The food glycemic index is the ability of a food to cause a rise in blood glucose in the human body, because the glycemic index is derived from human tests, and most methods of evaluating food are chemical methods. Therefore, we also often say that the food glycemic index is a physiological parameter. High GI food, after entering the gastrointestinal digestion, has a high absorption rate, glucose is released quickly, and the peak of glucose entering the blood is high, that is, the blood sugar rises high; low GI food, after staying in the gastrointestinal for a long time, has a low absorption rate, glucose is released slowly, and the peak of glucose entering the blood is low and falls slowly, which simply means that the blood sugar is lower. Factors affecting GI Theoretically, there are many factors affecting GI, mainly the following: 1, the type of carbohydrates in food. Simply put, monosaccharides are directly absorbed and have a higher GI value than polysaccharides. Branched-chain starch is digested faster than straight-chain starch and has a higher GI value. 2, the impact of the content of other components in food. Other components in food such as fat and protein content can slow down the absorption rate of food, thus reducing the GI, but it should be noted that an increase in the proportion of fat can increase calorie intake and increase the risk of atherosclerosis, and an increase in the proportion of protein increases the burden on the kidneys, so the proportion should be limited. Increase the content of dietary fiber in food is not only beneficial to reduce GI, but also improve intestinal flora and other effects. 3, the shape and characteristics of food. Larger particles of food need to be chewed and mechanical grinding of the stomach over, prolonging the time of digestion and absorption, the glycemic response is slow and mild form. 4. The processing and cooking method of food. Different processing and cooking processes and methods can affect the digestibility of food. Generally speaking, the finer the processing of food, the more easily absorbed, the greater the role of glycemic. 5, in addition, the cooking method is also very important, the longer the cooking time of the same raw materials, the higher the GI of the food. The longer the cooking time of the same raw material, the higher the GI of the food. When we cook the food, the porridge is highly burnt, the chewing and mechanical grinding process of the mouth and stomach is short, and the digestion and absorption time is also short, so the blood sugar rises rapidly, but the function of the pancreas in diabetic patients cannot rapidly secrete a large amount of insulin to counteract the rising blood sugar, which leads to the insulin and blood sugar rising out of sync, and the direct result leads to postprandial hyperglycemia and possible hypoglycemia before the next meal. Hypoglycemia.