- Reviewed by Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
The glycemic index is a value assigned to foods based on how quickly and how high those foods cause increases in blood glucose levels. Foods low on the glycemic index (GI) scale tend to release glucose slowly and steadily. Foods high on the glycemic index release glucose rapidly. Low-GI foods tend to foster weight loss, while foods high on the GI scale help with energy recovery after exercise, or to offset hypo- (insufficient) glycemia.
Long-distance runners would tend to favor foods high on the glycemic index, while people with pre- or full-blown diabetes would need to concentrate on low-GI foods. Why? People with type 1 diabetes can't produce sufficient quantities of insulin, and those with type 2 diabetes are resistant to insulin. With both types of diabetes, faster glucose release from high-GI foods leads to spikes in blood sugar levels. The slow and steady release of glucose in low-glycemic foods helps maintain good glucose control.
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About the Reviewer
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
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