Validation of the food insulin index in lean, young, healthy individuals, and type 2 diabetes in the context of mixed meals: an acute randomized crossover trial.
BACKGROUND
The Food Insulin Index (FII) is a novel classification of single foods based on insulin responses in healthy subjects relative to an isoenergetic reference food.


OBJECTIVE
Our aim was to compare day-long responses to 2 nutrient-matched diets predicted to have either high or low insulin demand in healthy controls and individuals with type 2 diabetes (T2DM).


METHODS
Twenty adults (10 healthy adults and 10 adults with T2DM) were recruited. On separate mornings, subjects consumed either a high- or low-FII diet in random order. Diets consisted of 3 consecutive meals (breakfast, morning tea, and lunch), matched for macronutrients, fiber, and glycemic index (GI), but with 2-fold difference in insulin demand as predicted by the FII of the component foods. Postprandial glycemia and insulinemia were measured in capillary plasma at regular intervals over 8 h.


RESULTS
As predicted by their GI, there were no differences in glycemic responses between the 2 diets in either group (mean ± SEM; healthy: 6.2 ± 0.2 compared with 6.1 ± 0.1 mmol/L · min, P = 0.429; T2DM: 9.9 ± 1.3 compared with 10.3 ± 1.6 mmol/L · min, P = 0.485). Compared with the high-FII diet, mean postprandial insulin response over 8 h was 53% lower with the low-FII diet in healthy subjects (mean ± SEM; incremental AUCinsulin 31,900 ± 4100 pmol/L · min compared with 68,100 ± 11,400 pmol/L · min, P = 0.003) and 41% lower in subjects with T2DM (mean ± SEM; incremental AUCinsulin 11,000 ± 1800 pmol/L · min compared with 18,700 ± 3100 pmol/L · min, P = 0.018). Incremental AUCinsulin was statistically significantly different between diets when groups were combined (P = 0.001).


CONCLUSIONS
The FII algorithm may be a useful tool for reducing postprandial hyperinsulinemia in T2DM, thereby potentially improving insulin resistance and β-cell function. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12611000654954.
Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and.
Kirstine J
KJ
Bell
Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and.
Jiansong
J
Bao
Department of Statistics, Macquarie University, Sydney, Australia.
Peter
P
Petocz
Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and.
Stephen
S
Colagiuri
Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, Charles Perkins Centre, and the School of Molecular Bioscience, University of Sydney, Sydney, Australia, and jennie.brandmiller@sydney.edu.au.
Jennie C
JC
Brand-Miller
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D005260:Female; D038321:Glycemic Index; D064368:Healthy Volunteers; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D062407:Meals; D008875:Middle Aged; D019518:Postprandial Period; D015203:Reproducibility of Results; D016896:Treatment Outcome; D055815:Young Adult
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D007328:Insulin
glycemia; healthy subjects; insulinemia; nutrition; type 2 diabetes