Which concept measures how fast sugar from food enters the bloodstream?

• A. Glycaemic index
• B. Dietary fiber
• C. Caloric density
• D. Protein quality

Answer: (A)

The main idea being tested is how quickly sugar from food appears in the bloodstream, which is captured by the glycaemic index. The glycaemic index (GI) is a value that ranks carbohydrate-containing foods by how rapidly they raise blood glucose after eating. Foods with a high GI cause a rapid spike in blood sugar, while those with a low GI produce a slower, more gradual rise. GI is determined by giving a portion containing a fixed amount of available carbohydrate to people and measuring their blood glucose response over about two hours, then comparing it with a reference food.

The other options don’t measure this rate of glucose entry. Dietary fiber affects digestion and can slow absorption but isn’t a measure of how fast glucose enters the blood. Caloric density is about energy per gram, not absorption speed. Protein quality relates to amino acid composition, not carbohydrate absorption.