Final answer:
The glycemic index measures how quickly a food raises blood glucose, while glycemic load also considers the carbohydrate content. Insulin lowers blood glucose by storing it as glycogen in the liver, and glucagon raises blood glucose by promoting glycogenolysis in the liver. Monitoring the response to insulin helps manage diabetes mellitus.
Step-by-step explanation:
Glycemic Index vs. Glycemic Load
The glycemic index (GI) is a measure of how quickly foods containing carbohydrates raise blood glucose levels. It doesn't take into account the amount of carbohydrates present in a serving of food. On the other hand, glycemic load (GL) considers both the GI and the carbohydrate content in a serving of food to give a more comprehensive picture of a food's impact on blood glucose levels.
When a diet is rich in carbohydrates, it can lead to hyperglycemia if the carbohydrates have a high GI. Conversely, a poor carbohydrate diet, which is likely to consist of foods with a low GI, can create relative hypoglycemia. This is because fats and oils are more reduced compared to glycogen, releasing more energy when oxidized. Furthermore, glycogen is hydrophilic and thus absorbs water, which increases its mass compared to fats and oils.
Glucose homeostasis is regulated by the hormones insulin and glucagon. Insulin facilitates the transport of glucose into cells and promotes the storage of glucose as glycogen in the liver, lowering blood glucose levels. Glucagon, in contrast, stimulates glycogenolysis (the breakdown of glycogen into glucose) in the liver, particularly under hypoglycemic conditions, to raise blood glucose levels.
Understanding the response to insulin is crucial for managing diabetes mellitus. For example, in an insulin tolerance test as depicted in Graph-A, a normal or insulin-responsive individual exhibits a quick decrease in blood glucose level following an insulin injection, which later returns to normal as glucagon is secreted. This pattern differs in individuals with diabetes, who may exhibit varying responses based on whether they are insulin-dependent or if their diabetes is due to excessive insulin antagonists.