Glycemic index
Scientists have known for decades that sugary foods are absorbed quickly and cause a rapid increase in blood sugar, and until recently, it was thought that starches like potatoes, rice and dough raised blood sugar more slowly. However, in 1981, Dr. David Jurgens, a professor of nutrition at the University of Toronto, found that this view may not be correct. In working to find out which foods were best for people with diabetes, he discovered that some foods – like potatoes – actually caused a rapid rise in blood sugar, while some foods high in sugar seemed to raise blood sugar more slowly. This finding led to the introduction of the glycemic index (GI), which is a measure of the immediate rise in blood sugar after eating a carbohydrate food. Foods that are digested quickly and result in a rapid release of ketone groups that are already sugars are known as high glycemic index foods; foods that are digested more slowly are known as low glycemic index foods.
The initial index was based on the concentration of blood glucose after drinking 50 grams of pure ketogenic sugar. Researchers gave volunteers one food at a time, measured their blood sugar rise, and then determined the glycemic index of the food based on the rise in blood sugar caused by ketogenic sugars. The results were strange. The dieter’s staple – baked potatoes – actually had a higher glycemic index than sucrose; brown rice had a glycemic index of 55, as opposed to 40 for Mars bars, which were apparently harder to believe than brown rice, which is rich in fiber, vitamins and minerals, so the scientists rethought the study and soon found that their interpretation of the results was incorrect because they did not take food portions into account. They upgraded the whole system and came up with the glycemic load (GL). Glycemic load is still a measure of how many glycemic carbohydrates a food contains, but now it takes into account the portion size of the food. That is, foods such as watermelon have a high glycemic index because they contain starch and fruit sugars that cause a rapid rise in blood sugar, but they have a low glycemic load because the amount of sugar contained in one serving of the food is in fact very small. Diets with high glycemic index foods increase the risk of diabetes and heart disease, so the World Health Organization recommends a diet based on low glycemic index and low glycemic load foods.
There are several simple ways to avoid sugar overload by choosing low-glycemic index, low-glycemic load foods. In general, fiber-rich carbohydrates have a lower glycemic index than processed carbohydrates. Choose plenty of non-starchy vegetables, such as leafy greens, fava beans, legumes, salads, and tomatoes. Replace refined foods such as white bread, white rice, dough, and pasta with whole grain foods such as whole wheat bread, brown rice, oats, and barley. Limit starchy vegetables, such as potatoes, or mix starchy vegetables with lean protein and fiber, which release energy more slowly.
Glucose has a glycemic index of 100, as the glycemic index spikes immediately after consumption. Many foods are eventually converted to glucose, but if foods such as rice or bread are consumed, it takes longer for them to convert to glucose and for blood sugar to rise. Therefore, the lower the glycemic index, the better the food is for diabetics.
The glycemic index varies depending on the cooking method, for example, the glycemic index of semi-ripe rice is 47; the glycemic index of brown rice is 59; the glycemic index of cooked white rice is 88; the glycemic index of instant rice is 91. In addition, the time of harvesting plants also affects the glycemic index, for example, the glycemic index of bananas picked when unripe is 30; the glycemic index of ripe bananas is 62.
What is the “food glycemic index”? In fact, it is a valid index to measure the postprandial glycemic response of food. It refers to the percentage value of blood glucose response level in the body of food containing 50 grams of carbohydrates and an equivalent amount of glucose or white bread within a certain period of time (usually 2 hours), which is a comparative value reflecting the speed and ability of food to raise blood glucose compared with glucose. The glycemic index of glucose is usually set at 100.
Generally speaking, food glycemic index > 70 is high food glycemic index food, they are digested quickly after entering the stomach and intestines, with high absorption rate, fast glucose release, and high peak value of glucose entering the blood; food glycemic index < 55 is low food glycemic index food, they stay in the stomach and intestines for a long time, with low absorption rate, slow glucose release, low peak value of glucose entering the blood, and slow decline. The speed is slow.
Specifically, usually beans and dairy are always low or lower glycemic index foods, while cereals, potatoes and fruits often cause changes in glycemic index due to different varieties and processing methods, especially changes in the content of dietary fiber. Vegetables are definitely low in glycemic index, especially leaf and stem vegetables, because the content of carbohydrates does not exceed 6% and is rich in dietary fiber, so it has little effect on blood sugar. In fact, there are different kinds of food with low or high food glycemic index, the main difference lies in the carbohydrate content and different food processing, brands and formulas, it is difficult to say whether it is high or low from the type alone.
At the same time, food glycemic index is also affected by many factors, such as the type and structure of carbohydrates in food, the chemical composition and content of food, as well as the physical condition and processing of food, etc. If these differences are ignored, it will be difficult to control blood sugar smoothly.
First of all, during the cooking and processing of food, the glycemic index will be affected. For example, “degree of starch pasting” — during processing, starch granules swell to different degrees under the action of water and heat, and some starch granules even break down and decompose, becoming easily digestible, such as the longer the cooking time of porridge The longer the cooking time, the higher the glycemic index, the greater the impact on blood sugar. Another example is that “particle size” will also have an impact on it – the smaller the food particles, the easier they are to be absorbed by hydrolysis, and the higher the glycemic index, so the food should not be too fine.
Secondly, the composition of food will also have an impact on blood sugar. For example, legumes are difficult to digest and have a low glycemic index; flour is easy to digest, so the food has a high glycemic index. The soluble viscous fiber increases the viscosity of intestinal contents, thus reducing the interaction between starch and digestive enzymes, such as oats and beans, which contain a lot of viscous fiber, are low food glycemic index foods. In addition, the increase of fat and protein can reduce the gastric emptying and the digestion rate of food in the small intestine, so high-fat foods have relatively lower glycemic index than equivalent low-fat foods, but it should be remembered that any type of fatty food should be used within the limit regardless of its high or low food glycemic index.
