|
| Essential Nutrients |
必需营养素 |
| Balanced and reasonable diet and nutrition are the basis of human health. The essential nutrients in body can be grouped into 6 categories: proteins, fats, carbohydrates and trace elements, vitamins, minerals and water. These nutrients are digested in gastrointestinal tract and absorbed into the body to ensure the normal growth and development of body and physiological functions. Balanced diet and nutrients not only prevent diseases, but also contribute to the diagnosis and treatment of diseases and promotion of health. |
均衡、合理的饮食与营养是人类健康的根本。人体需要的必需营养素可分成六大类：蛋白质、脂肪、碳水化合物与微量元素、维生素，矿物质和水。这些营养素在胃肠道消化吸收并进入人体，保证机体的正常生长发育和各种生理功能。均衡的饮食与营养不仅可以预防疾病，还可帮助诊断和治疗疾病、促进康复。 |
A. Carbohydrates
Carbohydrates are the chief source of energy, containing carbon, hydrogen, and oxygen. It functions physically to provide energy, maintain regular activities of the heart and neurologic systems, protect liver from toxification and prevent ketosis. |
A. 碳水化合物
碳水化合物是能量的主要来源，含有碳、氢、和氧等物质。其重要生理功能为供给热能、维持心脏和神经系统的正常活动、保肝解毒、预防酮病。 |
| Carbohydrates include sugars, starches, and cellulose. Simple sugars such as fruit sugar are easily digested. Starches are more complex and require more sophisticated enzyme processes to be reduced to glucose. Glucose is converted sugar or starch and appears in the body as blood sugar. Some glucose is processed by the liver, converted to glycogen, and stored by the liver for later use. |
碳水化合物包括糖、淀粉和纤维素。单糖，如水果糖，易于消化；淀粉较为复杂，它通过酶解还原为葡萄糖；葡萄糖是糖或淀粉的转化物，在机体内则为血糖。有些葡萄糖经肝脏处理转化为肝糖并得以贮存备用。 |
| Too many carbohydrates are unhealthy since they crowd out other important foods and prevent the body from receiving the necessary nutrients for healthy maintenance. Too few carbohydrates are also unhealthy. It leads to loss of energy, depression and ketosis as well as a breakdown of body protein. |
过多的碳水化合物有害健康，它排挤了其它一些重要食物，阻止机体接受维持健康所需的其他必需营养素；碳水化合物过少也不利健康，它会导致能量丢失、抑郁和酮毒症，而且会导致体内蛋白质的分解。 |
The amount and kind of carbohydrates consumed for optional health are determined by the following factors:
1. Differences of body structure
2. Expenditure of energy
3. Basal metabolism
4. General health status |
决定健康所需的碳水化合物摄入数量及种类的因素有下列几个：
1. 身体结构差异
2. 能量消耗
3. 基础代谢率
4. 健康状况 |
B. Fats
Fats or lipids are the second important nutrients next to carbohydrates. Fatty acids are the basic components of fat and can mainly be grouped into two: saturated fatty acids usually from animal sources and unsaturated fatty acids primarily from vegetables, nuts, or seed sources. |
B. 脂肪
脂肪又叫脂质，它仅次于碳水化合物的第二大营养素。脂肪酸是脂肪的基本成份，它可以分成两大类：来源于动物的饱和脂肪酸和来源于植物、坚果或种子的不饱和脂肪酸。 |
| Fats function to provide energy, assist in building tissue cells, provide essential fatty acids, maintain body temperature, protect viscera, and act as carriers for the fat-soluble vitamins A, D, E, and K, promoting absorption and utilization of these vitamins. |
脂肪的作用为：提供热能、参与构成组织细胞、供给必需脂肪酸、维持人体体温、保护脏器、充当脂溶性维生素A、D、E和K的载体，促进其吸收和利用。 |
| Too much fat leads to weight problems. It also causes poor metabolism of food products because the digestive and absorption processes are affected. Too little fat leads to skin problems and unhealthy blood and arteries. |
脂肪过多可导致体重问题，同时通过影响机体的消化吸收过程而影响食物代谢。脂肪不足会导致皮肤、血液、动脉等方面疾病。 |
C. Proteins
Proteins are complex organic compounds. They are digested and broken down to form 22 amino acids. Proteins are critical to all aspects of growth and development of body tissues and necessary for the building of muscles, blood, skin, internal organs, hormones, and enzymes. Protein is also a sources of energy. When there is insufficient carbohydrate or fat in the body, protein is burned to provide energy. |
C. 蛋白质
蛋白质属于复合有机物，经消化分解，蛋白质可以生产出22种氨基酸。蛋白质对机体组织的生长发育至关重要，也是构建肌肉、血液、皮肤、内脏、激素和酶的必需物质。蛋白质也是热能来源，当体内碳水化合物或脂肪不足时，就会通过燃烧蛋白质来获取热能。 |
| There are eight amino acids that can’t be produced by the body. They must be obtained from the diet. The food in which all eight are present is called a complete protein, otherwise an incomplete protein. Most meat and dairy products are complete proteins while most vegetables and fruits incomplete proteins. |
