MALNUTRITION

Millions of persons in the poor countries of the world cannot afford food that provides adequate amounts of protein and calories. As  result, they suffer from chronic deficiency diseases, especially kwashiorkor, which results from a diet deficient primarily in protein; marasmus, which results from a diet deficient primarily in calories; and protein-calorie malnutrition (PCM), which results from a deficiency of both protein and calories. PCM is more common than either kwashiorkor or marasmus.

营养不良

在世界上贫困家中的数百万人都无法买得起足够数量的蛋白质和热量食物。因此，他们患上了慢性缺乏症疾病，尤其是恶性营养不良病，这主要是饮食缺乏蛋白质造成的；消瘦，主要是在饮食中缺乏热量；而蛋白质-热量营养不良（PCM），是由于既缺乏蛋白质，也缺乏热量。蛋白质-热量营养不良比恶性营养不良或消瘦更常见。

Mild to moderate PCM is more common than severe forms. Chronic mild to moderate PCM in children results in diminished growth and maturation. It increases susceptibility to infection and may also contribute to mental retardation.

轻度至中度蛋白质-热量营养不良比严重的形式更常见。儿童中的慢性轻度至中度蛋白质-热量营养不良会导致发育和成熟降低。它增加了感染易感性，并可能导致智力迟钝。

Marasmus, also known as non-edematous PCM, is found most often in children. The typical marasmic child is emaciated and small for his age. In extreme marasmus the child is almost literally skin and bones.

消瘦，也被称为非水肿的蛋白质-热量营养不良，在儿童中最为常见。典型的消瘦儿童就其年龄来说是瘦弱和矮小的。极端时，消瘦的儿童几乎皮包骨头。

A protein-deficient child with kwashiorkor, also called edematous PCM, may be almost normal in height, with normal or increased body fat, but his body tissues are flabby and swollen with watery (edematous) fluid.

患有恶性营养不良，也被称为水肿性蛋白质-热量营养不良的蛋白质缺乏儿童可能身高几乎是正常的，包括身体脂肪正常或有所增加，但其身体组织是松弛的，而且伴有水样（水肿的）液体的肿胀。

Persons with PCM may also have deficiencies of vitamins and minerals. They are prone to diarrhea and various infections, which in their weakened condition frequently lead to death.

患有蛋白质-热量营养不良的人也可能缺乏维生素和矿物质。他们都易于腹泻和各种感染，在他们虚弱的情况下经常会导致死亡。

PCM is rare in the United States and other developed countries, but it is common in many poor countries of Asia, Africa, and South and Central America. For example, in Central America in the mid-1960’s it was estimated that more than half the children under age five had some degree of growth retardation attributable to malnutrition, and early 3% of the children suffered from severe malnutrition. PCM is a major cause of high infant and childhood death rates. In some poor countries one third or more of the children die before they are five years old.

在美国和其它发达国家，蛋白质-热量营养不良是罕见的，但在亚洲、非洲和中、南美洲的许多贫困国家很常见。例如，在20世纪60年代的中美洲，估计有超过一半，年龄在五岁以下的儿童由于营养不良患有某种程度的生长迟缓，而3%的儿童患有严重的营养不良。蛋白质-热量营养不良是婴儿和儿童死亡率高的一个主要原因。在一些贫困国家，三分之一或更多的儿童不到5岁就死亡了。

Children are especially likely to have PCM because of the additional nutritional needs imposed by growth. In many poor areas the malnutrition of mothers and the trend away from breast feeding further undermine the nutrition of infants. Frequently, mild nutritional deficiencies are made severe by acute illness—most often infectious diarrhea—that interfere with proper absorption of nutrients by the body.

由于生长所强制的额外营养需要，儿童尤其可能患上蛋白质-热量营养不良。在许多穷困地区，母亲的营养不良和远离母乳喂养的趋势会进一步削弱婴儿的营养。通常，轻度的营养缺乏会因急性疾病而变得严重---最常见的是感染性腹泻---会干扰身体对营养物的适当吸收。

See also Food—The World Food Supply

也可参阅食物—世界食物供应词条

 

DISEASES OF OVERNUTRITION

Obesity.  When food calories absorbed by the body exceed those expended, the excess is stored in the body as fat. If the net excess of calories is large, obesity soon results, and obesity promotes high blood pressure, diabetes, and other illnesses. According to data compiled by life insurance companies, more than 25% of American adults over age 30 are obese, that is, they are at least 20% over their ideal weight. Contributing factors to this high incidence of obesity include the relatively low cost of rich, high-calorie food in the United States and the relatively low levels of physical activity typical of American adults.

