Human nutrition

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Any study done to determine nutritional status must take into account the state of the body before and after experiments, as well as the chemical composition of the whole diet and of all the materials excreted and eliminated from the body including urine and feces. These latter technologies include pasteurisation , autoclavation , drying , salting , and separation of various components, all of which appearing to alter the original nutritional contents of food. The omega-3 eicosapentaenoic acid EPA , which can be made in the human body from the omega-3 essential fatty acid alpha-linolenic acid ALA , or taken in through marine food sources, serves as a building block for series 3 prostaglandins e. Undernourishment, or hunger, according to the FAO, is dietary intake below the minimum daily energy requirement. Some of the structural material can also be used to generate energy internally, and in either case it is measured in Joules or kilocalories often called "Calories" and written with a capital 'C' to distinguish them from little 'c' calories. There are two subcategories:

National Health and Nutrition Examination Survey

An appropriately balanced intake of omega-3 and omega-6 partly determines the relative production of different prostaglandins: In industrialized societies, people typically consume large amounts of processed vegetable oils, which have reduced amounts of the essential fatty acids along with too much of omega-6 fatty acids relative to omega-3 fatty acids.

Dietary fiber is a carbohydrate , specifically a polysaccharide, which is incompletely absorbed in humans and in some animals. Like all carbohydrates, when it is metabolized, it can produce four Calories kilocalories of energy per gram, but in most circumstances, it accounts for less than that because of its limited absorption and digestibility.

The two subcategories are insoluble and soluble fiber. Insoluble dietary fiber consists mainly of cellulose , a large carbohydrate polymer that is indigestible by humans, because humans do not have the required enzymes to break it down, and the human digestive system does not harbor enough of the types of microbes that can do so.

Soluble dietary fiber comprises a variety of oligosaccharides , waxes , esters , resistant starches, and other carbohydrates that dissolve or gelatinize in water. Many of these soluble fibers can be fermented or partially fermented by microbes in the human digestive system to produce short-chain fatty acids which are absorbed and therefore introduce some caloric content.

Whole grains, beans and other legumes , fruits especially plums , prunes , and figs , and vegetables are good sources of dietary fiber. Fiber is important to digestive health and is thought to reduce the risk of colon cancer. Fiber provides bulk to the intestinal contents, and insoluble fiber especially stimulates peristalsis — the rhythmic muscular contractions of the intestines which move digesta along the digestive tract.

Some soluble fibers produce a solution of high viscosity ; this is essentially a gel, which slows the movement of food through the intestines.

Additionally, fiber, perhaps especially that from whole grains, may help lessen insulin spikes and reduce the risk of type 2 diabetes. Proteins are the basis of many animal body structures e. Each protein molecule is composed of amino acids which contain nitrogen and sometimes sulphur these components are responsible for the distinctive smell of burning protein, such as the keratin in hair.

The body requires amino acids to produce new proteins protein retention and to replace damaged proteins maintenance. Amino acids are soluble in the digestive juices within the small intestine, where they are absorbed into the blood. Once absorbed, they cannot be stored in the body, so they are either metabolized as required or excreted in the urine.

Proteins consist of amino acids in different proportions. The most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition. The synthesis of some amino acids can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress, and those are called conditionally essential.

A vegetarian diet can adequately supply protein, support pregnancy, childhood and athletic endeavors, [15] and lower the risk of cardiovascular disease and cancer.

Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon , hydrogen , nitrogen , and oxygen that are present in nearly all organic molecules.

The term "mineral" is archaic, since the intent is to describe simply the less common elements in the diet. Some are heavier than the four just mentioned — including several metals , which often occur as ions in the body.

Some dietitians recommend that these be supplied from foods in which they occur naturally, or at least as complex compounds, or sometimes even from natural inorganic sources such as calcium carbonate from ground oyster shells. Some are absorbed much more readily in the ionic forms found in such sources. On the other hand, minerals are often artificially added to the diet as supplements; the most well-known is likely iodine in iodized salt which prevents goiter.

