Malnutrition

Malnutrition is a condition that results from eating a diet in which nutrients are not enough or are too much such that it causes health problems. The nutrients involved can include: calories, protein, carbohydrates, vitamins or minerals. It is often used specifically to refer to undernutrition where there is not enough calories, protein or micronutrients; however, it also includes overnutrition. If undernutrition occurs during either pregnancy or before the age of two years of age it may result in permanent problems with physical and mental development. Extreme undernourishment, known as starvation, may have symptoms that include: a short height, thin body, very poor energy levels, and swollen legs and abdomen. People also often get infections and are frequently cold. The symptoms of micronutrient deficiencies depend on the micronutrient that is lacking.

Undernourishment is most often due to not enough high quality food available to eat. This is often related to high food prices and poverty. A lack of breast feeding may contribute, as may a number of infectious diseases such as: gastroenteritis, pneumonia, malaria and measles which increase nutrient requirements. There are two main types of undernutrition: protein-energy malnutrition and dietary deficiencies. Protein-energy malnutrition has two severe forms: marasmus (a lack of protein and calories) and kwashiorkor (a lack of just protein). Common micronutrient deficiencies include: a lack of iron, iodine and vitamin A. During pregnancy, due to increased demand, deficiencies become more common. In some developing countries overnutrition in the form of obesity is beginning to present within the same communities as undernutrition. Other causes of malnutrition include anorexia nervosa and bariatric surgery. In the elderly malnutrition becomes more common due to physical, psychological and social factors.

Efforts to improve nutrition are some of the most effective forms of development aid. Breastfeeding can reduce rates of malnutrition and death in children, and efforts to promote the practice increase rates. In young children providing food in addition to breastmilk between six months and two years improves outcomes. There is also good evidence supporting the supplementation of a number of micronutrients during pregnancy and among young children in the developing world. To get food to people who need it most both delivering food and providing money so that people can buy food within local markets are effective. Simply feeding people at school is insufficient. Management of severe malnutrition within the person's home with ready-to-use therapeutic foods is possible much of the time. In those who have severe malnutrition complicated by other health problems treatment within hospital is recommended. This often involves managing low blood sugar, body temperature, dehydration, and gradual feeding. Routine antibiotics are usually recommended due to the high risk of infection. Long term measures include: improving agricultural practices, reducing poverty, improving sanitation, and the empowerment of women.

There were 925 million undernourished people in the world in 2010, an increase of 80 million since 1990. Another billion people are estimated to have a lack of vitamins and minerals. In 2010 protein-energy malnutrition was estimated to have resulted in 600,000 deaths down from 883,000 deaths in 1990. Other nutritional deficiencies, which include iodine deficiency and iron deficiency anemia, result in another 84,000 deaths. Undernutrition as of 2010 was the cause of 1.4% of all disability adjusted life years. About a third of deaths in children are believed to be due to undernutrition; however, the deaths are rarely labelled as such. In 2010 it was estimated to have contributed to about 1.5 million deaths in women and children though some estimate the number may be greater than 3 million. An additional 165 million children have stunted growth from the disease. Undernutrition is more common in developing countries.

Definition
Malnutrition is caused by eating a diet in which nutrients are not enough or are too much such that it causes health problems. It is a category of diseases that includes undernutrition and overnutrition. Overnutrition can result in obesity and overweight.

Malnutrition; however, is frequently used to mean just undernutrition. Undernutrition is sometimes used as a synonym of protein energy malnutrition. While other include both micronutrient deficiencies and protein energy malnutrition in its definition. It defers from calorie restriction in that calorie restriction may not result in negative health effects. The term hypoalimentation means underfeeding.

Undernutrition encompasses stunting, wasting, and deficiencies of essential vitamins and minerals (collectively referred to as micronutrients). The term hunger, which describes a feeling of discomfort from not eating, has been used to describe undernutrition, especially in reference to food insecurity.

The term "severe malnutrition" or "severe undernutrition" is often used to refer specifically to PEM. PEM is often associated with micronutrient deficiency. Two forms of PEM are kwashiorkor and marasmus, and they commonly coexist.

