Glycemic Index: How to Determine High vs Low-Glycemic Foods

Low glycemic index foods are better for your health than high glycemic foods.

The glycemic index (GI) is a numeric value assigned to foods based on how slowly or quickly they can increase your blood glucose levels. It is a rating system for carbohydrate-containing foods. Foods having a low GI are the ones that tend to release glucose slowly and steadily. By contrast, foods that fall high on the GI scale release glucose rapidly.

GI is assigned with reference to pure glucose that is arbitrarily given a GI of 100. Thus, if a food has a GI of 30, it means it will boost blood glucose by only 30% compared with pure glucose.

Based upon the GI value, foods are divided into three categories

• Low-GI foods: This refers to foods with a GI value of 55 or less. Low-GI foods include most fruits and vegetables, whole or minimally processed grains, beans, pasta, low-fat dairy products and nuts.
• Moderate-GI foods: Foods belonging to this category have a GI of 56 to 69. They include white potatoes, sweet potatoes, white rice, corn, couscous and breakfast cereals such as Mini-Wheats and Cream of Wheat.
• High-GI foods: Foods in this category have a GI of 70 or more. Foods with high GI include white bread, cakes, doughnuts, cookies, rice cakes, most crackers, bagels, croissants and most packaged breakfast cereals.

Are eggs a low-glycemic food?Eggs are a low-glycemic food. Additionally, they have a satiating effect making the person feel fuller longer. Thus, eggs have the benefit of limiting calorie itake as well. Low-glycemic foods help manage weight and reduce the risk of diabetes, heart diseases, obesity, nerve damage and certain cancers.

Other foods with a low glycemic index (GI) include

• Most vegetables such as green peas, cabbage, lettuce, spinach, collards, kale, cucumbers, broccoli, zucchini, bok choy and artichokes
• Certain fruits such as apples, pears, plum, avocado, olives, unripe banana, dried apricots, oranges, coconut, cranberries and blueberries
• Mushrooms
• Whole or minimally processed grains such as barley, whole wheat, oat and rice bran cereals, sourdough bread and wheat tortilla
• Nuts and nut butters 
• Seeds such as pumpkin, chia, sunflower and flax seeds
• Poultry such as chicken and turkey
• Fish and shellfish
• Meat such as beef and pork
• Oils such as extra virgin olive oil and canola oil
• Fats such as lard, shortening and butter
• Mayonnaise
• Dairy and dairy-substitute products such as milk, plain yogurt, cheese and soy milk

Although low-glycemic foods do not cause erratic blood sugar spikes, it is important to watch calories while consuming them as well. For example, fats and oils are low-glycemic foods, but too much of these will add calories to the diet and may cause more harm in the long run.

High-glycemic foods have a glycemic index (GI) of 70 or more. These foods are not bad if consumed in low to moderate amounts. High-glycemic foods tend to cause more rapid and higher blood sugar spikes than low-glycemic foods. Blood sugar spikes are considered bad because a high blood sugar level places a higher demand for the insulin release on the body. This may cause a substantial drop in blood sugar levels after the spike. The dips cause more hunger, carbohydrate cravings and weakness. Frequent consumption of high-GI foods is associated with higher insulin levels in the body and consequent beta cell fatigue (reduced insulin production by beta cells).

High-glycemic foods are associated with a higher risk of diabetes, heart disease, obesity, high blood pressure and certain cancers such as colorectal cancer.

Foods with high GI include white bread, cakes, candies, doughnuts, cookies, rice cakes, most crackers, bagels, croissants and most packaged breakfast cereals.