营养过剩的疾病

过度肥胖。当身体吸收的食物热量超过了那些消耗的热量时，超过的热量就会作为脂肪储存在身体内。如果热量的净过量很大，就会很快过度肥胖，而过度肥胖会导致高血压、糖尿病和其它疾病。根据人寿保险公司编辑的数据，有超过25%的30岁以上的美国成年人肥胖，换句话说，他们至少超过了他们理想体重的20%。导致这种肥胖高发率的因素包括美国富裕相对的低成本、高热量食物以及典型的美国成年人相对较低的体育锻炼水平。

A few individuals may have an innate predisposition to obesity, but in almost all cases obesity results simply from taking in more calories in the form of food and drink than are expended in physical activity.

少数人可能先天就有肥胖的倾向，但在几乎所有的情况中，肥胖仅仅是从食物和饮料中摄入了更多的热量超过了体育锻炼消耗的热量。

Relatively small excesses in calorie intake can result in substantial weight gain. For practical dietary purposes 3,500 calories is equivalent to 1 pound (0.45 kg) of body fat. Thus, if a person’s level of physical activity remains the same, a mere 100 extra calories a day will, on the average, result in a 10 pound weight gain every 35 days (1 kg every 75 days) or more than 10 pounds (4.5 kg) a year. One hundred calories is roughly the amount of energy in a lightly buttered slice of bread or in a large orange, apple, or banana.

摄入相对较少的多余热量也会导致体重大幅增加。就实际的饮食目的来说，3500卡热量相当于1镑（0.45 公斤）的身体脂肪。因此，如果一个人的体育锻炼水平保持不变，平均每天只多摄入100卡热量就会导致每35天增加10镑（每75天1公斤）或1年超过10镑（4.5公斤）。100卡热量大约是在一片面包上涂上的少许黄油，或一只大橙子、苹果，或香蕉所含的能量。

Dieting has become a way of life for many Americans. Each year new fad diets are published and old ones are rediscovered. Although these diet may help many persons lose weight, the majority gain it back within six months or a year. Many dieters do not understand that maintaining one’s ideal weight is the real problem, not losing weight. If the dieter returns to his or her previous pattern of eating and exercise after attaining a desired weight, the previous daily excess of calories is reestablished and the lost weight is inevitably regained. See also DIET; OBESITY.

对于许多美国人来说，饮食已成为了一种生活方式。每年都会发布新的流行饮食和重新发掘过去的饮食。尽管这些饮食会帮助许多人减轻体重，但大多数人在6个月或1年内又会反弹。许多节食者并不明白，保持人的理想体重才是真正的问题，而不是减轻体重。如果节食者在获得了理想的体重后又回到了他或她以前的饮食和锻炼模式，那么先前每天多余的超热量又会恢复，而且减轻的体重会不可避免地反弹。也可参阅节食；肥胖词条。

Nutrition and Heart Disease.  A large body of circumstantial evidence has implicated over-nutrition as one important contributor to the early development of atherosclerotic heart disease. In particular, the evidence suggests that heart attack rates can be reduced if persons eat less saturated fat and less cholesterol. In practice, this would mean a shift from the typical American diet, heavily based on beef and pork, to a diet more oriented to poultry, fish, vegetables, and cereal grains.

营养与心脏病。大量的间接证据表明，营养过剩是一种动脉粥样硬化心脏病早期发展的重要促成因素。尤其是，该证据表明如果人少吃饱和脂肪和少吃胆固醇就能降低心脏病的发作率。实际上，这意味着要从典型的主要以牛肉和猪肉为主的美国饮食转变成以家禽、鱼、蔬菜和谷物为主的一种饮食。

The circumstantial evidence favoring the dietary approach to preventing heart disease includes a sharp drop in deaths from heart disease during famine periods; a correlation between heart-disease rates and intakes of saturated fat and cholesterol; increases in heart-disease rates among immigrants from Oriental to Western countries, probably associated with a change toward typical Western diets high in cholesterol and saturated fats; the finding of cholesterol as  major part of the arterial-wall deposits characteristic of atherosclerosis; the fact that the level of cholesterol in the blood can be lowered by prescribing a diet low in cholesterol and saturated fat; and the experimental production of atherosclerosis in monkeys fed American-style diets high in cholesterol and saturated fat.