Many elements are required in smaller amounts microgram quantities , usually because they play a catalytic role in enzymes. As with the minerals discussed above, some vitamins are recognized as essential nutrients, necessary in the diet for good health. Vitamin D is the exception: Certain vitamin-like compounds that are recommended in the diet, such as carnitine , are thought useful for survival and health, but these are not "essential" dietary nutrients because the human body has some capacity to produce them from other compounds.

Moreover, thousands of different phytochemicals have recently been discovered in food particularly in fresh vegetables , which may have desirable properties including antioxidant activity see below ; experimental demonstration has been suggestive but inconclusive. Other essential nutrients not classed as vitamins include essential amino acids see above , essential fatty acids see above , and the minerals discussed in the preceding section.

Vitamin deficiencies may result in disease conditions: Malnutrition refers to insufficient, excessive, or imbalanced consumption of nutrients. In developed countries, the diseases of malnutrition are most often associated with nutritional imbalances or excessive consumption.

Although there are more people in the world who are malnourished due to excessive consumption, according to the United Nations World Health Organization , the greatest challenge in developing nations today is not starvation, but insufficient nutrition — the lack of nutrients necessary for the growth and maintenance of vital functions. Research indicates that improving the awareness of nutritious meal choices and establishing long-term habits of healthy eating has a positive effect on a cognitive and spatial memory capacity, potentially increasing a student's potential to process and retain academic information.

Some organizations have begun working with teachers, policymakers, and managed foodservice contractors to mandate improved nutritional content and increased nutritional resources in school cafeterias from primary to university level institutions. Health and nutrition have been proven to have close links with overall educational success.

Nutritional supplement treatment may be appropriate for major depression , bipolar disorder , schizophrenia , and obsessive compulsive disorder , the four most common mental disorders in developed countries.

Supplements that have been studied most for mood elevation and stabilization include eicosapentaenoic acid and docosahexaenoic acid each of which are an omega-3 fatty acid contained in fish oil , but not in flaxseed oil , vitamin B 12 , folic acid , and inositol.

Cancer has become common in developing countries. According to a study by the International Agency for Research on Cancer , "In the developing world, cancers of the liver, stomach and esophagus were more common, often linked to consumption of carcinogenic preserved foods, such as smoked or salted food, and parasitic infections that attack organs.

Developed countries "tended to have cancers linked to affluence or a 'Western lifestyle' — cancers of the colon, rectum, breast and prostate — that can be caused by obesity, lack of exercise, diet and age.

The same report recommends eating mostly foods of plant origin and aiming to meet nutritional needs through diet alone, while limiting consumption of energy -dense foods, red meat , alcoholic drinks and salt and avoiding sugary drinks , processed meat and moldy cereals grains or pulses legumes. Protein consumption leads to an increase in IGF-1 , which plays a role in cancer development. Several lines of evidence indicate lifestyle-induced hyperinsulinemia and reduced insulin function i. For example, hyperinsulinemia and insulin resistance are strongly linked to chronic inflammation, which in turn is strongly linked to a variety of adverse developments such as arterial microinjuries and clot formation i.

Evidence indicates that diets possibly protective against metabolic syndrome include low saturated and trans fat intake and foods rich in dietary fiber , such as high consumption of fruits and vegetables and moderate intake of low-fat dairy products.

The challenges facing global nutrition are disease, child malnutrition, obesity, and vitamin deficiency. The most common non-infectious diseases worldwide, that contribute most to the global mortality rate, are cardiovascular diseases, various cancers, diabetes, and chronic respiratory problems, all of which are linked to poor nutrition. Nutrition and diet are closely associated with the leading causes of death, including cardiovascular disease and cancer.

Obesity and high sodium intake can contribute to ischemic heart disease, while consumption of fruits and vegetables can decrease the risk of developing cancer. Foodborne and infectious diseases can result in malnutrition, and malnutrition exacerbates infectious disease.

Poor nutrition leaves children and adults more susceptible to contracting life-threatening diseases such as diarrheal infections and respiratory infections. According to UNICEF, in , million children across the globe were underweight and one in four children, million, were stunted in growth. Childhood malnutrition is common and contributes to the global burden of disease. When humans are undernourished, they no longer maintain normal bodily functions, such as growth, resistance to infection, or have satisfactory performance in school or work.

