Glycemic index (GI)
A 0–100 score for how quickly a carbohydrate food raises blood glucose, compared with pure glucose.
The glycemic index ranks carbohydrate foods by how fast and how high they push blood glucose, on a scale where pure glucose is 100. Low-GI foods (55 or under) digest slowly and produce a gentle rise; high-GI foods (70 and above) spike it quickly.
GI is measured per fixed amount of carbohydrate, so it doesn't account for how much you eat. That's what glycemic load adds. GI also shifts with ripeness, processing, and what else is on the plate, so treat published numbers as a guide, not a rule.