有利于预防心脏病饮食方法的间接证据包括，在饥荒期间死于心脏病的人数急剧下降；心脏病发病率与摄入饱和脂肪与胆固醇之间的相互关系；在从东方国家向西方国家移民中心脏病发病率的增加，可能与向典型的高胆固醇和饱和脂肪的西方饮食的转变有关；发现胆固醇是动脉粥样硬化特征动脉壁沉积的主要部分；实际上，血液中胆固醇的水平可以通过规定的低胆固醇和低饱和脂肪饮食来降低；以及给猴子喂食富含胆固醇和饱和脂肪的美式饮食的动脉粥样硬化实验。

In addition, there have been several direct experiments on human populations in which persons who switched to a low-cholesterol, low-saturated-fat diet for several years developed less heart disease than did persons remaining on typical American diets. Unfortunately, the direct studies consisted of only a few hundred people, and the experimental design was not perfect, so the effectiveness of the diet change was not conclusively proved. Nevertheless, most physicians and nutritionist feel that low-cholesterol, low-saturated-fat diets are prudent for most Americans, since blood cholesterol levels of Americans tend to be relatively high. Presently, the average blood cholesterol level and the hear-disease death rate in the United States are among the highest in the world.

另外，有一些对人群的直接实验，其中几年来换成低胆固醇，低饱和脂肪饮食的人们相比依然保持典型美国饮食的人们患心脏病的人数要更少。遗憾的是，直接研究只由几百人组成，而实验设计也不完善，因此饮食变化的效果并未得到确定性的证实。尽管如此，大多数医生和营养专家认为低胆固醇，低饱和脂肪饮食对大多数美国人来说是明智的，因为美国人的血液胆固醇水平相对较高。目前，美国的平均血液胆固醇水平和心脏病死亡率在世界上是最高的。

In the typical American diet the largest source of saturated fat is usually meat and dairy fat. Cholesterol is found most in egg yolk and meat. In practice, therefore, a low-cholesterol, low-saturated-fat diet is one that keeps meat intake to not more than THREE 3-ounce (85-grams) portions week, substituting chicken, fish, or vegetable protein sources; using skim milk and margarine instead of whole milk and butter fat; and eating no more than THREE egg yolks a week. Egg whites need not be restricted.

在典型的美国饮食中饱和脂肪最大的来源通常是肉类和奶制品脂肪。胆固醇主要存在于蛋黄和肉类中。因此，实际上低胆固醇，低饱和脂肪是一种肉类摄入量不超过每周三份3盎司（85克）的饮食，代以鸡、鱼，或蔬菜蛋白质来源；使用脱脂牛奶和人造黄油代替全脂牛奶和奶油脂肪；以及一周食用不超过3个蛋黄。蛋白不需要受限制。

Of course, diet is only one of several important risk factors in premature heart disease. Other major factors are cigarette smoking, high blood pressure, and diabetes mellitus. See also ATHEROSCLEROSIS.

当然，饮食只是早发性心脏病的几个重要原因之一。其它主要原因有吸烟，高血压，以及糖尿病。也可参阅动脉粥样硬化词条。

Dental Caries.  Health teeth and gums depend upon good overall nutrition, including adequate amounts of calcium and vitamins A, D, and C. Cavities, or caries, result from the fermentation of certain food substances, primarily carbohydrates, by bacteria that are present in the mouth. The carbohydrate mainly responsible for tooth decay in the United States is sucrose, simple table sugar, which is present in nearly all candies, pastries, ice creams, and non-dietary soft drinks. The cavity-inducing effect seems to be greatest with sticky foods such as candy, which end to adhere to the teeth. Also, sweets eaten between meals cause more cavities than those eaten with meals—presumably because they are more likely to stick to the teeth when eaten alone.

龋齿。健康牙齿和牙龈取决于良好的整体营养，包括适量的钙和维生素A，D和C。蛀牙和龋齿是由某些食物的发酵造成的，主要是碳水化合物，由口腔中的细菌引发的。在美国，导致蛀牙的主要碳水化合物是普通食糖的蔗糖，它几乎存在于所有的糖果、甜点、冰淇淋和非饮食的软饮料中。诸如糖果这种粘性食物对导致牙齿龋洞的影响似乎最大，它最终都会粘在牙齿上。还有，在两餐之间吃甜食比那些随餐吃甜食的会导致更多的蛀牙---大概是因为单独吃时，它们更有可能粘在牙齿上。

A study of 3,000 Eskimos in Greenland found that only 5% of those living in an isolated native settlement and eating a native diet had tooth decay, while early 50% of those living near a trading station, who consumed European-style food, had tooth decay. See also TEETH.

