Understanding the glycemic index and glycemic load and their practical applications.

We have introduced the study of synthesis pathways using two experiments: 1-the determination of the glycemic index (GI) of some foods and the effects of fiber and fat on the GI; 2-the determination of blood glucose levels after the ingestion of meals with high and low glycemic loads (GL). After a practice assembly, when the foods and meals that were eaten by the students were tallied, the students were divided into groups. At the next class, three members of each group, who had fasted for 8 hr, ingested 50 g of carbohydrate in food or a meal. After ingestion, the blood glucose was measured with a portable device every 30 min for a period of 2 hr. Discussion of the data obtained in experiment 1 allowed the students to understand the mechanism of action of insulin and to understand how the GI, as presented in the literature, is determined. The students also concluded that the addition of fiber to food reduces the glycemic response even with high GI foods, and these results could be a useful strategy for diet prescription. Discussion of experiment 2 allowed the students to understand that the amount of food intake is a determining factor for the glycemic response and subsequent release of insulin. These experimental observations allowed the students to transfer theoretical knowledge to their daily lives very easily. The students approved the classes and felt encouraged to study the synthesis pathways and metabolic integration in the fed state.