Page 92 - General Biochemistry

• In particular, foods containing high amounts of refined sugars have a high GI.
• Foods with a high GI will lead rapidly to hyperglycemia, which will cause a

hyperinsulinemia, which will cause a reactive hypoglycemia.

• On the other hand, foods high in fiber generally have a low GI.

Low GI = 55 or less
Medium GI = 56 - 69
High GI = 70 or more

Other factors that influence how quickly the carbohydrates in food raise
blood sugar include:

• Fiber content. Fiber shields the starchy carbohydrates in food immediate and

rapid attack by digestive enzymes. This slows the release of sugar molecules
into the bloodstream.

• Ripeness. Ripe fruits and vegetables tend to have more sugar than unripe ones,

and so tend to have a higher glycemic index.

• Type of starch. Sometimes some starchs are easier to break into sugar

molecules than other starches. The starch in potatoes, for example, is digested
and absorbed into the bloodstream relatively quickly.

• Fat content and acid content. The more fat or acid a food contains, the slower

its carbohydrates are converted to sugar and absorbed into the bloodstream.

• Physical form. Finely ground grain is more rapidly digested, and so has a higher

GI, than more coarsely ground grain.

• Measuring the Glycemic Index of Foods

• To determine the glycemic index of a food, volunteers are typically given a test

food that provides 50 grams of carbohydrate and a control food (white bread

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