The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels, and have proven benefits for health. Low GI diets have been shown to improve both glucose and lipid levels in people with diabetes (type 1 and type 2). They have benefits for weight control because they help control appetite and delay hunger. Low GI diets also reduce insulin levels and insulin resistance.
The glycemic load of a food tells how much eating that food raises blood glucose. It is a similar concept as the glycemic index, except it takes serving sizes into account. The formula is to take the number of grams of carbohydrate in the serving, multiply by the glycemic index, and divide by 100. Theoretically, if a food has glycemic load of one point, it would raise the blood sugar as much as one gram of glucose.
An awareness of foods’ Glycemic Index can help you control your blood sugar levels, and by doing so, may help you prevent heart disease, improve cholesterol levels, prevent insulin resistance and type-2 diabetes, prevent certain cancers, and achieve or maintain a healthy weight. A substantial amount of research suggests a low GI diet provides these significant health benefits.
After we eat carbohydrate-rich foods, our digestive process breaks them down and turns them into glucose, which enters bloodstream. (Since most proteins and fats are not turned into glucose , they have much less of an immediate effect on our blood sugar). Glucose in the bloodstream triggers the production of insulin, a hormone that helps glucose get into cells where it can be used for energy. Once our immediate energy needs have been met, extra glucose still remaining in the bloodstream will be stored in our muscles and liver for later use. If our muscle and liver stores of glucose are full, but we still have extra glucose floating around in our blood, then our body will store this excess sugar as fat.
| Food | Glycemic Index | One Serving | Glycemic Load |
| Coca-Cola | 63 | 250ml | 16 |
| Gatoraide | 78 | 250ml | 12 |
| Instant Oatmeal | 83 | 250ml | 30 |
| Cornflakes | 93 | 250ml | 23 |
| Quinoa | 53 | 150ml | 13 |
| White Rice | 89 | 150ml | 43 |
| Brown Rice | 50 | 150ml | 16 |
| Apple | 39 | 120ml | 6 |
| Banana | 62 | 120ml | 16 |
| Grapefruit | 25 | 120ml | 3 |
| Orange | 40 | 120ml | 4 |
| Pear | 38 | 120ml | 4 |
| Prune | 29 | 60ml | 10 |
| Raisins | 64 | 60ml | 28 |
| Watermelon | 72 | 120ml | 4 |
| Peanuts | 7 | 50ml | 0 |
| Black Beans | 30 | 150ml | 7 |
| Carrots | 35 | 80ml | 2 |
| Boiled White Potato(average) | 82 | 150ml | 21 |
| Sweet Potato | 70 | 150ml | 22 |
| Bread – French baguette | 95 | 1oz. | |
| Cereal Cheerios General Mills | 95 | 1 cup, 1oz. | |
| Cereal Rice Chex General Mills | 89 | 1 1/4 cup, 1oz. | |
| Cherries | 22 | 10 large, 3oz. | |
| Dark Chocolate(60%+ cocoa) | 22 | ||
| Crackers – saltine | 72 | ||
| Tofu frozen dessert low fat | 115 | 1/2 cup, 2 ozs | |
| Dates, dried | 103 | 5 or 1.4ozs | |
| Parsnips, boiled | 97 | 1/2 cup, 2.5 ozs. | |
| Sweet potato, peeled, boiled | 54 | 1/2 cup mashed, 3 ozs. | |
| White bread | 70 | 1 slice or 1oz | |
| Whole wheat bread | 69 | 1 slice or 1oz | |
| French fries | 75 | ||
| Grapenuts Cereal | 75 | 30g | 16 |
| Pineapple, raw | 66 | 120g | 6 |
| Ocean Spray Cranberry juice cocktail | 68 | 250ml | 24 |
| Beef steak, battered, fried, lean & fat eaten | 50 | 250ml | 3.6 |
A food is generally considered to have a high GI if it is rated above 60.
Individuals who have problems with maintaining proper blood sugar levels should restrict their selection to foods with a GI of 40 or less. These include those who have low blood sugar (hypoglycemia) and high blood sugar (hyperinsulemia) as well as those who have a high sensitivity to sugar. Sugar includes not just simple sugars, honey and maple syrup but also fruits, fruit juices, starchy vegetables and grain products or foods with a high glycemic index.
FYI…..Average GI of beer = 110.
Why doesn’t the GI chart include things like beef, chicken, fish, nuts, seeds, avocadoes, and berries? These foods contain no carbohydrate, or so little that their GI cannot be tested according to the standard methodology. Bear in mind that the GI is a measure of carbohydrate quality. Essentially, these types of foods, eaten alone, won’t have much effect on your blood glucose levels.