Many children are born with the inherent disadvantage of low birth weight, often caused by intrauterine growth restriction and poor maternal nutrition, which results in worse growth, development, and health throughout the course of their lifetime.

Data on global and regional food supply shows that consumption rose from in all regions. Diets became more diverse, with a decrease in consumption of cereals and roots and an increase in fruits, vegetables, and meat products.

Undernourishment, or hunger, according to the FAO, is dietary intake below the minimum daily energy requirement. The spike in food prices prevented many people from escaping poverty, because the poor spend a larger proportion of their income on food and farmers are net consumers of food. Malnutrition in industrialized nations is primarily due to excess calories and non-nutritious carbohydrates, which has contributed to the obesity epidemic affecting both developed and some developing nations.

Obesity is more prevalent amongst high income and higher middle income groups than lower divisions of income. Vitamins and minerals are essential to the proper functioning and maintenance of the human body.

There are 20 trace elements and minerals that are essential in small quantities to body function and overall human health. Iron deficiency is the most common inadequate nutrient worldwide, affecting approximately 2 billion people. Vitamin A plays an essential role in developing the immune system in children, therefore, it is considered an essential micronutrient that can greatly affect health.

Estimates say that Moderate deficiencies are common in Europe and Africa, and over consumption is common in the Americas. This ultimately leads to poor school performance and impaired intellectual capabilities. Improvement of breast feeding practices, like early initiation and exclusive breast feeding for the first two years of life, could save the lives of 1. This leaves children less likely to contract diarrheal diseases and respiratory infections.

Besides the quality and frequency of breastfeeding, the nutritional status of mothers affects infant health. When mothers do not receive proper nutrition, it threatens the wellness and potential of their children.

In the US, dietitians are registered RD or licensed LD with the Commission for Dietetic Registration and the American Dietetic Association, and are only able to use the title "dietitian," as described by the business and professions codes of each respective state, when they have met specific educational and experiential prerequisites and passed a national registration or licensure examination, respectively.

In California, registered dietitians must abide by the "Business and Professions Code of Section Archived from the original on Anyone may call themselves a nutritionist, including unqualified dietitians, as this term is unregulated. Some states, such as the State of Florida, have begun to include the title "nutritionist" in state licensure requirements.

Dietary and physical activity guidelines from the USDA are presented in the concept of a plate of food which in superseded the MyPyramid food pyramid that had replaced the Four Food Groups. Department of Health and Human Services provides a sample week-long menu which fulfills the nutritional recommendations of the government.

These disparities are a direct product of social inequalities and social inequalities are rising throughout the industrialized world, particularly in Europe. South Asia has the highest percentage and number of underweight children under five in the world, at approximately 78 million children.

The Eastern and Southern African nations have shown no improvement since in the rate of underweight children under five. Further nutrient indicators show that only 12 per cent of Cambodian babies are exclusively breastfed and only 14 per cent of households consume iodized salt.

This region has undergone the fastest progress in decreasing poor nutrition status of children in the world. Occurring throughout the world, lack of proper nutrition is both a consequence and cause of poverty. According to UNICEF, children in rural locations are more than twice as likely to be underweight as compared to children under five in urban areas.

That likelihood doubles to four times in Peru. In the United States, the incidence of low birthweight is on the rise among all populations, but particularly among minorities. Nutrition directly influences progress towards meeting the Millennium Goals of eradicating hunger and poverty through health and education.

Policy and programming must target both individual behavioral changes and policy approaches to public health. While most nutrition interventions focus on delivery through the health-sector, non-health sector interventions targeting agriculture, water and sanitation, and education are important as well. For example, in , iodine deficiency was particularly prevalent, with one in five households, or 1.

Emergencies and crises often exacerbate undernutrition, due to the aftermath of crises that include food insecurity, poor health resources, unhealthy environments, and poor healthcare practices. Interventions aimed at pregnant women, infants, and children take a behavioral and program-based approach.

Behavioral intervention objectives include promoting proper breast-feeding, the immediate initiation of breastfeeding, and its continuation through 2 years and beyond. However, because supplementation often occurs too late, these programs have had little effect.

