The Food Insulin Index (FII) is a novel system of ranking foods based on the insulin response in healthy subjects relative to an isoenergetic reference food. The goal of this thesis was to explore the clinical application of the FII to mealtime insulin dosing in type 1 diabetes.
Carbohydrate counting is the current gold standard method for determining prandial insulin dose in type 1 diabetes, however only 7 studies assessing the efficacy of carbohydrate counting for glycaemic control in people with type 1 diabetes could be identified. Meta-analysis revealed there was no significant improvement in HbA1c with carbohydrate counting over general dietary advice and/or usual care (-0.35%, p = 0.096). This study highlighted the need for research into alternative strategies to improve the accuracy of the mealtime insulin dose.
The FII reveals a notable insulin demand for foods high in protein and fat, nutrients that would normally be disregarded for mealtime insulin dosing with traditional carbohydrate counting. Compared with carbohydrate counting, the FII algorithm was able to reduce mean blood glucose level for six foods high in protein (5.7 +/- 0.2 mmol/L vs 6.5 +/- 0.2 mmol/L, p = 0.003), without significantly increasing the risk of hypoglycaemia (p = 0.155).
In the first randomised, controlled trial of the real-world application of the FII, the FII was at least as good as carbohydrate counting for glycaemic control in 26 adults with type 1 diabetes (HbA1c FII: -0.1 ± 0.1% vs CC: -0.3 ± 0.2%, p = 0.855), with a trend towards reduced risk of hypoglycaemia in the FID counters after 12 weeks.
Collectively, these studies offer exciting insights into the potential of the FII for optimising glycaemic control in type 1 diabetes. Until a cure can be found, the potential for clinically significant enhancements in glycaemic control offer people with diabetes greater wellbeing through a reduced burden of disease and decreased risk of long-term diabetes complications.