一项对格陵兰岛的3000名爱斯基摩人的研究发现，那些生活在遥远的土著聚居地，吃当地食物的人中只有5%的人患有蛀牙，而那些早先生活在贸易站附近，消费欧式食物的人中有50%的人患有蛀牙。

VEGETARIANISM

Vegetarian diets vary in the degree to which animal products are avoided. The least restrictive diets are those of the lacto-ovo-vegetarians, who do not eat animal flesh, but do eat eggs and dairy products. Because egg white and some dairy products are outstanding protein sources and fair sources of vitamin B12, the lacto-ovo-vegetarian diet can easily be a nutritionally excellent one. If eggs are omitted but dairy products retained, the task of maintaining a nutritional balance takes greater attention but is not difficult for persons willing to train themselves in the fundamentals of nutrition.

素食主义

素食者的饮食在避免动物产品的程度方面各不相同。最少限制性的饮食是那些乳蛋素食者，他们不吃动物的肉，但吃鸡蛋和奶制品。因为，蛋白和一些奶制品是优质的蛋白质来源和相当好的维生素B12的来源，乳蛋素食者的饮食在营养上很容易成为一种优良的饮食。如果漏掉了鸡蛋，而保留了奶制品，维持营养平衡的任务就需要更多关注，但这对愿意在营养基础方面训练他们自身的人来说并不难。

A nutritionally good pure vegetarian (vegan) diet is much more demanding, and its planning requires superior knowledge of practical nutrition, mainly because of the difficulty of obtaining enough high-quality protein and enough vitamin B12. With few exceptions the protein quality and content of vegetables are low. Thus protein sources must be matched carefully so that the amino-acid deficiencies of one food are compensated by the amino-acid surpluses of other foods. (In addition to amino-acid balance, other factors—some poorly understood—affect the absorption and utilization of proteins.) Since vitamin B12 occurs only in animal products, so far as is now known, strict vegans should probably take a vitamin B12 supplement. Most other vitamins and minerals can be provided in reasonable amounts by a carefully chosen vegan diet.

营养良好的纯素食者的（严格素食者）饮食要求很高，其计划需要对实用的营养有更高的知识，主要是因为很难获得足够的高质量蛋白质和足够的维生素B12。除极少的例外，蔬菜的蛋白质质量和数量都很低。因此，蛋白质来源必须仔细搭配，以便一种食物缺乏的氨基酸被另一种食物剩余的氨基酸所补偿。（除了氨基酸平衡以外，其它因素---一些理解不足---会影响蛋白质的吸收和利用）。由于维生素B12只存在于动物产品中，就目前所知，严格素食者大概会服用维生素B12补充剂。大多数其它的维生素和矿物质可通过仔细选择的严格素食者饮食提供合理的数量。

There is little margin for error in a vegan diet. For this reason it would be dangerous to waste any major part of daily calorie intake on empty calories such as soda, candy, cake, or other foods of meager nutritional value. Unbalanced vegetarian diets such as the all-cereal high-grade Zen macrobiotic diet can result and have resulted in scurvy, anemia, protein starvation, and death. See also VEGETARIANISM.

严格素食者的饮食极少有犯错的余地。由于这个原因，将每天摄入的大部分热量浪费在空热量上，诸如苏打水、糖果、蛋糕或其它少有营养价值的食物上是很危险的。非均衡的素食饮食，比如全谷类高级禅宗长寿饮食可能导致并已经导致了坏血病、贫血、蛋白质匮乏和死亡。也可参阅素食主义词条。

CONROVERSIES IN NUTRITION

Megavitamin Therapy.  Megavitamin therapy uses massive doses of vitamins—10, 50, or more times the RDA---to treat a variety of diseases, including schizophrenia, the common cold, and heart disease. In megavitamin therapy, vitamins are used as medicines or drugs rather than as ordinary nutritional supplements.

对营养的争议

大量维生素疗法。大量维生素疗法使用大剂量的维生素—10倍，50倍，或多倍推荐的日摄入量---来治疗各种疾病，包括精神分裂症、普通感冒和心脏病。在大量维生素疗法中，维生素被用作药物或药品，而不是作为普通的营养补充剂。

Mega-doses of vitamins may be helpful in certain situations. For example, large doses of vitamin B6 have been used successfully to treat certain rare anemias and seizure disorders. On the other hand, in the case of vitamin C for treatment of the common cold, several careful scientific studies have yielded conflicting results. In many other instances, advocates of megavitamin therapy have relied largely on anecdotal evidence, often without adequate allowance for the natural variation in the course of disease or for the sometimes powerful placebo effect. For the most part, neither advocate nor opponents have done carefully designed studies that would prove or disprove benefit from megavitamin therapy.