For instance, several East Asian nations have enacted legislation to increase iodization of salt to increase household consumption. For example, in the Philippines , improved production and market availability of iodized salt increased household consumption.

Nutrition is taught in schools in many countries. In England and Wales the Personal and Social Education and Food Technology curricula include nutrition, stressing the importance of a balanced diet and teaching how to read nutrition labels on packaging. In many schools a Nutrition class will fall within the Family and Consumer Science or Health departments. In some American schools, students are required to take a certain number of FCS or Health related classes.

Vitamin D is an exception, as it can be synthesized in the skin in the presence of UVB radiation , and many animal species can synthesize vitamin C. Vitamin deficiencies may result in disease conditions, including goitre , scurvy , osteoporosis , impaired immune system, disorders of cell metabolism, certain forms of cancer, symptoms of premature aging, and poor psychological health , among many others. Phytochemicals such as polyphenols are compounds produced naturally in plants phyto means "plant" in Greek.

In general, the term is used to refer to compounds which do not appear to be nutritionally essential and yet may have positive impacts on health. To date, there is no conclusive evidence in humans that polyphenols or other non-nutrient compounds from plants have health benefit effects. While initial studies sought to reveal if nutrient antioxidant supplements might promote health, one meta-analysis concluded that supplementation with vitamins A and E and beta-carotene did not convey any benefits and may in fact increase risk of death.

Vitamin C and selenium supplements did not impact mortality rate. Health effects of non-nutrient phytochemicals such as polyphenols were not assessed in this review. Animal intestines contain a large population of gut flora. In humans, the four dominant phyla are Firmicutes , Bacteroidetes , Actinobacteria , and Proteobacteria. Bacteria in the large intestine perform many important functions for humans, including breaking down and aiding in the absorption of fermentable fiber, stimulating cell growth, repressing the growth of harmful bacteria, training the immune system to respond only to pathogens, producing vitamin B 12 , and defending against some infectious diseases.

There is not yet a scientific consensus as to health benefits accruing from probiotics or prebiotics. Carnivore and herbivore diets are contrasting, with basic nitrogen and carbon proportions vary for their particular foods. Many herbivores rely on bacterial fermentation to create digestible nutrients from indigestible plant cellulose, while obligate carnivores must eat animal meats to obtain certain vitamins or nutrients their bodies cannot otherwise synthesize.

Plant nutrition is the study of the chemical elements that are necessary for plant growth. Some elements are directly involved in plant metabolism. However, this principle does not account for the so-called beneficial elements, whose presence, while not required, has clear positive effects on plant growth. A nutrient that is able to limit plant growth according to Liebig's law of the minimum is considered an essential plant nutrient if the plant cannot complete its full life cycle without it.

There are 16 essential plant soil nutrients, besides the three major elemental nutrients carbon and oxygen that are obtained by photosynthetic plants from carbon dioxide in air, and hydrogen , which is obtained from water. Plants uptake essential elements from the soil through their roots and from the air consisting of mainly nitrogen and oxygen through their leaves.

Green plants obtain their carbohydrate supply from the carbon dioxide in the air by the process of photosynthesis. Carbon and oxygen are absorbed from the air, while other nutrients are absorbed from the soil. These hydrogen ions displace cations attached to negatively charged soil particles so that the cations are available for uptake by the root. In the leaves, stomata open to take in carbon dioxide and expel oxygen. The carbon dioxide molecules are used as the carbon source in photosynthesis.

Although nitrogen is plentiful in the Earth's atmosphere, very few plants can use this directly. Most plants, therefore, require nitrogen compounds to be present in the soil in which they grow. This is made possible by the fact that largely inert atmospheric nitrogen is changed in a nitrogen fixation process to biologically usable forms in the soil by bacteria.

Plant nutrition is a difficult subject to understand completely, partially because of the variation between different plants and even between different species or individuals of a given clone. Elements present at low levels may cause deficiency symptoms, and toxicity is possible at levels that are too high.

Furthermore, deficiency of one element may present as symptoms of toxicity from another element, and vice versa. Canada's Food Guide is an example of a government-run nutrition program.

