What does nutrition mean to human health?
The 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 same basic needs for food and nutrition: (1) 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 body: 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 is found that no natural food can meet all kinds of nutrients needed by human body, and no single nutrient 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 dietary fat intake 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 keep human health.
In order to ensure physical fitness and improve the efficacy of various organizations, we must ensure to eat a variety of foods and "eat" scientifically and reasonably. Namely: the heat should be sufficient, but not excessive; The types of nutrients are complete and the proportion is appropriate; Eat regularly, don't have a full meal on an empty stomach, and don't overeat. 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 will lead to modern civilized diseases, such as cardiovascular and cerebrovascular diseases, diabetes, obesity and even cancer, and also affect people's quality of life and longevity.
How to eat is scientific and reasonable.
(1) Food types should be diversified. Three meals a day should be carefully arranged. The more kinds of food you eat every day, the better, preferably 15 or more, and the more complete kinds of nutrients, the better. Because the more kinds of food, the less likely it is to have the problem of unbalanced nutrition, 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 nutritional diet has become stronger and stronger. But there are still many people who believe that "what I want to eat proves what my body needs". There are no restrictions on eating, so I just go my own way. This is very one-sided and unscientific. Because people's appetite only expresses the body's demand for nutrition to a certain extent. When life is hard and food and clothing are carefree, the human body instinctively likes to eat high-protein and high-fat foods such as big fish and big meat. However, in today's affluent life, when big fish, big meat and even delicacies become daily food, vitamins and minerals are most easily lacking, while our bodies are not good at feeling the profit and loss of these nutrients and rarely respond to excess calories and cholesterol. As a result, relying solely on appetite and the old habit of "eating whatever you want" can easily lead to nutritional imbalance, especially "modern civilized diseases" such as cardiovascular and cerebrovascular diseases, diabetes and obesity.
(3) Food collocation should be appropriate. Because the intake of more than two kinds of food sometimes leads to an excess of certain nutrients; There are two kinds of food intake at the same time will hinder the absorption and utilization of certain nutrients. Therefore, when choosing food, we should consider the relationship between them, and never cook a pot indiscriminately. Otherwise, because the food mix is unreasonable, it will also cause nutritional imbalance.
(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, you should eat well for breakfast, eat enough for Chinese food and eat less for dinner. Skipping breakfast or dinner, being full is harmful to your health.
(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 food is easy to be infected with germs, even if it is cooked at high temperature, it is difficult to kill, and eating it will make people sick. In cooking, we should also add less sugar and salt, eat less animal fat and eat less fried and baked food. The daily salt content should be controlled within 10g.
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 the nutritional needs. As for developing children or frail old people, as long as there is no special disease, paying attention to the diversification of food selection 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 always eating delicacies, but refers to 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 outside every day are acidic and some are alkaline. The acidity and alkalinity of food does not refer to the concept of taste, not by taste, but to the concept of physiology, that is, the nature of metabolites produced in the process of human metabolism, 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 value of human body fluids is constant-weakly alkaline 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 survey, with the improvement of people's living standards, many people become 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-health 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. Long-term exposure to acidic physical environment will lead to calcium deficiency, blood color deepening and viscosity increasing. Women's skin will be dull and premature aging; Children will have symptoms such as dysplasia, loss of appetite, and difficulty in concentration; Middle-aged and elderly people are prone to nerve pain, elevated 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 pH, we should pay attention to strengthening conditioning. In addition to exercising more muscles, adjusting psychology and life rules, and staying away from bad habits such as alcohol and tobacco addiction, the most important thing is to pay attention to scientific nutrition and reasonable diet structure. 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 after digestion and decomposition in the body, especially in body fluids and blood, which will accelerate human arteriosclerosis. And all kinds of coarse grains, vegetables and fruits are mostly alkaline. In order to prevent eating too much acidic food, 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 protein, fat and carbohydrate are often decomposed, and the source of acid generally exceeds that 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 diet choice to maintain the acid-base balance and ensure good health.
References:
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Author: Yan Xu
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