有八种氨基酸是无法由体内生成的。他们必须由饮食获取。如果某食物含有全部八种氨基酸，则这种食物就被称为全蛋白质食物。否则即为非全蛋白食物。多数肉类和乳制品为全蛋白食物，多数植物及水果类食物为非全蛋白质食物。 |
| Protein deficiency can affect the entire body – organs, tissues, skin, and muscles, as well as certain body processes. |
蛋白质不足可影响整个机体――器官、组织、皮肤、肌肉及某些机体过程。 |
D. Vitamins
Vitamins are found only in living things. They usually cannot be synthesized by the human body. Vitamins can be grouped according to the substance in which they are soluble: fat-soluble and water-soluble. Vitamins A, D, E, and E are all fat-soluble while B-complex vitamins, vitamin C and the bioflavonoids water-soluble. Vitamins have no caloric value, but they are as necessary to the body as any other basic nutrients. |
D. 维生素
维生素只存在于生命物体，通常不能由人体合成。按维生素的溶解环境，维生素可以分为两大类：脂溶性和水溶性。维生素A、D、E和K为脂溶性维生素，B族维生素及维生素C和生物素属于水溶维生素。维生素不提供热量，但机体的重要性并不亚于其它基本营养素。 |
| Vitamins have different sources and functions. Vitamin A, for example, may come from fish oil, animal livers, egg yolk, butters, green and yellow vegetables. Vitamins function as photoreceptor mechanism of retina, maintenance of integrity of epithelia, lysosome stability, glycoprotein synthesis. |
维生素的来源及作用各不相同。如维生素A，它的来源包括鱼肝油、肝脏、蛋黄、奶油、绿叶菜、黄色蔬菜等。它的作用有：视网膜光受体机制、维护上皮细胞的完整性、溶酶体的稳定性、糖蛋白的合成等。 |
| Neither excess nor insufficient vitamins are healthy to body. Too few proteins lead to night blindness, perifollicular hyperkeratosis, xerophthalmia, keratomolacia, increased morbidity and mortality in young children. Toxicity includes headache, peeling of skin, hepatosplenomegaly, and bone thichening. |
维生素不足或过多都对机体害。维生素不足可导致夜盲、毛囊周角化过度、异物笥眼炎、儿童发病率我死亡率增高等。维生素毒性作用包括头痛、脱皮、肝脾肿大、骨磳厚等。 |
E. Water
Water is not specifically a nutrient. But it is essential for survival. Water is involved in every body process from digestion and absorption to excretion. It is a major portion of circulation and is the transporter of nutrients throughout the body. |
E. 水
水并不是营养素，但水对生存必不可少。水参与了机体从消化吸收到排泄的全过程，是体内循环的重要组成部分和体内营养素的运送者。 |
| Body water performs three major functions: gives form to the body, comprising from 50 – 75 percent of the body mass; provides the necessary environment for cell metabolism; and maintains a stable body temperature. |
水的作用主要有三个：给机体以形，机体的50－70%含有水；为细胞代谢提供了必要的环境；保持体温的稳定。 |
F. Minerals
Minerals form 60 –90 percent of all inorganic material in the body. They are found in bones, teeth, soft tissue, muscle, blood, and nerve cells and essential for metabolic processes. Minerals are grouped according to the amount found in the body: major minerals and trace minerals. The former includes sodium, potassium, calcium, magnesium, phosphorous and chlorine, all of which have a known function in the body. The latter includes iron, iodine, zinc, manganese, and copper. Their function in the body remains unclear. |
F. 矿物质
矿物质占体内无机材料的60－90%，骨、齿、软组织、肌肉、血液、及神经细胞中都有矿物质，它是代谢过程的重要元素。根据体内数量，矿物质可分为两类：常量矿物质和微量元数。前者如钠、钾、钙、镁、磷和氯等，其在机体内的作用从所共知；后者如铁，碘、锌、锰和铜等，对人体的作用尚不明了。 |
| Minerals act on organs and in metabolic processes. They serve as catalysts for many reactions such as controlling muscle responses, maintaining the nervous systems, and regulating acid-base balance. They assist in transmitting messages, maintaining cardiac stability, and regulating metabolism and absorption of other nutrients. A deficiency will lead to severe illnesses. Iron, for example, is a component of hemoglobin, myoglobin, and many enzymes in the body. Iron deficiency is the most common nutritional deficiency in the world. It leads to anemia. Excessive minerals can throw the body out of balance. Excess iron can cause vomiting, diarrhea, and damage to the intestine. |
矿物质对器官及在机体代谢过程中发挥作用。它是多种反应的催化剂，如控制肌肉反应、维持神经系统功能、调节酸碱平衡等。它协助信息传递、维持心脏稳定、调节其他营养素的代谢和吸收。矿物质不足会导致严重疾病，如铁是体内血红蛋白、肌红蛋白和许多酶的成分。缺铁引起贫血，这是世界上最为常见的营养缺乏症。过多的矿物质也会使机体失去平衡。如过量的铁可引起呕吐、腹泻、肠损害等。 |
|