Produced by Health Canada , the guide advises food quantities, provides education on balanced nutrition, and promotes physical activity in accordance with government-mandated nutrient needs. Like other nutrition programs around the world, Canada's Food Guide divides nutrition into four main food groups: Dietary and physical activity guidelines from the USDA are presented in the concept of MyPlate , which superseded the food pyramid , which replaced the Four Food Groups.

Department of Health and Human Services provides a sample week-long menu that fulfills the nutritional recommendations of the government.

Governmental organisations have been working on nutrition literacy interventions in non-primary health care settings to address the nutrition information problem in the U. The FNP has developed a series of tools to help families participating in the Food Stamp Program stretch their food dollar and form healthful eating habits including nutrition education. It is designed to assist limited-resource audiences in acquiring the knowledge, skills, attitudes, and changed behavior necessary for nutritionally sound diets, and to contribute to their personal development and the improvement of the total family diet and nutritional well-being.

Launched in , this program promotes lifelong healthful eating patterns and physically active lifestyles for children and their families. It is an interactive educational program designed to help prevent childhood obesity through classroom activities that teach children healthful eating habits and physical exercise. Nutrition is taught in schools in many countries.

In England and Wales , the Personal and Social Education and Food Technology curricula include nutrition, stressing the importance of a balanced diet and teaching how to read nutrition labels on packaging. In many schools, a Nutrition class will fall within the Family and Consumer Science or Health departments.

In some American schools, students are required to take a certain number of FCS or Health related classes. Nutrition is offered at many schools, and, if it is not a class of its own, nutrition is included in other FCS or Health classes such as: In many Nutrition classes, students learn about the food groups, the food pyramid, Daily Recommended Allowances, calories, vitamins, minerals, malnutrition, physical activity, healthful food choices, portion sizes, and how to live a healthy life.

In the US, Registered dietitian nutritionists RDs or RDNs [89] are health professionals qualified to provide safe, evidence-based dietary advice which includes a review of what is eaten, a thorough review of nutritional health, and a personalized nutritional treatment plan. They also provide preventive and therapeutic programs at work places, schools and similar institutions.

Certified Clinical Nutritionists or CCNs, are trained health professionals who also offer dietary advice on the role of nutrition in chronic disease, including possible prevention or remediation by addressing nutritional deficiencies before resorting to drugs. These Board Certified Nutritionists typically specialize in obesity and chronic disease.

In order to become board certified, potential CNS candidate must pass an examination, much like Registered Dieticians. This exam covers specific domains within the health sphere including; Clinical Intervention and Human Health. The study found that health literacy increases with education and people living below the level of poverty have lower health literacy than those above it. Another study examining the health and nutrition literacy status of residents of the lower Mississippi Delta found that 52 percent of participants had a high likelihood of limited literacy skills.

For example, only 12 percent of study participants identified the My Pyramid graphic two years after it had been launched by the USDA. The study also found significant relationships between nutrition literacy and income level and nutrition literacy and educational attainment [93] further delineating priorities for the region. Among these problems are the lack of information about food choices, a lack of understanding of nutritional information and its application to individual circumstances, limited or difficult access to healthful foods, and a range of cultural influences and socioeconomic constraints such as low levels of education and high levels of poverty that decrease opportunities for healthful eating and living.

The links between low health literacy and poor health outcomes has been widely documented [94] and there is evidence that some interventions to improve health literacy have produced successful results in the primary care setting. More must be done to further our understanding of nutrition literacy specific interventions in non-primary care settings [93] in order to achieve better health outcomes.

Malnutrition refers to insufficient, excessive, or imbalanced consumption of nutrients by an organism. In developed countries, the diseases of malnutrition are most often associated with nutritional imbalances or excessive consumption. In developing countries, malnutrition is more likely to be caused by poor access to a range of nutritious foods or inadequate knowledge.

The aim was to boost nutrition and livelihoods by producing a product that women could make and sell, and which would be accepted by the local community because of its local heritage.

