The glycemic index (abbreviated GI) is one of the key characteristics that help divide food into healthy and harmful. Foods with a low glycemic index are acceptable with proper nutrition, while foods with a high GI lead to weight gain.
In particular, the regular consumption of large volumes of carbohydrate foods with a high glycemic index (the so-called “fast carbohydrates”) disrupts the metabolic processes in the body, provoking the development of diabetes and affecting obesity.
What is the glycemic index?
The glycemic index is a measure of the ability of food carbohydrates to be converted into glucose. In turn, glucose uptake requires insulin. If the mechanism of insulin production fails, too much sugar accumulates in the blood, creating a health risk.
In this case, the GI takes into account only the maximum value of the increase in blood glucose. For example, carrots are high glycemic foods but create a low glycemic load (having few carbohydrates).
It is also important to remember that the glycemic index can vary even for the same person at different times of the day – since the body’s ability to process carbohydrates is closely related to the level of activity (and the involvement of skeletal muscles in metabolism).
Low GI foods – what are the benefits?
Foods with a low glycemic index contain vegetable fiber, which not only normalizes the production of insulin but also helps to reduce bad cholesterol. In addition, since fiber is found predominantly in plants, it provides the body with vitamins and minerals.
In total, the glycemic index scale consists of 100 units – where 100 is the maximum and 0 is the minimum. Low GI is considered to be below 35 units. Note that this indicator cannot be found at home – it is calculated in the laboratory based on a blood test after consuming the product.
In addition, the glycemic index is determined exclusively for carbohydrate foods. Although meat and other protein foods lead to the production of insulin, the GI theory does not take this into account – for this reason, it is gradually being replaced by the insulin index (AI) theory.
How is it calculated?
The glycemic index is a comparison of the rate at which glucose rises after eating a serving of food containing approximately 50 g of carbohydrates with 50 g of pure glucose. The low GI of a product means that when it is eaten, the blood sugar level rises smoothly, without sharp peaks.
A sharp surge in blood glucose, in turn, leads to the active production of insulin – with the help of this hormone, the carbohydrates eaten are absorbed by the body. First, they go to the needs of basic metabolism (or are stored in muscle glycogen), and in excess, they are sent to fat reserves.
Separately, we note that the glycemic index is not a universal indicator. An individual’s response to the carbohydrates in a food depends on their overall health and level of daily physical activity – as well as the food combination they eat.
How to reduce GI?
Ultimately, the glycemic index (that is, the rate at which carbohydrates from a particular food are converted into glucose) depends on the cooking method. For example, undercooked durum wheat pasta will have a lower GI than soft pasta made from regular white flour.
Also, the glycemic index is affected by the salt content, the presence of lactose in the composition, and even the temperature during consumption (cold food is absorbed a little more slowly than hot). Plus, the acidity of food (adding vinegar) also affects the decrease in the glycemic index.
Foods with a high glycemic index
Foods with a high glycemic index are foods that contain simple carbohydrates with a high absorption rate. They quickly give their calories to the blood in the form of glucose, overflowing the body with excess energy. If this energy is not currently needed in the muscles, it is sent to fat stores.
However, it is not the high GI foods themselves that are harmful, but their excessive consumption is harmful. For example, immediately after a workout, carbohydrates will benefit the athlete’s body, since their energy will provide a direct stimulus for muscle growth and recovery. Gainers with maltodextrin and isotonics work on this principle.
The dangers of high GI foods
The combination of regular consumption of high-GI foods and a sedentary lifestyle is one of the key causes of a number of diseases. We are talking about both diabetes mellitus and an increase in the level of bad cholesterol. At the same time, the most harmful type of fast carbohydrate is fructose – the body cannot use the excess of its calories otherwise than to store it in fat.
| Product | Glycemic Index (GI) |
| Maltodextrin | 100 – 105 |
| White bread | 100 |
| Sweet buns | 95 |
| Pancakes | 95 |
| Potato (baked) | 95 |
| Rice noodles | 95 |
| Canned apricots | 95 |
| Instant rice | 90 |
| Honey | 90 |
| Instant porridge | 85 |
| Carrots (boiled or stewed) | 85 |
| Cornflakes | 85 |
| Mashed potatoes, boiled potatoes | 85 |
| Sports isotonics (Powerade, Gatorade) | 80 |
| Muesli with nuts and raisins | 80 |
| Sweet pastries (waffles, donuts) | 75 |
| Pumpkin | 75 |
| Watermelon | 75 |
| Melon | 75 |
| Rice porridge with milk | 75 |
| Millet | 70 |
| Carrots (raw) | 70 |
| Chocolate bars (Mars, Snickers) | 70 |
| Milk chocolate | 70 |
| Sweet carbonated drinks (Coca-Cola) | 70 |
| Pineapple | 70 |
| Dumplings | 70 |
| Soft wheat noodles | 70 |
| White rice | 70 |
| Potato chips | 70 |
| Sugar (white or brown) | 70 |
| Couscous | 70 |
| Manka | 70 |
Foods with an average glycemic index
Products with an average glycemic index – from buckwheat to muesli with sugar – are an example of the fact that it is impossible to divide food into healthy and harmful, based solely on such a parameter as the rate of absorption of carbohydrates. In the end, it’s the total that matters.