Kwashiorkor (‘displaced child’) is mainly caused by inadequate protein intake resulting in a low concentration of amino acids. The main symptoms are edema, wasting, liver enlargement, hypoalbuminaemia, steatosis, and possibly depigmentation of skin and hair. Kwashiorkor is identified by swelling of the extremities and belly, which is deceiving of actual nutritional status.

Marasmus (‘to waste away’) is caused by an inadequate intake of protein and energy. The main symptoms are severe wasting, leaving little or no edema, minimal subcutaneous fat, severe muscle wasting, and non-normal serum albumin levels. Marasmus can result from a sustained diet of inadequate energy and protein, and the metabolism adapts to prolong survival. It is traditionally seen in famine, significant food restriction, or more severe cases of anorexia. Conditions are characterized by extreme wasting of the muscles and a gaunt expression.

Gomez
In 1956, Gómez and Galvan studied factors associated with death in a group of malnourished children in a hospital in Mexico City, Mexico and defined categories of malnutrition: first, second, and third degree. The degrees were based on weight below a specified percentage of median weight for age. The risk of death increases with increasing degree of malnutrition. An adaptation of Gomez's original classification is still used today. While it provides a way to compare malnutrition within and between populations, the classification has been criticized for being "arbitrary" and for not considering overweight as a form of malnutrition. Also, height alone may not be the best indicator of malnutrition; children who are born prematurely may be considered short for their age even if they have good nutrition.

Waterlow
John Conrad Waterlow established a new classification for malnutrition. Instead of using just weight for age measurements, the classification established by Waterlow combines weight-for-height (indicating acute episodes of malnutrition) with height-for-age to show the stunting that results from chronic malnutrition. One advantage of the Waterlow classification over the Gomez classification is that weight for height can be examined even if ages are not known.

These classifications of malnutrition are commonly used with some modifications by WHO.

Effects
Malnutrition increases the risk of infection and infectious disease, and moderate malnutrition weakens every part of the immune system. For example, it is a major risk factor in the onset of active tuberculosis. Protein and energy malnutrition and deficiencies of specific micronutrients (including iron, zinc, and vitamins) increase susceptibility to infection. Malnutrition affects HIV transmission by increasing the risk of transmission from mother to child and also increasing replication of the virus. In communities or areas that lack access to safe drinking water, these additional health risks present a critical problem. Lower energy and impaired function of the brain also represent the downward spiral of malnutrition as victims are less able to perform the tasks they need to in order to acquire food, earn an income, or gain an education.

Vitamin-deficiency-related diseases (such as scurvy and rickets).

Hypoglycemia (low blood sugar) can result from a child not eating for 4 to 6 hours. Hypoglycemia should be considered if there is lethargy, limpness, convulsion, or loss of consciousness. If blood sugar can be measured immediately and quickly, perform a finger or heel stick.

Signs
In those with malnutrition some of the signs of dehydration differ. Children; however, may still be interested in drinking, have decreased interactions with the world around them, have decreased urine output, and may be cool to touch.

Mortality
Mortality due to malnutrition accounted for 58 percent of the total mortality in 2006: "In the world, approximately 62 million people, all causes of death combined, die each year. One in twelve people worldwide is malnourished and according to the Save the Children 2012 report, one in four of the world’s children are chronically malnourished. In 2006, more than 36 million died of hunger or diseases due to deficiencies in micronutrients".

According to the World Health Organization, malnutrition is the biggest contributor to child mortality, present in half of all cases. Six million children die of hunger every year. Underweight births and intrauterine growth restrictions cause 2.2 million child deaths a year. Poor or non-existent breastfeeding causes another 1.4 million. Other deficiencies, such as lack of vitamin A or zinc, for example, account for 1 million. Malnutrition in the first two years is irreversible. Malnourished children grow up with worse health and lower education achievement. Their own children tend to be smaller. Malnutrition was previously seen as something that exacerbates the problems of diseases as measles, pneumonia and diarrhea. But malnutrition actually causes diseases and can be fatal in its own right.

Psychological
Malnutrition in the form of iodine deficiency is "the most common preventable cause of mental impairment worldwide." "Even moderate deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation's development. The most visible and severe effects — disabling goiters, cretinism and dwarfism — affect a tiny minority, usually in mountain villages. But 16 percent of the world's people have at least mild goiter, a swollen thyroid gland in the neck."

