Low carbohydrate diet and improved glycaemic control in a patient with type one diabetes

We present the case of an adult female with type 1 diabetes, whose HbA1c was trending at 58 mmol/mol (7.5%) for the past 3 years. In August 2016, she reduced her total daily carbohydrate intake to 30–50 g and adjusted her other macronutrients to compensate for the calorific deficit. Her HbA1c fell to 34 mmol/mol (5.3%) by January 2017 and average daily blood glucose readings decreased significantly from 10.4 to 6.1 mmol/L. Moreover, she observed a marked reduction of average daily glucose variability. Notably, there were no significant episodes of hypo- or hyperglycaemia and her lipid profile remained static. Subjectively, she described an improvement in her quality of life and the dietary transition was extremely well tolerated. We discuss these findings in detail and the potential clinical benefits for patients with type 1 diabetes that can be gained by following a low carbohydrate diet. LEARNING POINTS: A low carbohydrate diet was found to substantially reduce HbA1c values and blood glucose (BG) variability, as well as causing a significant reduction in average daily glucose values in a patient with T1DM. Although further research is warranted, low carbohydrate diets in patients with T1DM have the potential to positively impact long-term morbidity and mortality through reduction of BG variability and average daily BG values. The diet was well tolerated and not associated with any adverse effects within this study.