Method of Food Preparation Influences Blood Glucose Response to a High-carbohydrate Meal

The aim of this study was to establish the blood glucose response to different cooking methods of pasta. Participants consumed three identical meals in a random order that were freshly cooked (hot), cooled and reheated. Blood glucose concentrations were assessed before, and every 15 minutes after ingestion of each meal for 120 minutes. There was a significant interaction between temperature and time (F_{(8.46-372.34)} = 2.75, p = 0.005), with the reheated (90 minutes) condition returning to baseline faster than both cold (120 minutes) and hot conditions. Blood glucose AUC was significantly lower in the reheated (703 ± 56 mmol L^-1 min^-1) compared with the hot condition (735 ± 77 mmol L^-1 min^-1, t(92) = -3.36, pbonferroni = 0.003), with no significant difference with the cold condition (722 ± 62 mmol L^-1 min^-1). To our knowledge, the current study is the first to show that reheating pasta causes changes in post-prandial glucose response, with a quicker return to fasting levels in both the reheated and cooled conditions compared with the hot condition. The mechanisms behind the changes in post-prandial blood glucose seen in this study are most likely related to changes in starch structure and how these changes influence glycaemic response.