency. The varying impact of dietary factors on blood glucose levels is well-known, yet there remains a lack of consensus surrounding the optimal dietary approaches to achieve glycaemic control in T1D. The aim of this research is to assess the efficacy of a low-carbohydrate (LC) diet in adults with T1D. We will set out to determine whether significant differences in T1D management outcomes exist between a LC diet and habitual diets higher in carbohydrate. Our primary hypothesis is that a LC diet will result in improved T1D management compared to habitual diets higher in carbohydrates.

Methods This is a 28-week single arm within-participant intervention study involving a 4-week control period, a 12-week intervention period and a 12-week follow-up. We plan to recruit 20 adults (18-60 years) with T1D (duration ≥6 months) who have suboptimal glycaemic control (HbA1c>7.0%). The primary outcome is haemoglobin A1c (HbA1c) and secondary outcomes include glycaemic variability, frequency of hypoglycaemia, total daily insulin, and quality of life. This LC diet will start at 50 g of digestible carbohydrate per day and then there will be opportunity to increase or decrease within a broader range of 25-75 g/day according to individual blood glucose levels and personal preference.  Participants will meet individually with the study dietitian for a total of six fortnightly sessions to receive dietary instruction, strategies, and education. Participants will continue to work with a member of their usual diabetes care team for specific advice regarding insulin management.

Conclusions Current dietary management strategies for T1D appear to be lacking in effect and additional dietary therapies, including LC diets, require urgent consideration. Therefore, an interventional study investigating a patient-led LC dietary approach will be of important clinical relevance for healthcare practitioners and may help to better inform clinical practice guidelines for T1D management.Trial Registration: https://www.anzctr.org.au/ACTRN12621000764831.aspx