Although under- and over-nutrition are often viewed as human problems, pet animals can be under- or overfed by their owners, domesticated animals can be undernourished for macro- and micro-nutrients, affecting growth and health, and wild animals can be undernourished to the point of starvation and death.

Nutritionism is the view that excessive reliance on food science and the study of nutrition can lead to poor nutrition and to ill health.

It was originally credited to Gyorgy Scrinis , [96] and was popularized by Michael Pollan. Since nutrients are invisible, policy makers rely on nutrition experts to advise on food choices. Because science has an incomplete understanding of how food affects the human body, Pollan argues, nutritionism can be blamed for many of the health problems relating to diet in the Western World today.

ULs are set a safe fraction below amounts shown to cause health problems. ULs are part of Dietary Reference Intakes. When too much of one or more nutrients is present in the diet to the exclusion of the proper amount of other nutrients, the diet is said to be unbalanced.

High calorie food ingredients such as vegetable oils, sugar and alcohol are referred to as "empty calories" because they displace from the diet foods that also contain protein, vitamins, minerals and fiber. Research indicates that improving the awareness of nutritious meal choices and establishing long-term habits of healthy eating have a positive effect on cognitive and spatial memory capacity, with potential to increase a student's ability to process and retain academic information.

Some organizations have begun working with teachers, policymakers, and managed foodservice contractors to mandate improved nutritional content and increased nutritional resources in school cafeterias from primary to university level institutions. Health and nutrition have been proven to have close links with overall educational success. There is limited research available that directly links a student's Grade Point Average G.

Additional substantive data is needed to prove that overall intellectual health is closely linked to a person's diet, rather than just another correlation fallacy. Nutritional supplement treatment may be appropriate for major depression , bipolar disorder , schizophrenia , and obsessive compulsive disorder , the four most common mental disorders in developed countries. Cancer is now common in developing countries.

According to a study by the International Agency for Research on Cancer , "In the developing world, cancers of the liver, stomach and esophagus were more common, often linked to consumption of carcinogenic preserved foods, such as smoked or salted food, and parasitic infections that attack organs. Several lines of evidence indicate lifestyle-induced hyperinsulinemia and reduced insulin function i.

For example, hyperinsulinemia and insulin resistance are strongly linked to chronic inflammation, which in turn is strongly linked to a variety of adverse developments such as arterial microtrauma and clot formation i. Hyperinsulinemia and insulin resistance the so-called metabolic syndrome are characterized by a combination of abdominal obesity , elevated blood sugar , elevated blood pressure , elevated blood triglycerides , and reduced HDL cholesterol.

The state of obesity clearly contributes to insulin resistance, which in turn can cause type 2 diabetes. Virtually all obese and most type 2 diabetic individuals have marked insulin resistance. Although the association between overweight and insulin resistance is clear, the exact likely multifarious causes of insulin resistance remain less clear. It has been demonstrated that appropriate exercise, more regular food intake, and reducing glycemic load see below all can reverse insulin resistance in overweight individuals and thereby lower their blood sugar level , in those with type 2 diabetes.

In addition, reduced leptin signaling to the brain may reduce leptin's normal effect to maintain an appropriately high metabolic rate.

In any case, analogous to the way modern man-made pollution may possess the potential to overwhelm the environment's ability to maintain homeostasis , the recent explosive introduction of high glycemic index and processed foods into the human diet may possess the potential to overwhelm the body's ability to maintain homeostasis and health as evidenced by the metabolic syndrome epidemic.

Antinutrients are natural or synthetic compounds that interfere with the absorption of nutrients. Nutrition studies focus on antinutrients commonly found in food sources and beverages. The relatively recent increased consumption of sugar has been linked to the rise of some afflictions such as diabetes, obesity, and more recently heart disease.

Increased consumption of sugar has been tied to these three, among others. In the same time span that obesity doubled, diabetes numbers quadrupled in America. Increased weight, especially in the form of belly fat, and high sugar intake are also high risk factors for heart disease.

Elevated amounts of Low-density lipoprotein LDL cholesterol, is the primary factor in heart disease. In order to avoid all the dangers of sugar, moderate consumption is paramount. Since the Industrial Revolution some two hundred years ago, the food processing industry has invented many technologies that both help keep foods fresh longer and alter the fresh state of food as they appear in nature.

