What does the glycemic index measure?

The glycemic index specifically measures how quickly a food causes an increase in blood sugar levels after consumption. This measurement is particularly important for individuals managing their blood glucose levels, such as those with diabetes or those looking to control their weight. Foods with a high glycemic index raise blood sugar quickly, leading to rapid spikes in insulin, while those with a lower index result in slower, more gradual increases. This information helps people make informed dietary choices, aiming for steady blood sugar control rather than rapid fluctuations.

The other options do not relate to the glycemic index; fat, fiber, and protein contents of food affect nutritional intake and health in various ways but are not measures of how quickly food impacts blood sugar levels.