The Glycemic Index (GI) is a measure of how quickly blood sugar levels are raised after a food is consumed. It should be used as part of a healthy diet, especially for those who are trying to lose weight or control their diabetes.
When you constantly eat foods that have a high glycemic index, your blood sugar levels will consistently be raised to high levels.
This is because these foods digest very quickly in your stomach and intestines, which causes your blood sugar to spike.
When this happens, your pancreas releases a lot of insulin to “mop up” the blood sugar. Once your blood sugar levels are lowered again, you feel hungry and eat more. You then repeat the cycle. Excessive insulin causes the body to store too much fat, leading to obesity.
GLYCEMIC INDEX
The GLYCEMIC INDEX (GI) is a ranking of the extent to which foods raise blood sugar levels, compared with pure glucose or white bread. (1)
The index, which ranges from 0–100, uses glucose as a reference value (glycemic index of 100).
Slowly absorbed carbohydrates, which are digested gradually, have a low GI rating (55 or below). You can find these in vegetables and most fruits and legumes.
Glycemic index chart(2):
| FOOD | Glycemic index (glucose = 100) |
| HIGH-CARBOHYDRATE FOODS | |
| White wheat bread* | 75 ± 2 |
| Whole wheat/wholemeal bread | 74 ± 2 |
| Speciality grain bread | 53 ± 2 |
| Unleavened wheat bread | 70 ± 5 |
| Wheat roti | 62 ± 3 |
| Chapatti | 52 ± 4 |
| Corn tortilla | 46 ± 4 |
| White rice, boiled* | 73 ± 4 |
| Brown rice, boiled | 68 ± 4 |
| Barley | 28 ± 2 |
| Sweet corn | 52 ± 5 |
| Spaghetti, white | 49 ± 2 |
| Spaghetti, wholemeal | 48 ± 5 |
| Rice noodles† | 53 ± 7 |
| Udon noodles | 55 ± 7 |
| Couscous† | 65 ± 4 |
| BREAKFAST CEREALS | |
| Cornflakes | 81 ± 6 |
| Wheat flake biscuits | 69 ± 2 |
| Porridge, rolled oats | 55 ± 2 |
| Instant oat porridge | 79 ± 3 |
| Rice porridge/congee | 78 ± 9 |
| Millet porridge | 67 ± 5 |
| Muesli | 57 ± 2 |
| FRUIT AND FRUIT PRODUCTS | |
| Apple, raw† | 36 ± 2 |
| Orange, raw† | 43 ± 3 |
| Banana, raw† | 51 ± 3 |
| Pineapple, raw | 59 ± 8 |
| Mango, raw† | 51 ± 5 |
| Watermelon, raw | 76 ± 4 |
| Dates, raw | 42 ± 4 |
| Peaches, canned† | 43 ± 5 |
| Strawberry jam/jelly | 49 ± 3 |
| Apple juice | 41 ± 2 |
| Orange juice | 50 ± 2 |
| VEGETABLES | |
| Potato, boiled | 78 ± 4 |
| Potato, instant mash | 87 ± 3 |
| Potato, french fries | 63 ± 5 |
| Carrots, boiled | 39 ± 4 |
| Sweet potato, boiled | 63 ± 6 |
| Pumpkin, boiled | 64 ± 7 |
| Plantain/green banana | 55 ± 6 |
| Taro, boiled | 53 ± 2 |
| Vegetable soup | 48 ± 5 |
| DAIRY PRODUCTS AND ALTERNATIVES | |
| Milk, full fat | 39 ± 3 |
| Milk, skim | 37 ± 4 |
| Ice cream | 51 ± 3 |
| Yoghurt, fruit | 41 ± 2 |
| Soy milk | 34 ± 4 |
| Rice milk | 86 ± 7 |
| LEGUMES | |
| Chickpeas | 28 ± 9 |
| Kidney beans | 24 ± 4 |
| Lentils | 32 ± 5 |
| Soya beans | 16 ± 1 |
| SNACK PRODUCTS | |
| Chocolate | 40 ± 3 |
| Popcorn | 65 ± 5 |
| Potato crisps | 56 ± 3 |
| Soft drink/soda | 59 ± 3 |
| Rice crackers/crisps | 87 ± 2 |
| SUGARS | |
| Fructose | 15 ± 4 |
| Sucrose | 65 ± 4 |
| Glucose | 103 ± 3 |
| Honey | 61 ± 3 |
Data are means ± SEM. * Low-GI varieties were also identified. † Average of all available data. | |
Foods low on the glycemic index tend to release glucose slowly and steadily. Foods with a high glycemic index tend to raise blood sugar levels very quickly.
It’s always best to choose alternatives with lower glycemic index scores, when you do eat high-glycemic foods—mix them with protein or other low-GI foods so they release their energy more slowly.
Whole grains and high-fibre foods take longer to digest than their refined counterparts, so they can help keep your blood sugar level steady.
Foods with fat can make a food’s glycemic index lower. For example, chocolate (which is high in fat) has a medium-low GI because of its makeup. This shows us that we should not only focus on the glycemic index of foods but also pay attention to other aspects like health benefits
Low-GI diets, when combined with other healthy eating habits, can often be a successful weight-loss strategy.
The Glycemic Index is a measure of how quickly blood sugar levels are raised after a food is consumed.
Knowing the GI of your favourite foods will help you plan meals that are both healthy and satisfying.
This technique will help you do just that!
