The Glycemic Index, or GI, draws attention to the fact that not all carbs are created equal and ranks them on a scale from 0 to 100 by ability to spike blood glucose levels and thus insulin release.
It is a measure of the amount of blood glucose released in two hours after ingestion of a food. Edibles with a low GI (55 or less)are slowly digested, only gradually raise blood glucose and insulin levels and do not raise blood lipid levels.
They also allay hunger- and are now thought to protect against diabetes and heart disease. Example : GI of an apple - 38, baked potato - 85.
Another good gauge of the biological value of a food is its glycemic load.
It represents both quality and quantity and idicates the effect on blood glucose levels of any food eatne by measuring its GI times the amount of carbohydrate in a serving.
Watermelon has has a high glycemic index (72)but only a small glycemic load (3.6)because it contains relatively little carbohydrate (and lots of water).
A baguette slice is a different story, with a GI of 95 and a GL of 48.
A GL over 20 is considered high and worth avoiding.
