(2) All kinds of nutrients must meet the needs of children's growth and development, neither too much nor too little.
(3) The ratio between nutrients should be appropriate. For example, the heating ratio of protein, fat and carbohydrate is 1︰2.5︰4, high-quality protein should account for1/2 ~ 2/3 of the total amount of protein, and animal protein accounts for 1/3. The heating ratio of three meals is about 30% for breakfast, 40% for Chinese food, 25% for dinner and 5% ~10% for afternoon snacks.
(4) Food is easy to digest and absorb. Nutritional Status and Problems of College Students
At present, college students are generally malnourished because of high tuition fees, increased other expenses, and bad eating habits, such as skipping breakfast, picky eaters, partial eclipse, and saving a full meal on Sundays. At present, there are four kinds of nutritional deficiency diseases that pose the greatest threat to college students' health, namely, protein-heat malnutrition, vitamin A deficiency, iron deficiency anemia and insufficient calcium intake. According to the survey, the protein intake of college students is only 65.5% ~ 74.8% of the standard supply, and the high-quality protein is only about 15% of the total protein. The nutritional value of diet is not high, the intake of meat, eggs, milk and vegetables is less, and the proportion of various foods is unreasonable. There are also some problems in the allocation of three meals, such as about 70% students don't eat breakfast or eat a little. The incidence of vitamin deficiency was 12.5% for boys and 34.4% for girls. The main manifestations are gingival swelling and bleeding (12% ~18%), hair follicle keratinization, dry skin, cracked tongue, rotten mouth and decreased dark adaptation (16.3%). According to the determination of hemoglobin, the prevalence rate of anemia in male college students is 25.9%, and that in female is 5 1.4%, which indicates that there is a serious shortage of high-quality protein and vitamin C in college students' diet, which affects the absorption and utilization of iron.
The role of reasonable nutrition in promoting college students' health and study
Reasonable nutrition can promote physical development.
Nutrition is the most important material basis for the growth and development of college students. The growth and development of organisms, life activities, mental work and physical work all depend on the substance metabolism in the body. In the process of substance metabolism, the body must constantly ingest a certain amount of food from the outside in order to promote growth and development, enhance physical fitness, increase immune function, prevent diseases, improve work efficiency and exercise ability. Reasonable nutrition means that the body can take in all the nutrients necessary to keep healthy, and the proportion of various nutrients meets the needs of the human body. Lack of nutrients, or unbalanced intake of various nutrients, unreasonable dietary structure, etc., will not only cause growth retardation, but also lead to various acute and chronic malnutrition and various nutritional deficiencies. Therefore, reasonable nutrition and dietary balance can better promote the healthy growth of college students.
Reasonable nutrition can improve memory and learning efficiency.
Reasonable nutrition can improve the activity ability of human brain and enhance people's computing ability, memory ability, judgment ability, action ability and vision. The brain is the most active organ in the human body. Although its weight is only about 2% of the human body, the energy consumed by the brain accounts for 20% of the total energy consumed by the whole body. Therefore, reasonable nutrition plays an important role in brain health care.
The brain's need for sugar The efficiency of college students' intellectual activities depends on whether brain cells can obtain the energy generated by a stable blood sugar supply. Under normal circumstances, the human brain almost completely depends on the oxidation of blood sugar (glucose in blood) to supply energy, and it needs about116 ~145g every day. When the blood sugar supply is insufficient, the oxygen consumption of the brain will drop, and those who are light will feel tired, thinking and memory will be reduced, and those who are serious may have shock.
◆ The brain needs protein. In the process of metabolism, the brain needs a certain amount of protein to update itself. Eating protein food with different contents has different effects on brain activities. Increasing the content of protein in food can enhance the function of cerebral cortex. The active chemicals needed by human intelligence activities, such as acetylcholine, norepinephrine, dopamine, serotonin, etc., are all synthesized by amino acids decomposed by protein. The maturation and metabolism of brain neurons and glial cells also depend on many essential amino acids. Among them, glutamic acid can correct the biochemical defects of brain cells, tyrosine directly participates in the evolution of brain cell functions and the composition of neural circuits, and tryptophan is the precursor of 5- hydroxytryptamine, which can promote the improvement of attention and memory functions.