Protein-calorie malnutrition can cause cognitive impairments. For humans, "critical period varies from the final third of gestation to the first 2 years of life". Iron deficiency anemia in children under two years of age likely affects brain function acutely and probably also chronically. Folate deficiency has been linked to neural tube defects.

Causes
Major causes of malnutrition include poverty and food prices, dietary practices and agricultural productivity, with many individual cases being a mixture of several factors. Clinical malnutrition, such as in cachexia, is a major burden also in developed countries. Various scales of analysis also have to be considered in order to determine the sociopolitical causes of malnutrition. For example, the population of a community may be at risk if the area lacks health-related services, but on a smaller scale certain households or individuals may be at even higher risk due to differences in income levels, access to land, or levels of education.

Diseases
Malnutrition can be a consequence of health issues such as gastroenteritis or chronic illness, especially the HIV/AIDS pandemic. Diarrhea and other infections can cause malnutrition through decreased nutrient absorption, decreased intake of food, increased metabolic requirements, and direct nutrient loss. Parasite infections can also lead to malnutrition.

People may become malnourished due to abnormal nutrient loss (due to diarrhea or chronic illness) or increased energy expenditure (secondary malnutrition)

Dietary practices
A lack of adequate breastfeeding leads to malnutrition in infants and children, associated with the deaths of an estimated one million children annually. Illegal advertising of breast milk substitutes continues three decades after its 1981 prohibition under the WHO International Code of Marketing Breast Milk Substitutes.

Deriving too much of one's diet from a single source, such as eating almost exclusively corn or rice, can cause malnutrition. This may either be from a lack of education about proper nutrition, or from only having access to a single food source.

Overnutrition caused by overeating is also a form of malnutrition. In the United States, more than half of all adults are now overweight — a condition that, like hunger, increases susceptibility to disease and disability, reduces worker productivity, and lowers life expectancy. Overeating is much more common in the United States, where for the majority of people, access to food is not an issue. Many parts of the world have access to a surplus of non-nutritious food, in addition to increased sedentary lifestyles. Yale psychologist Kelly Brownell calls this a "toxic food environment” where fat and sugar laden foods have taken precedent over healthy nutritious foods. Not only does obesity occur in developed countries, problems are also occurring in developing countries in areas where income is on the rise. The issue in these developed countries is choosing the right kind of food. More fast food is consumed per capita in the United States than in any other country. The reason for this mass consumption of fast food is its affordability and accessibility. Often fast food, low in cost and nutrition, is high in calories and heavily promoted. When these eating habits are combined with increasingly urbanized, automated, and more sedentary lifestyles, it becomes clear why weight gain is difficult to avoid. However, overeating is also a problem in countries where hunger and poverty persist. In China, consumption of high-fat foods has increased while consumption of rice and other goods has decreased. Overeating leads to many diseases, such as heart disease and diabetes, that may result in death.

Poverty and food prices


In Bangladesh, poor socioeconomic position was associated with chronic malnutrition since it inhibits purchase of nutritious foods such as milk, meat, poultry, and fruits. As much as food shortages may be a contributing factor to malnutrition in countries with lack of technology, the FAO (Food and Agriculture Organization) has estimated that eighty percent of malnourished children living in the developing world live in countries that produce food surpluses. The economist Amartya Sen observed that, in recent decades, famine has always a problem of food distribution and/or poverty, as there has been sufficient food to feed the whole population of the world. He states that malnutrition and famine were more related to problems of food distribution and purchasing power.

It is argued that commodity speculators are increasing the cost of food. As the real estate bubble in the United States was collapsing, it is said that trillions of dollars moved to invest in food and primary commodities, causing the 2007–2008 food price crisis.

The use of biofuels as a replacement for traditional fuels and raises the price of food. The United Nations special rapporteur on the right to food, Jean Ziegler proposes that agricultural waste, such as corn cobs and banana leaves, rather than crops themselves be used as fuel.

