Final answer:
The glycemic index measures the impact of foods on blood glucose levels, with lower index foods causing smaller changes, significant for diabetes management.
Step-by-step explanation:
The glycemic index is used to describe the impact that a specific food has on the amount of glucose in the blood. Foods with a high glycemic index increase blood glucose levels more rapidly than foods with a low glycemic index. This is an important consideration for individuals managing their diet in relation to blood sugar levels, particularly for those with diabetes mellitus, where it is essential to keep blood glucose levels under control to prevent hyperglycemia. By choosing foods with a lower glycemic index, individuals can help maintain steadier blood glucose levels, which is beneficial for both short-term and long-term health, including the management of Type 2 diabetes.