A good guide to good carbs: The glycemic index

Choosing low glycemic foods can curb blood sugar spikes and lower risk of diabetes

If you have diabetes, you know all too well that when you eat carbohydrates, your blood sugar goes up. The total amount of carbs you consume at a meal or in a snack mostly determines what your blood sugar will do. But the food itself also plays a role. A serving of white rice has almost the same effect as eating pure table sugar — a quick, high spike in blood sugar. A serving of lentils has a slower, smaller effect.

Picking good sources of carbs can help you control your blood sugar and your weight. Eating healthier carbohydrates may help prevent a host of chronic conditions, especially diabetes, but it is also associated with a lower risk of heart disease and certain cancers.

One way to choose foods is with the glycemic index (GI). This tool measures how much a food boosts blood sugar.

The glycemic index rates the effect of a specific amount of a food on blood sugar compared with the same amount of pure glucose. A food with a glycemic index of 28 boosts blood sugar only 28% as much as pure glucose. One with a GI of 95 acts like pure glucose.

Glycemic index chart

Choose low glycemic foods

Using the glycemic index is easy: choose foods in the low GI category instead of those in the high GI category (see below), and go easy on those in between.

• Low glycemic index (GI of 55 or less): Most fruits and vegetables, beans, minimally processed grains, pasta, low-fat dairy foods, and nuts.
• Moderate glycemic index (GI 56 to 69): White and sweet potatoes, corn, white rice, couscous, breakfast cereals such as Cream of Wheat and Mini Wheats.
• High glycemic index (GI of 70 or higher): White bread, rice cakes, most crackers, bagels, cakes, doughnuts, croissants, most packaged breakfast cereals.

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