What are carbohydrates? What food contains this?

Foods rich in carbohydrates include rice, corn, wheat and other kinds of food as well as various root crops, such as potatoes, yams, potatoes, beans, fruits, vegetables and sugar.

Carbohydrate is a kind of substance widely existing in nature and one of the main components of food. It consists of three elements: carbon, hydrogen and oxygen. Carbohydrates are also called sugar.

Carbohydrate classification

Carbohydrates are divided into monosaccharides, disaccharides, oligosaccharides and polysaccharides. There are three kinds of glycoconjugates: glycolipid, glycoprotein and proteoglycan.

Physiological functions of carbohydrates

(1) Energy supply: glucose is produced per gram 16 kilojoules (4 kilocalories), and carbohydrates ingested by human body are digested into glucose or other monosaccharides to participate in body metabolism. There is no specific amount of carbohydrates in everyone's diet. Nutrition experts in China believe that the calories generated by carbohydrates should account for 60-65% of the total calories. Usually, the carbohydrate intake is mainly polysaccharide, which is high in staple foods such as rice and noodles. While ingesting carbohydrates, other nutrients such as protein, lipids, vitamins, minerals and dietary fiber can also be obtained. However, the intake of monosaccharides or disaccharides such as sucrose cannot supplement other nutrients except calories.

(2) Composition of cells and tissues: Each cell contains carbohydrates, the content of which is 2%- 10%, mainly in the form of glycolipids, glycoproteins and proteoglycans, which are distributed in meninges, organelle membranes, cytoplasm and intercellular substance.

(3) Save protein: The carbohydrate in food is insufficient, so the body has to use protein to meet the energy required for physical activities, which will affect the body's use of protein to synthesize new protein and tissue regeneration. Therefore, it is totally inappropriate to eat meat instead of staple food, because there are few carbohydrates in meat, so that body tissues will use protein to generate heat, which is not good for health. Therefore, the minimum carbohydrate intake of dieters or diabetics should not be lower than 150g staple food.

(4) Maintaining the normal function of brain cells: Glucose is an essential nutrient to maintain the normal function of the brain. When the blood sugar concentration drops, brain tissue can damage the function of brain cells due to lack of energy, leading to dysfunction, dizziness, palpitation, cold sweat and even coma.

(5) Others: Glycoproteins and proteoglycans in carbohydrates have lubricating effects. In addition, it can control the permeability of meninges. It is the precursor of some synthetic biomacromolecules, such as purine, pyrimidine and cholesterol.