If regular and excessive consumption of foods with an average GI negatively affects the overall blood sugar level and disrupts metabolic processes in the body (including the mechanism for producing the hunger hormone leptin), then moderate consumption of such foods (for example, oatmeal) can positively affect the organism.
| Product | Glycemic Index (GI) |
| Wheat flour | 65 |
| Orange juice (packaged) | 65 |
| Preserves and jams | 65 |
| Black yeast bread | 65 |
| Marmalade | 65 |
| Muesli with sugar | 65 |
| Raisins | 65 |
| Rye bread | 65 |
| Jacket boiled potatoes | 65 |
| Whole wheat bread | 65 |
| Canned vegetables | 65 |
| Pasta with cheese | 65 |
| Thin crust pizza with tomatoes and cheese | 60 |
| Bananas | 60 |
| Ice cream | 60 |
| Long grain rice | 60 |
| Industrial mayonnaise | 60 |
| Oatmeal | 60 |
| Buckwheat (brown, roasted) | 60 |
| Grapes and grape juice | 55 |
| Ketchup | 55 |
| Spaghetti | 55 |
| Canned peaches | 55 |
| Shortbread | 55 |
Foods with a low glycemic index
Low-GI foods are primarily natural foods that contain a lot of fiber. In fact, foods containing complex carbohydrates have a low glycemic index – most cereals (buckwheat, quinoa, bulgur), seeds, nuts, and green vegetables.
Fruits, although they have a low glycemic index, still increase the level of insulin in the blood, which is dangerous for diabetics. In this case, we are talking about the insulin index – it is increasingly replacing the glycemic index, as it is more accurate.
| Product | Glycemic Index (GI) |
| Sweet potato | 50 |
| Green buckwheat (without pre-roasting) | 50 |
| Quinoa | 50 |
| Basmati rice | 50 |
| Cranberry juice (no sugar) | 50 |
| Oranges | 50 |
| Kiwi | 50 |
| Mango | 50 |
| Brown rice | 50 |
| Apple juice (no sugar) | 50 |
| Grapefruit | 45 |
| Bulgur | 45 |
| Fresh orange juice | 45 |
| Whole grain toast | 45 |
| Dried figs | 40 |
| Pasta cooked “al dente” | 40 |
| Carrot juice (no sugar) | 40 |
| Dried apricots | 40 |
| Prunes | 40 |
| Wild (black) rice | 35 |
| Fresh apple | 35 |
| Fresh plum | 35 |
| Fresh quince | 35 |
| Low fat natural yoghurt | 35 |
| Beans | 35 |
| Fresh nectarine | 35 |
| Pomegranate | 35 |
| Fresh peach | 35 |
| Tomato juice | 30 |
| Fresh apricot | 30 |
| Pearl barley | 30 |
| Brown lentils | 30 |
| Green bean | 30 |
| Fresh pear | 30 |
| Tomato (fresh) | 30 |
| Fat-free cottage cheese | 30 |
| Yellow lentils, peas | 30 |
| Blueberries, lingonberries | 30 |
| Bitter chocolate (70% or more cocoa) | 30 |
| Milk (any fat content) | 30 |
| Passion fruit | 30 |
| Mandarin (fresh) | 30 |
| Blackberry | 25 |
| Cherry | 25 |
| Green and red lentils | 25 |
| Golden beans | 25 |
| Raspberry (fresh) | 25 |
| Red ribes | 25 |
| Soy flour | 25 |
| Wild strawberry | 25 |
| Pumpkin seeds | 25 |
| Gooseberry | 25 |
| Peanut butter (no sugar) | 20 |
| Antichoke | 20 |
| Eggplant | 20 |
| Soy yogurt | 20 |
| Almond | 15 |
| Broccoli | 15 |
| Cabbage | 15 |
| Cashew | 15 |
| Celery | 15 |
| Bran | 15 |
| Brussel sprouts | 15 |
| Cauliflower | 15 |
| Chilli | 15 |
| Fresh cucumber | 15 |
| Hazelnut, pine nut, pistachio, walnut | 15 |
| Asparagus | 15 |
| Ginger | 15 |
| Mushrooms | 15 |
| Vegetables marrow | 15 |
| Onion | 15 |
| Pesto | 15 |
| Leek | 15 |
| Olives | 15 |
| Peanut | 15 |
| Rhubarb | 15 |
| Tofu | 15 |
| Soya | 15 |
| Spinach | 15 |
| Avocado | 10 |
| Leaf salad | 10 |
| Chia seeds, flaxseed | 10 |
| Parsley, basil, vanillin, cinnamon, oregano | 10 |
The glycemic index measures how quickly the carbohydrates in a food are absorbed by the body and increase blood sugar levels. The scale consists of 100 units, where 0 is the minimum and 100 is the maximum. High GI foods release their energy quickly, while low GI foods are high in fiber and digest slowly.