What does nutrition mean to human health?
Seven things: "firewood, rice, oil, salt, sauce, vinegar and tea" show that people can't live without the word "eat" every day. Moreover, everyone needs to "eat" to maintain the whole process of life from birth to old age. Therefore, nutrition means the construction of life.
Human beings have the most basic needs for food and nutrition: (1) to provide heat, maintain body temperature, and meet the needs of physiological activities, work and life. (2) Construct human tissues, supply materials needed for growth, development, tissue synthesis and decomposition, and create conditions for making body fluids, hormones, immune antibodies, etc. (3) Keep the functions of various organs of the human body running well, and the work among all parts can be coordinated.
Through long-term practice and exploration, people realize that the nutritional function of food is realized through its nutritional components, which are called nutrients. There are nearly 50 kinds of essential nutrients needed by human beings: they are usually divided into seven categories, namely: protein, fat, carbohydrates (also known as sugars), vitamins, inorganic salts (also known as minerals, including macroelements and trace elements with contents less than 50 parts per million of human body weight), water and dietary fiber. It has been found that no natural food can meet all kinds of nutrients needed by human body, and no single kind of nutrients can have comprehensive nutritional functions. For example, the nutrition of milk and eggs can be described as "rich", but the lack of iron in milk and vitamin C in eggs will inevitably lead to "fly in the ointment"; Fat is a high-calorie diet, and each gram of fat can provide 37.6 kilojoules of calories. However, excessive intake of dietary fat is positively correlated with the incidence of coronary heart disease, atherosclerosis and hyperlipidemia. Therefore, eating only one kind of food, no matter how high its nutritional value, can not meet the needs of human function, let alone maintain human health.
In order to ensure physical fitness and improve the efficacy of various organizations, we must ensure that we eat a variety of foods and "eat" scientifically and reasonably. That is: the heat should be sufficient, but it should not be excessive; The types of nutrients are complete and the proportion is appropriate; Eat regularly, don't be hungry and have a full meal, and don't overeat and overeat. Be on time and in moderation.
The key to scientific and reasonable nutrition lies in "comprehensiveness", "balance" and "moderation". Because of malnutrition (lack or excess), the consequences are hidden, slow and serious. Such as nutritional deficiency, can cause edema, anemia, night blindness and a series of diseases; Overnutrition can lead to modern civilized diseases, such as cardiovascular and cerebrovascular diseases, diabetes, obesity and even cancer, which also affect people's quality of life and longevity.
How to eat is scientific and reasonable.
(1) Food varieties should be diversified. Three meals a day should be carefully arranged. The more kinds of food you eat every day, the better, preferably above 15, and the variety of nutrients should be as complete as possible. Because the more kinds of food, the less prone to the problem of nutritional imbalance, and the supply of various trace elements can also be guaranteed.
(2) You can't eat whatever you want. In recent years, the atmosphere of nutrition in diet has become stronger and stronger. However, there are still many people who believe that "what I want to eat proves what my body needs", and there is no restriction on eating, and I just go my own way. This is very one-sided and unscientific. Because people's appetite only expresses the body's need for nutrients to a certain extent. When life is hard and food and clothing are rare, the human body instinctively likes to eat high-protein and high-fat foods such as big fish and big meat. But today, when our life is rich and big fish and big meat and even delicacies have become daily food, vitamins and minerals are most easily lacking, but our bodies are not good at feeling the profits and losses of these nutrients and rarely respond to the excess of calories and cholesterol. As a result, relying solely on appetite and the old habit of "eating whatever you want" will easily lead to nutritional imbalance, especially cardiovascular and cerebrovascular diseases, diabetes, obesity and other "modern civilization diseases."
(3) Food collocation should be appropriate. Because the intake of more than two kinds of food sometimes leads to an excess of a certain nutrient; there are also two kinds of food intake at the same time that will hinder the absorption and utilization of a certain nutrient. Therefore, when choosing foods, we should take into account the relationship between them, and we must not cook them in one pot indiscriminately. Otherwise, because the food collocation is unreasonable, it will also cause the imbalance of nutrients.