Cooling is the primary technology used to maintain freshness, whereas many more technologies have been invented to allow foods to last longer without becoming spoiled.

These latter technologies include pasteurisation , autoclavation , drying , salting , and separation of various components, all of which appearing to alter the original nutritional contents of food. Pasteurisation and autoclavation heating techniques have no doubt improved the safety of many common foods, preventing epidemics of bacterial infection. But some of the new food processing technologies have downfalls as well.

Modern separation techniques such as milling , centrifugation , and pressing have enabled concentration of particular components of food, yielding flour, oils, juices, and so on, and even separate fatty acids, amino acids, vitamins, and minerals. Inevitably, such large-scale concentration changes the nutritional content of food, saving certain nutrients while removing others.

Heating techniques may also reduce food's content of many heat-labile nutrients such as certain vitamins and phytochemicals, and possibly other yet-to-be-discovered substances.

In addition, processed foods often contain potentially harmful substances such as oxidized fats and trans fatty acids. A dramatic example of the effect of food processing on a population's health is the history of epidemics of beri-beri in people subsisting on polished rice. Removing the outer layer of rice by polishing it removes with it the essential vitamin thiamine , causing beri-beri. Another example is the development of scurvy among infants in the late 19th century in the United States.

It turned out that the vast majority of sufferers were being fed milk that had been heat-treated as suggested by Pasteur to control bacterial disease. Pasteurisation was effective against bacteria, but it destroyed the vitamin C.

As mentioned, lifestyle- and obesity-related diseases are becoming increasingly prevalent all around the world. There is little doubt that the increasingly widespread application of some modern food processing technologies has contributed to this development.

The food processing industry is a major part of modern economy, and as such it is influential in political decisions e. In any known profit-driven economy, health considerations are hardly a priority; effective production of cheap foods with a long shelf-life is more the trend.

In general, whole, fresh foods have a relatively short shelf-life and are less profitable to produce and sell than are more processed foods. Thus, the consumer is left with the choice between more expensive, but nutritionally superior, whole, fresh foods, and cheap, usually nutritionally inferior, processed foods.

Because processed foods are often cheaper, more convenient in both purchasing, storage, and preparation , and more available, the consumption of nutritionally inferior foods has been increasing throughout the world along with many nutrition-related health complications. From Wikipedia, the free encyclopedia. This article is about Nutrition in general. For Nutrition in humans, see Human nutrition.

For Nutrition in animals, see Animal nutrition. For nutrition in plants, see Plant nutrition. For the medical journal, see Nutrition journal. Mineral nutrient and Composition of the human body. List of antioxidants in food.

Animal nutrition and Human nutrition. Nutrition portal Food portal. Food Balance Wheel Biology: Bioenergetics Digestion Enzyme Dangers of poor nutrition Deficiency Avitaminosis is a deficiency of vitamins. Boron deficiency medicine Chromium deficiency Iron deficiency medicine Iodine deficiency Magnesium deficiency medicine Diabetes Eating disorders Illnesses related to poor nutrition Malnutrition Obesity Childhood obesity Starvation Food: In children, sleep is also vital for growth and development.

Ongoing sleep deprivation has been linked to an increased risk for some chronic health problems. In addition, sleep deprivation has been shown to correlate with both increased susceptibility to illness and slower recovery times from illness.

Health science is the branch of science focused on health. There are two main approaches to health science: The science builds on many sub-fields, including biology , biochemistry , physics , epidemiology , pharmacology , medical sociology.

Applied health sciences endeavor to better understand and improve human health through applications in areas such as health education , biomedical engineering , biotechnology and public health. Organized interventions to improve health based on the principles and procedures developed through the health sciences are provided by practitioners trained in medicine , nursing , nutrition , pharmacy , social work , psychology , occupational therapy , physical therapy and other health care professions.

Clinical practitioners focus mainly on the health of individuals, while public health practitioners consider the overall health of communities and populations. Workplace wellness programs are increasingly adopted by companies for their value in improving the health and well-being of their employees, as are school health services in order to improve the health and well-being of children. Public health has been described as "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals.