On the other hand, because insulin response in human body will increase with the increase of carbohydrate intake, blood glucose will not increase indefinitely, and long-term high insulin response will increase the burden on pancreas, which will easily lead to insulin-resistant diabetes. Therefore, when consuming a diet containing high carbohydrates, it is quite important to choose foods with low food glycemic index to reduce insulin secretion.
In addition, acid can slow down the gastric emptying rate of food and prolong the time to enter the small intestine, so it can lower blood sugar. Red currant vinegar is found to be the best among all types of vinegar, while the role of lemon juice cannot be ignored.
Glycemic index of various foods.
1.Low glycemic index food (GI 55 or below)
Grains: whole egg noodles, soba noodles, vermicelli, black rice, black rice porridge, macaroni, lotus root powder
Vegetables: konjac, corn, cabbage, cucumber, celery, eggplant, green pepper, kelp, egg, enoki mushroom, shiitake mushroom, spinach, tomato, bean sprout, asparagus, cauliflower, onion, lettuce.
Beans: S beans, eyebrow beans, chick peas, tofu, bean curd, G beans, lentils, string beans.
Fruits: apples, pears, oranges, peaches, raisins, grapefruits, sorbets, pears, grapefruit, strawberries, cherries, kumquats, grapes.
Milk: milk, low-fat milk, fat milk, low-fat cheese, black tea, yogurt, unsweetened beans {.
Sugar and sugar alcohols: fructose, lactose, xylitol, esomat, maltitol, sorbitol.
2.Medium glycemic index foods (GI 56-69)
Grains: red rice, brown rice, sago, contribute to the D.C. bread, cereals, etc.
Vegetables: sweet potato, taro, potato chips, tomatoes, lotus root, burdock
Meat: fish, chicken, duck, pork, lamb, beef, shrimp, crab, etc.
Beans: h beans, winter flour, cream, condensed milk, fresh milk extract, yogurt, and
Fruits: papaya, raisins, pineapple, bananas, mangoes, cantaloupe, kiwi, willow.
Sugar and sugar alcohols: cane sugar, honey, wine, beer, cola, coffee.
3.Foods with high glycemic index (GI 70 or above)
Grains: white rice, steamed buns, doughnuts, glutinous rice, white bread, oatmeal, ramen, fried rice, popcorn.
Meat: gongbao, fatty sausage, egg dumplings.
Vegetables: mashed potato, pumpkin, h potato.
Fruits: watermelon, lychee, eyes, pineapple, dates.
Sugar and sugar alcohols: glucose, sugar, maltose, soda, orange juice, honey.
The benefits of a low GI diet are many, but you have to control the amount of food before choosing low GI food groups. Don’t think that low GI food has little effect on blood sugar, so you can eat whatever you want. In fact, whether low or high glycemic index food, the carbohydrates in it will directly affect blood sugar, eat too much, the result will also make blood sugar rise quickly. So the first guard t to control blood sugar is to take the right amount of carbohydrates according to your needs. The second guard t, of course, is to choose low GI food, index in 55 or below is low glycemic index food, between 56 to 69 is medium glycemic index food, 70 or above is high glycemic index food. Different foods, although the same amount, but the impact on blood sugar is different, for example, ten grains of raisins contain carbohydrates, equal to an apple, or a bowl of watermelon, but the body is slower to absorb the sugar of raisins and apples, the absorption of watermelon is faster, so although the same amount, but eat low glycemic index of raisins or an apple, better than eating high glycemic index of watermelon.
There are six major factors that affect the glycemic index of food.
1, the more carbohydrates in the food, the higher the glycemic index, especially e is fine u of white bread, white rice, white sugar.
2, the higher the amount of fiber, the lower the glycemic index, so most whole-grain foods and vegetables, are classified as healthy food.
For example, ripe fruits have a higher glycemic index than unripe ones.
4.Foods with lower pH value will have a relatively lower glycemic index.
5.Foods that are diluted, ground or diced are easier to be digested and absorbed, so the glycemic index^ is higher.
6.Foods with higher fat content will have a relatively lower glycemic index.
Although, the low glycemic index diet is about high fiber and low sugar healthy diet, but because only the quality of carbohydrates in food, it is easier to ignore the impact of fat in food on the body, so low glycemic index of high-fat food, over-eating, will also seriously affect weight and cardiovascular health.
Ten principles of healthy diet for diabetics
The principles of eating for diabetic patients are basically the same as those for ordinary healthy people, and these principles include the following.
1, daily food should include cereals, milk, meat, vegetables, etc., recipes often change, rich and varied, to avoid partial food.
2.At least three meals a day, morning, noon and night, each meal should include at least three types of food (cereals, vegetables, meat or milk).
3. Patients who need insulin injections must have a stable diet plan, especially to control the amount of sugar in each meal.
4. To abstain from sweet, salty, oily food and alcohol.
5. Limit foods high in saturated fatty acids and cholesterol, such as sausage, fatty meat, shrine oil, egg yolk, animal offal and shellfish.
6, to abstain from caffeine-based beverages, including coffee, strong tea, soft drinks, fruit juices, etc.
7, to consume fiber-rich foods, such as brown rice, whole wheat bread, squash and vegetables.
8, to avoid eating cured or smoked foods, such as curd, sausage, ham, bacon, lunch meat, etc.
9, to avoid eating many times by the high temperature of the oil cooking food, not to eat moldy peanuts and cereals.
10, to maintain a normal weight, do not overeat; to exercise regularly, so that blood sugar is often maintained within the normal range, in order to reduce the chance of complications.