(4) The proportion of three meals a day should be appropriate. In terms of calorie intake, breakfast accounts for about 30%, lunch accounts for about 40% and dinner accounts for about 30%. Generally speaking, we should eat well for breakfast, eat enough for Chinese food and eat less for dinner. It is harmful to health to skip breakfast or dinner and be full.
(5) Food must be safe and hygienic, cooked reasonably, and can arouse appetite. The selected grains, fruits, vegetables or fish should be of good quality. Stale or spoiled foods are easy to be infected with germs, even if cooked at high temperature, it is difficult to kill them, and eating them will make people sick. In cooking, you should also add less sugar and salt, eat less animal fat and eat less fried and roasted food. The daily amount of salt should be controlled within10g.
There is still a lot of knowledge about "eating". But for healthy adults, as long as they pay attention to food diversification and not partial eclipse, they can meet their nutritional needs. As for the developing children or the frail old people, as long as there are no special diseases, paying attention to the variety of food choices and cooking methods on the basis of ensuring appetite can generally ensure good health, and there is no need to supplement health food.
Acid-base balance of food and human health
The so-called good nutrition does not always mean eating big fish and meat, nor eating delicacies all the time, but means reasonable nutrition. Reasonable nutrition is to achieve several balances: the balance of seven nutrients; The balance between animal food and plant food, the balance of three meals a day; The balance between acidic food and alkaline food. Here we focus on the balance between acidic and alkaline foods.
Some of the foods we eat from the outside world every day are acidic and some are alkaline. The acid-base property of food does not refer to the concept of taste, not by taste, but to the concept of physiology, that is, the properties of metabolites produced in the process of metabolism in human body, some of which are acidic and some are alkaline.
The pH value contained in human body is expressed by pH value. Nutrition experts say that the pH value in a healthy human body is between 7.35 and 7.45, that is, the pH of human body fluids is constant-weakly alkaline, so as to maintain normal physiological functions and substance metabolism. Acid-base balance is a necessary condition to protect human health. When the pH value is higher than 7.45, it is called alkalosis. Below 7.35, it is called acidosis.
According to the investigation, with the improvement of people's living standards, many people are acidic due to the increase of eating meat, eggs, fish, animal fat and vegetable oil, and the pH value of body fluids often hovers around 7.35 or slightly lower, so their bodies are in a sub-healthy state between health and disease.
Compared with alkaline constitution, people with acidic constitution often feel weak, memory loss, inattention, backache, diarrhea or constipation, but they can't find anything wrong when they go to the hospital for examination. Being in an acidic physical environment for a long time will lead to calcium deficiency, blood color deepening and viscosity increasing. Women's skin will dim and age prematurely; Children will have symptoms such as dysplasia, loss of appetite and difficulty in concentration; Middle-aged and elderly people are prone to nerve pain, increased blood pressure, arteriosclerosis, gastric ulcer, neurasthenia, constipation, osteoporosis, diabetes, hyperlipidemia and other phenomena. 85% of cancer patients are acidic.
Since most of us are acidic, if we want to adjust our own pH, we should pay attention to strengthening conditioning. In addition to exercising more muscles, adjusting psychology, living regularly, and staying away from bad habits such as smoking and alcohol addiction, the most important thing is to pay attention to scientific nutrition and make the diet structure reasonable. In other words, if you want to keep your blood weakly alkaline, you should think more about food collocation. All foods have acidic and alkaline chemical reactions. Specifically, the meat, eggs, fish, animal fats, vegetable oils and carbohydrates we eat are acidic in the body after digestion and decomposition, especially in body fluids and blood, which can accelerate human arteriosclerosis. And all kinds of coarse grains, vegetables and fruits are mostly alkaline. In order to prevent eating too much acidic food, we should eat more beans, potatoes, milk, vegetables, fruits and other foods to maintain the acid-base balance in the body.
In our body, a lot of proteins, fats and carbohydrates are often decomposed, and the source of acid generally exceeds the source of alkali. Therefore, in terms of acid-base balance, too much acid is often the main aspect of contradiction. Therefore, we must pay attention to the intake of alkaline food in our daily dietary choices, so as to maintain the acid-base balance and ensure our health.
References:
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Author: Xu Yan
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