What is sugar?

Sugar in nutrition is not what we generally think of as a sweet substance, but another name for most carbohydrates. According to FAO/ WHO standards, sugars can be divided into three types according to their molecular size and whether they can be hydrolyzed: monosaccharide, disaccharide and polysaccharide, and all kinds of sugars are interconnected to form oligosaccharides and polysaccharides. Glucose, sucrose (white sugar), fructose and lactose are our most common sweet sugars. However, sugar is not limited to this, but also includes starchy foods in the form of polysaccharides, such as rice, noodles, potatoes, sweet potatoes and corn. Polysaccharide can be hydrolyzed and decomposed into monosaccharide glucose by salivary amylase after entering the mouth, such as the sweetness of steamed bread after repeated chewing. Sugar is the common name of sugar water compounds, and carbohydrate is the chemical definition of sugar.

Why is it called carbohydrate? How does sugar provide energy for our bodies?

Because in the molecular structure of sugar, the ratio of hydrogen to oxygen is 2: 1 (both water molecules are 2: 1), and there is excess carbon, it is called carbohydrate. In the structure of life, sugar does not participate in the construction of structures or cells. Its only function is as the most direct, efficient and cheapest energy substance. No matter what sugar we absorb, it will eventually break down into glucose and enter the body (only fructose reaches the liver directly). After reaching the body, it will be transported to all cells in the body with our blood, and then with the help of insulin, it will enter the cells to combine with oxygen, and then burn in the cell processing factory of mitochondria, so that each cell will generate heat energy. For critically ill or emergency patients, the hospital will inject glucose intravenously for the first time. The principle is to send glucose into the blood in the most efficient way through infusion, and then send it to every cell through blood circulation. Within the 6 trillion cells of the human body, there are their own energy processing plants-mitochondria. Mitochondria use glucose and oxygen to synthesize ATP (energy) needed by cells, and at the same time produce metabolic waste carbon dioxide and water.

Sugar has a wide range of sources, and almost exists in more than 80% of daily food. It is almost impossible for the human body to lack sugar. Some people will question what is hypoglycemia? In fact, on the contrary, hypoglycemia is caused by frequent intake of foods that are easy to cause blood sugar fluctuations, resulting in more insulin secretion by the pancreas. The high concentration of insulin in blood is the direct cause of hypoglycemia. The source of sugar also determines that it is easy for modern people to eat too much sugar. The fate of sugar in the body includes four directions. Firstly, cells take glucose and convert it into ATP for cells to use; The second is the temporary storage of glycogen in synthetic glycogen muscle; Third, excess glucose will be converted into fat and stored under the skin or internal organs; Fourth, excess sugar will be converted into other saccharides (plaque garbage in blood and organs). It can be seen that excessive sugar, the body has no ability to decompose and excrete in time, bringing great health risks.

It is almost impossible for the body to lack carbohydrates. On the one hand, almost all foods contain carbohydrates to some extent. On the other hand, the source of glucose in the body can be directly decomposed by glycogen in liver and muscle besides intestinal absorption. Even if the glycogen in liver glycogen can't meet the energy demand, the body will decompose protein and fat to generate glucose for energy supply through the physiological mechanism of gluconeogenesis.

It's not that carbohydrates are useless, because they are cheap and easy to digest and absorb, and because they provide energy very efficiently and quickly. They are a very important part of our diet. However, the key point is that carbohydrates are also good or bad. For example, although apples are sweet, they are rich in water and dietary fiber. After entering the intestine, it is not easy to be absorbed by the intestine, which determines that apples will not cause large fluctuations in blood sugar concentration, while sugar is the opposite. According to the ability to cause blood sugar to rise, sugar food is divided into a new concept called GI blood sugar index, which means that after this carbohydrate enters the human body, it will cause. Foods with a GI value higher than 70 include white bread, white rice, noodles, steamed bread, sugar, syrup, cakes, donuts and so on. In other words, in order to avoid the risk of excessive sugar in daily life, these foods should not be eaten in excess.

In addition, from the perspective of human evolution, in the evolution of 3 million years, human beings mainly used nomadic hunting and fishing as production methods. Until 6.5438 million years ago, mankind entered the era of agricultural civilization and began to grow rice and corn, and cultivated several kinds of food artificially. That is to say, in the 3 million years of human evolution, carbohydrates began to become an important part of diet until the recent 1 10,000 years. In the previous 2.99 million calendar years, most of the human diet was meat, and only in a few short months when the fruits and vegetables ripened every year could we eat rich sugar. From the perspective of genetic evolution, human genes are not suitable for too much sugar in the diet. Because of this, excessive sugar is also the chief culprit of many chronic diseases.

Although carbohydrates are a very important nutrient for human survival, the health risks caused by excessive carbohydrates are gradually increasing around the world, and the low-carbon (low-sugar) diet structure will be the mainstream of health in the future. As a very important nutrient for our human survival, how can we reasonably ingest sugar?

1. Back to our normal diet: the nutrition of five cereals.

Starting from two aspects, the first is the sugar itself, such as cola drinks, ice cream, fruit tea, etc., which has a high sugar content, and the other is refined refined rice flour, which will soon become sugar after eating, and the excess sugar will become fat, causing hidden dangers of diabetes. We should give priority to miscellaneous grains. The sugar in coarse grains is wrapped in crude fiber and is releasing sugar bit by bit. The released sugar enters cells to participate in cell metabolism and energy supply, so it will not become fat accumulation in the body.

2. Cut off the food whose blood sugar rises immediately.

Eat less and eat more.

4. Eat foods that slowly release sugar.