In our daily life, we often hear people with diabetes say that they should not eat any food or eat too much, and that they should control the amount of starchy food in their diet, and so on. In fact, the amount and type of food is only one of the factors in the rise of blood sugar. Here is the issue of “food glycemic index”. The so-called “food glycemic index” refers to the percentage value of the level of blood glucose response in the body caused by 50 grams of carbohydrate food and an equivalent amount of glucose in a certain period of time (generally 2 hours). It reflects the speed and ability of food to raise blood glucose compared with glucose, and is a measure of the postprandial glycemic response induced by food. We set the glycemic index of glucose as 100; foods with glycemic index >70 are foods with high glycemic index, which are quickly digested after entering the stomach and intestines, have high absorption rate and enter the bloodstream rapidly, resulting in high peak blood glucose, but also fall rapidly; foods with glycemic index <55 are foods with low glycemic index, which have long residence time in the stomach and intestines, low absorption rate, low peak after being absorbed into the bloodstream, and fall slowly, resulting in postprandial blood glucose. They have long residence time in the gastrointestinal tract, low absorption rate, low peak after absorption into the blood, slow decline, and cause less postprandial blood sugar reaction. There are two main factors that affect the glycemic index of food. Cooking not only changes the flavor of food, but also changes the glycemic index of food. For example, the more starch is pasted, the more easily it is digested and absorbed, and the higher the glycemic index. The starch in raw food exists in the form of small, tightly bound granules, which are difficult for the body to digest and decompose; when the starch granules swell, break and decompose under the action of water and heat to different degrees, for example, when cooking porridge, the rice grains gradually swell and the porridge soup gradually thickens, that is, the pasteification of starch granules. The longer the porridge is cooked, the more adequate the pasting is, the easier it is to be digested and absorbed and cause a rapid rise in blood sugar, and the higher the glycemic index. Another example is that the smaller the particles of food, the easier it is to be broken down by enzymes, and the higher the glycemic index, which is why refined flour food has a higher glycemic index. Understand this, we can pay attention to: coarse grains do not fine work, vegetables can not cut not cut, try not to cut too much or into puree. The second is the composition of food: the different composition of food will also have an impact on blood sugar. For example, beans contain high straight-chain starch, which is difficult to paste and digest, so the glycemic index is low; rice and flour contain high branched-chain starch, which is easy to paste and digest, so the glycemic index is high; dietary fiber is a natural barrier, which can reduce the digestive rate and make the glycemic index lower. The increased content of protein and fat in food can also reduce the gastric emptying and digestion rate, and the glycemic index is also lower. However, regardless of the index, high-fat foods should be consumed in limited amounts. Therefore, it is advisable to use more oats, beans, leafy and stem vegetables rich in dietary fiber, and increase protein appropriately. In addition, adding some acidic substances such as vinegar or lemon juice to food is also an easy way to lower the glycemic index.