Effects of Pizza Leavening Process on Postprandial Glucose Response in Patients With Type 1 Diabetes

Pizza is a typical food from Southern Italy. Its consumption is spreading worldwide. However, eating pizza is often challenging for type 1 diabetes patients due to its high glycemic index and the sustained and prolonged postprandial hyperglycaemia. Therefore, modifications of the composition and manufacturing processes able to improve the effects of pizza on postprandial blood glucose response would be well accepted.

The purpose of this study is to compare in patients with type 1 diabetes the postprandial glucose response to the consumption of three types of pizza, obtained with different leavening techniques.

Patients with type 1 diabetes treated with continuous subcutaneous insulin infusion for at least 6 months and HbA1c less than 8.0%, will be recruited at the diabetes care unit of the Federico II University teaching hospital.

The intervention will be preceded by a one-week run-in period during which participants will undergo continuous glucose monitoring (CGM) to optimize basal infusion rate and insulin-to-glycemic load ratio. Then, according to a randomized crossover design, participants will consume at home at dinner-time in random order in three different days over a 3-week period:1) a long-leavened (60 h) pizza composed of sourdough and a flour mix; 2) a short-leavened (5 h) pizza composed of sourdough and a flour mix; 3) a traditional pizza composed of brewer's yeast and refined wheat flour. Over the three experimental weeks, participants will undergo CGM, wearing their sensors 7 days/week.

The pizza- meals will be similar in energy content and macronutrient composition. The pizza dough will be prepared in a specialized factory and kept under vacuum until use. Participants will be also provided with tomato sauce and extra-virgin olive oil in the exact amount needed to prepare pizza.