Many of the traditional foods of the holiday season—fresh bread, stuffing, mashed potatoes, and pie—are packed with carbohydrates. Some carbs cause blood sugar to soar more than others. The glycemic index is a helpful tool for choosing good carbs during the holidays and every day, reports the November 2012 Harvard Health Letter.

Blood sugar and insulin levels rise every time you eat something containing carbohydrates. How high they rise, and how fast, depends on the food. White rice has almost the same effect as eating pure sugar—a quick, high spike in blood sugar and insulin followed by an equally fast drop. Brown rice and other whole grains have slower, smaller effects.

The glycemic index captures these changes by rating the effect of a specific amount of a food on blood sugar compared with the same amount of pure glucose. The lower the glycemic index, the slower the rise in blood sugar. "Glycemic index categories can be very helpful for people trying to choose a healthy diet," says Dr. Frank Hu, professor of nutrition at the Harvard School of Public Health. Over the past three decades, researchers have measured the glycemic index of several thousand foods. You can find a list of the glycemic index values of 100 foods on the Harvard Health website.

Read the full-length article: "Choosing good carbs with the glycemic index"