Eating right can lower your blood sugar, LDL-cholesterol, and triglyceride levels. Healthy foods in the right amounts can help to keep your glucose levels stable, too, and slow or prevent diabetes complications. The glycemic index (GI) classifies carbohydrates based on how quickly and how much they boost blood sugar compared to pure glucose. Choose low-GI foods are best for keeping blood sugar levels down.
The glycemic index or glycaemic index (GI) is a measure of how quickly blood glucose levels (i.e., blood sugar) rise after eating a particular type of food. Glucose (the defining standard) has a glycemic index of 100. The effects that different foods have on blood glucose levels vary considerably. The glycemic index estimates how much each gram of available carbohydrate (total carbohydrate minus fiber) in a food raises a person's blood glucose level following consumption of the food, relative to consumption of pure glucose.
A practical limitation of the glycemic index is that it does not take into account the amount of carbohydrate actually consumed. A related measure, the glycemic load, factors this in by multiplying the glycemic index of the food in question by the carbohydrate content of the actual serving. Watermelon has a high glycemic index, but a low glycemic load.
Another practical limitation of the glycemic index is that it does not measure insulin production due to rises in blood sugar. As a result, two foods could have the same glycemic index, but produce different amounts of insulin. Likewise, two foods could have the same glycemic load, but cause different insulin responses. Furthermore, both the glycemic index and glycemic load measurements are defined by the carbohydrate content of food. For something like steak, which has no carbohydrate content but can nonetheless trigger an insulin response due to high protein intake, GI and GL provide little information. When the two glycemic measurements cannot be used for comparison, the "insulin index" may be more useful.
The material on this site is for informational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any medical condition. Consult a licensed medical professional for the diagnosis and treatment of all medical conditions and before starting a new diet or exercise program. If you have a medical emergency, call 911 immediately.