The population in question can be as small as a handful of people or as large as all the inhabitants of several continents for instance, in the case of a pandemic. Public health has many sub-fields, but typically includes the interdisciplinary categories of epidemiology , biostatistics and health services.

Environmental health , community health , behavioral health , and occupational health are also important areas of public health. The focus of public health interventions is to prevent and manage diseases, injuries and other health conditions through surveillance of cases and the promotion of healthy behavior , communities , and in aspects relevant to human health environments.

Its aim is to prevent health problems from happening or re-occurring by implementing educational programs , developing policies , administering services and conducting research. Vaccination programs and distribution of condoms to prevent the spread of communicable diseases are examples of common preventive public health measures, as are educational campaigns to promote vaccination and the use of condoms including overcoming resistance to such.

Public health also takes various actions to limit the health disparities between different areas of the country and, in some cases, the continent or world. One issue is the access of individuals and communities to health care in terms of financial, geographical or socio-cultural constraints to accessing and using services. The great positive impact of public health programs is widely acknowledged.

Due in part to the policies and actions developed through public health, the 20th century registered a decrease in the mortality rates for infants and children and a continual increase in life expectancy in most parts of the world. For example, it is estimated that life expectancy has increased for Americans by thirty years since , [54] and worldwide by six years since Personal health depends partially on the active, passive, and assisted cues people observe and adopt about their own health.

These include personal actions for preventing or minimizing the effects of a disease, usually a chronic condition, through integrative care. They also include personal hygiene practices to prevent infection and illness, such as bathing and washing hands with soap; brushing and flossing teeth ; storing, preparing and handling food safely ; and many others.

Personal health also depends partially on the social structure of a person's life. The maintenance of strong social relationships , volunteering , and other social activities have been linked to positive mental health and also increased longevity.

One American study among seniors over age 70, found that frequent volunteering was associated with reduced risk of dying compared with older persons who did not volunteer, regardless of physical health status. Prolonged psychological stress may negatively impact health, and has been cited as a factor in cognitive impairment with aging, depressive illness, and expression of disease.

Relaxation techniques are physical methods used to relieve stress. Psychological methods include cognitive therapy , meditation , and positive thinking , which work by reducing response to stress. Improving relevant skills, such as problem solving and time management skills, reduces uncertainty and builds confidence, which also reduces the reaction to stress-causing situations where those skills are applicable.

In addition to safety risks, many jobs also present risks of disease, illness and other long-term health problems. Among the most common occupational diseases are various forms of pneumoconiosis , including silicosis and coal worker's pneumoconiosis black lung disease. Asthma is another respiratory illness that many workers are vulnerable to.

Workers may also be vulnerable to skin diseases, including eczema , dermatitis , urticaria , sunburn , and skin cancer. As the number of service sector jobs has risen in developed countries, more and more jobs have become sedentary , presenting a different array of health problems than those associated with manufacturing and the primary sector.

Contemporary problems, such as the growing rate of obesity and issues relating to stress and overwork in many countries, have further complicated the interaction between work and health. Many governments view occupational health as a social challenge and have formed public organizations to ensure the health and safety of workers.

Examples of these include the British Health and Safety Executive and in the United States , the National Institute for Occupational Safety and Health , which conducts research on occupational health and safety, and the Occupational Safety and Health Administration , which handles regulation and policy relating to worker safety and health.

From Wikipedia, the free encyclopedia. This article is about the human condition. For other uses, see Health disambiguation. Social determinants of health and Risk factor. This section has an unclear citation style. The references used may be made clearer with a different or consistent style of citation and footnoting. March Learn how and when to remove this template message. Healthy diet and Human nutrition.

Sleep and Sleep deprivation. Health science and Health care. Chronic care management , Social relation , and Stress management. Occupational safety and health. In Grad, Frank P. Bulletin of the World Health Organization. How should health be defined?

The Hastings Center Studies. Journal of Community Health. The first ten years of the World Health Organization. Regional Office for Europe C; Scherer, H; Robinson, W.

Understanding the user's perspective". Journal of Public Health Management and Practice.