Two products were studied: white bread (Butter Toast®, Golden Toast, Wittenberg, Germany) and whole grain bread (1688 Mehrkorn®, Harry-Brot, Schenefeld, Germany). One portion (containing 50 g digestible carbohydrates) was eaten immediately before the beginning of the test in the morning after an overnight fast of at least 10 h. Before testing, participants ate as usual on the previous day without a standard meal and refrained from consuming alcohol and exercising for 72 h. A 200-ml glucose drink (Accu-Chek Dextrose O.G.-T. Saft®, Roche Diabetes Care, Mannheim, Germany), containing also 50 g of carbohydrates, was used as the reference product.

One day prior to the study beginning, participants were equipped with a CGM system (FreeStyle Libre®, Abbott Diabetes Care, Alameda, CA, USA). This CGM system provides glucose recordings every 15 min over a period of 14 days. The glucose data were downloaded manually by a scan with a handheld device.

On the second day of the study, participants consumed portions of these three test products containing 50 g of available carbohydrate on 3 separate days without a washout period. The products were tested in random order at the same time of the morning after a 10 h overnight fast. Venous blood samples were collected at 0, 15, 30, 45, 60, 75, 90, 105 and 120 min postprandial by inserting an intravenous cannula into a forearm vein. Capillary blood samples were obtained through finger pricking. Blood glucose levels in these samples were measured with a high quality SMBG system (ContourXT/Contour next, Ascensia Diabetes Care, Leverkusen, Deutschland, Germany).

postprandial glycemic changes after consuming different carbohydrate containing foods

after consuming different carbohydrate containing foods