The brain needs fat. The function of brain cells also needs fatty acids, especially polyunsaturated fatty acids such as linoleic acid, linolenic acid and arachidonic acid. These fatty acids cannot be synthesized by the human body and must be ingested from food. If these fatty acids are lacking, it will not only affect the normal development of the brain, but also hinder other functions. Many foods contain these fatty acids, and the foods with high content include soybean oil, vegetable oil and cold water marine fish oil.
The brain needs vitamins. Various vitamins are indispensable for the normal functioning of the brain, especially B vitamins (thiamine and nicotinic acid) can promote the development of the nervous system, the synthesis of neurotransmitters and enhance memory. Vitamin c and vitamin e can delay the aging of brain cells, while vitamin d can improve the sensitivity of nerve cell response.
"Food is the most important thing for the people". With the development of human civilization today, eating is no longer just out of the instinct of survival, but more to get reasonable nutrition from food, so as to make the body and mind healthier. The nutrients in food are called nutrients. There are nearly 50 kinds of nutrients needed by human body, which are usually divided into seven categories, namely protein, fat, sugar (carbohydrate), vitamins, inorganic salts, water and dietary fiber.
Modern nutrition science research shows that nutrition science is closely related to human health, especially to human life span. Paying attention to scientific food nutrition intake and reasonable physical exercise has become an important part of contemporary life.
I. Nutritional function
(1) Nutrition is the foundation of health, and its physiological functions are mainly manifested in the following aspects:
A reasonable nutritional state is not only beneficial to physical health, but also to mental health, because the balanced supply of various nutrients in the body makes the nerves and endocrine in an excellent state, which can make people feel happy, refreshed and in high spirits, which is beneficial to eliminating people's bad mood, relieving psychological pressure, increasing life interest and nourishing emotions.
(B) Nutrition is conducive to intellectual development.
Modern scientific research shows that the brain is the most complex and energetic organ in the human body. Medical research shows that although the weight of human brain is only 1/50 of human body weight, the amount of blood needed by brain accounts for 1/5 of human body. It shows that the brain has a great demand for various nutrients and oxygen. If the supply of various nutrients in the brain cannot be guaranteed, it will lead to abnormal brain structure and function, mental decline, deterioration of memory and memory reproduction ability, distraction and even mental disorders.
Strengthening the brain and improving intelligence through food actually promotes the growth and development of the brain and exerts its normal physiological functions by ingesting various nutrients in food. Therefore, it is very important to supplement different nutrients by supplying various foods, so that the brain is always in the best state, which is very important for improving and improving people's intelligence.
(3) Balanced nutrition can maintain the vitality of youth.
Most students like to take part in physical exercise, cultural entertainment and various social activities. In order to keep their body and mind happy and full of energy in various activities, they must have adequate nutritional support. If there is insufficient nutrition, they will cause fatigue, emaciation and decreased resistance, which is manifested in pallor, general weakness, mental atrophy, and even illness, and loss of youthful vitality.
(D) Balanced nutrition can maintain a healthy figure.
Boys are tall and strong; Only when girls are well-proportioned and curvy can they fully reflect the health and beauty of youth.
Second, the principle of reasonable intake of nutrition
Due to the general lack of nutrition knowledge among students, their diet is basically blind. Malnutrition and overnutrition are common among students, such as malnutrition, obesity, anorexia, malnutrition caused by long-term vegetarian diet, overeating, and partial eclipse. Therefore, we should understand nutrition, pay attention to balanced diet, and scientifically match food to make the diet more in line with health requirements.
(1) balance principle
Balance refers to the relative balance between various nutrients ingested by people and the physiological needs of the body, and vice versa. One aspect of malnutrition is malnutrition and the other is overnutrition. Therefore, a relative balance should be maintained between human nutritional needs and supplements.