大剂量的维生素在某些情况下可能有用。例如，大剂量的维生素B6已被成功地用于治疗某些罕见的贫血和癫痫病。另一方面，在用维生素C治疗普通感冒的情况下，几项仔细的科学研究产生了矛盾的结果。在许多其它的例子中，大量维生素疗法提倡者主要依靠一种非正式的证据，通常没有充分考虑到疾病过程的自然变化，或者有时是强大安慰剂的效果。在大多数情况下，提倡者也好，反对者也罢都没有仔细地做过设计研究，来证明或反驳大量维生素疗法的好处。

Food Additives.  The most common as well as the most important use of chemical food additives is to prevent or reduce spoilage of foods. For this reason, a variety of chemical agents that retard oxidation, inhibit bacteria, or prevent fungi from growing are added to foods. Additives are also widely used to give food a more desirable color or flavor.

食品添加剂。最常见和最重要的使用化学食品添加剂是为预防或降低食物的损坏。因此，延缓氧化、抑制细菌，或预防真菌生长的各种各样的化学制剂被加入食品中。添加剂还被广泛地用于赋予食物更令人向往的颜色或风味。

Food additives become a matter for controversy because of the difficulty of judging the relative importance of their intended benefits and their unwanted side effects, of which the one of greatest concern is cancer. Among the most controversial of the additives are the now-banned Red Dye No. 2, a food coloring widely used to give an attractive appearance to processed foods; sodium nitrite, a color fixative and preservative used in hot dogs and other sausages and cold meats; and the artificial sweeteners cyclamate and saccharin, which were the mainstay of the diet soft-drink industry until they were banned by the Food and Drug Administration (FDA). The FDA’s action was compelled by the Delaney Amendment to the Food, Drug, and cosmetic Act. This amendment requires of it—no matter how large or over how long a period of time—can be shown to cause cancer in test animals. See also FOOD ADDITIVVE.

食品添加剂成为了一个有争议的问题，因为很难判断它们预期的好处和它们有害副作用的相对重要性，其中最令人担心的一个问题就是癌症。在有争议的添加剂中是现在已被禁止的2号红色素，一种广泛用于使加工的食品具有吸引人外观的食品色素；亚硝酸纳，一种用于热狗、其它香肠和冷肉的定色剂和防腐剂；以及人造甜味素和糖精，它们是饮食软饮料行业的支柱，直到被美国食品和药品管理局禁止。美国食品和药品管理局的行动是受《食品，药物以及化妆品法案》德莱尼修正案所迫。该修正案要求---无论规模多大或持续多长时间---添加剂都会在实验的动物中导致癌症。也可参阅食品添加剂词条。

Organically Grown Foods.  The terms “organic” and “natural” are often applied to additive-free foods obtained from plants grown without the use of artificial fertilizers or pesticides.

有机种植的食品。“有机的”和“自然的”这两个术语通常用于从没有使用人工肥料或农药的种植植物中获得的无添加剂食品。

People in the organic food movement maintain that organically grown foods are superior in flavor and nutritional quality to “non-organically” grown foods, and that non-organically grown foods may be hazardous to health because of residues of pesticides applied when they were being grown.

有机食品运动中的人们认为，有机种植的食品在风味和营养质量方面都要优于“非有机的”种植食品，而且非有机种植的食品可能对健康有害，因为它们在生长时残留了农药。

In contrast, most food scientists believe that there is no significant nutritional or flavor difference between organic and inorganic foods, and that the pesticide hazard is insignificant when pesticides are applied according to government-specified application schedules and the food are properly washed.

相比之下，大多数食品科学家认为，在有机食品和无机食品之间没有显著的营养或风味上的差别，而且如果是按政府规定的实施时间表使用农药，并且食品清洗得当，那么农药的风险是微不足道的。

Under the present structure of the food industry, organically grown food is considerably more expensive than ordinary food, and it is hard to be sure that the food one eats is truly “organic” except to grow it oneself.

在目前的食品工业结构下，有机种植的食品要比普通食品贵得多，除非他自己种植，否则很难确定一个人吃的食品是真正的“有机食品”。

 

RICHARD N. PODELL, M. D., M. P. H.

                              Overlook Hospital, Summit, N. J.

                             理查德·N. 波德尔，医学博士，

公共卫生学硕士

                                  眺望医院，SUMMIT新泽西州

 

                                        2023年8月9日译

（译者注：该该部分词条位列《大美百科全书》1985年版，第20卷，第573页至575页）