(2) the principle of appropriateness
Appropriateness means that the proportion of various nutrients ingested by people should be reasonable, that is, proper diet collocation should be carried out on a comprehensive and balanced basis. There is a certain proportion between the composition of human elements and the requirements of human body for various nutrients under different conditions. Only reasonable nutrition collocation, especially the reasonable proportion of protein, fat and carbohydrate in calories, can help human body to better absorb and utilize nutrients.
(3) the principle of comprehensiveness
Comprehensive means that people should take in all kinds of nutrients comprehensively and not be partial to food. No natural food can include all kinds of nutrients needed by human body, and no single nutrient can have all nutritional functions. Therefore, no matter how rich the nutrition of a food is, it is impossible to fully meet the needs of human health. Only by ingesting various nutrients contained in various foods can we ensure the health needs of people.
(4) the principle of pertinence
Everyone's genetic factors, physical condition, age, living environment, nutritional status and other conditions are different, therefore, nutrition intake and supplement should be treated differently. When the living and working environment and physiological conditions change, the supply of nutrients should be adjusted appropriately.
In addition, in order to ensure good health, we should arrange meals reasonably with the changes of the four seasons. It's spring now, and it's a climate where winter is cold and it's warm, so the diet should be mild and plain.
In a word, nutrition sustains life, and life lies in exercise. The process of people's understanding of nutrition and exercise is the process of continuous improvement of human health and the process of continuous extension of human life. Because the human body needs reasonable and balanced nutrition, it is essential to master the knowledge of "reasonable nutrition" and "scientific nutrition".
China residents' balanced diet pagoda is designed according to China residents' dietary guidelines and the characteristics of China residents' dietary structure. It transforms the principle of balanced diet into the weight of all kinds of food, which is convenient for everyone to implement in daily life.
Dietary guide
First, the food is diverse, mainly cereals.
Second, eat more vegetables, fruits and potatoes.
Diets rich in vegetables, fruits and potatoes play a very important role in maintaining cardiovascular health, enhancing disease resistance, reducing the risk of dry eye in children and preventing some cancers.
Three, often eat milk, beans or their products.
Milk is rich in high-quality protein and vitamins, with high calcium content and high utilization rate. It is an excellent source of natural calcium. The calcium provided by Chinese residents' diet is generally low, reaching only about half of the recommended supply on average.
Beans are traditional foods in China, which contain a lot of high-quality protein, unsaturated fatty acids, calcium, vitamin B 1, vitamin B2, nicotinic acid and so on.
Four, often eat the right amount of fish, poultry, eggs, lean meat, eat less fat and meat oil.
Animal foods such as fish, poultry, eggs and lean meat are good sources of high-quality protein, fat-soluble vitamins and minerals.
Fat and meat oil are high-energy and high-fat foods. Excessive intake often leads to obesity and is a risk factor for some chronic diseases, so we should eat less.
Five, food intake and physical activity should be balanced, to maintain a suitable weight.
Food intake and physical activity are two main factors to control weight.
● If you eat too much and have insufficient activity, the excess energy will accumulate in the body in the form of fat, that is, you will gain weight and gain weight for a long time.
● If the food intake is insufficient and the amount of labor or exercise is too large, it can cause emaciation due to insufficient energy, resulting in a decline in labor ability.
6. Eat a light and salty diet.
Our residents' salt intake is too high, and the average value is more than twice that recommended by the World Health Organization. Epidemiological investigation shows that sodium intake is positively correlated with the incidence of hypertension, so salt should not be too much.
The World Health Organization recommends that the daily salt consumption per person should not exceed 6 grams.
Seven, such as drinking should be limited.
High-alcohol liquor contains high energy and no other nutrients. Excessive drinking will reduce appetite and food intake, resulting in a variety of nutrient deficiencies, and in severe cases, alcoholic cirrhosis.
Eight, eat clean food, no deterioration.
When shopping for food, you should choose food with good appearance, no dirt, impurities, no discoloration and off-taste, and meet the hygiene standards, and strictly control the disease from mouth to mouth.
Note:
Food sources of calcium (mg Ca/ 100g)
1. Milk and dairy products: milk 120, whole milk powder 1030.
2. Shrimp skin: 2000
3. Kelp: 1 177
4. Soybean: 367
5. Rape: 140
6.sesame sauce: 870