Agricultural productivity
Local food shortages can be caused by a lack of arable land, adverse weather, lower farming skills such as crop rotation, or by a lack of technology or resources needed for the higher yields found in modern agriculture, such as fertilizers, pesticides, irrigation, machinery and storage facilities. As a result of widespread poverty, farmers cannot afford or governments cannot provide the resources necessary to improve local yields. The World Bank and some wealthy donor countries also press nations that depend on aid to cut or eliminate subsidized agricultural inputs such as fertilizer, in the name of free market policies even as the United States and Europe extensively subsidized their own farmers. Many, if not most, farmers cannot afford fertilizer at market prices, leading to low agricultural production and wages and high, unaffordable food prices. Reasons for the unavailability of fertilizer include moves to stop supplying fertilizer on environmental grounds, cited as the obstacle to feeding Africa by the Green Revolution pioneers Norman Borlaug and Keith Rosenberg.

Future threats
There are a number of potential disruptions to global food supply that could cause widespread malnutrition.

Climate change is of importance to food security, with 95 percent of all malnourished peoples living in the relatively stable climate region of the sub-tropics and tropics. According to the latest IPCC reports, temperature increases in these regions are "very likely." Even small changes in temperatures can lead to increased frequency of extreme weather conditions. Many of these have great impact on agricultural production and hence nutrition. For example, the 1998–2001 central Asian drought brought about an 80 percent livestock loss and 50 percent reduction in wheat and barley crops in Iran. Similar figures were present in other nations. An increase in extreme weather such as drought in regions such as Sub-Saharan Africa would have even greater consequences in terms of malnutrition. Even without an increase of extreme weather events, a simple increase in temperature reduces the productivity of many crop species, also decreasing food security in these regions.

Colony collapse disorder is a phenomenon where bees die in large numbers. Since many agricultural crops worldwide are pollinated by bees, this represents a threat to the supply of food.

An epidemic of wheat stem rust caused by race Ug99 is currently spreading across Africa and into Asia and, it is feared, could wipe out more than 80 percent of the world’s wheat crops.

Prevention
The effort to bring modern agricultural techniques found in the West, such as nitrogen fertilizers and pesticides, to Asia, called the Green Revolution, resulted in decreases in malnutrition similar to those seen earlier in Western nations. This was possible because of existing infrastructure and institutions that are in short supply in Africa, such as a system of roads or public seed companies that made seeds available. Investments in agriculture, such as subsidized fertilizers and seeds, increases food harvest and reduces food prices. For example, in the case of Malawi, almost five million of its 13 million people used to need emergency food aid. However, after the government changed policy and subsidies for fertilizer and seed were introduced against World Bank strictures, farmers produced record-breaking corn harvests as production leaped to 3.4 million in 2007 from 1.2 million in 2005, making Malawi a major food exporter. This lowered food prices and increased wages for farm workers. Such investments in agriculture are still needed in other African countries like the Democratic Republic of the Congo. The country has one of the highest prevalence of malnutrition even though it is blessed with great agricultural potential John Ulimwengu explains in his article for D+C. Proponents for investing in agriculture include Jeffrey Sachs, who has championed the idea that wealthy countries should invest in fertilizer and seed for Africa’s farmers.

Breastfeeding education helps. Breastfeeding in the first two years and exclusive breastfeeding in the first six months could save 1.3 million children’s lives. In the longer term, firms are trying to fortify everyday foods with micronutrients that can be sold to consumers such as wheat flour for Beladi bread in Egypt or fish sauce in Vietnam and the iodization of salt.

Restricting population size is a proposed solution. Thomas Malthus argued that population growth could be controlled by natural disasters and voluntary limits through “moral restraint.” Robert Chapman suggests that an intervention through government policies is a necessary ingredient of curtailing global population growth. However, there are many who believe that the world has more than enough resources to sustain its population. Instead, these theorists point to unequal distribution of resources and under- or unutilized arable land as the cause for malnutrition problems. For example, Amartya Sen advocates that, “no matter how a famine is caused, methods of breaking it call for a large supply of food in the public distribution system. This applies not only to organizing rationing and control, but also to undertaking work programmes and other methods of increasing purchasing power for those hit by shifts in exchange entitlements in a general inflationary situation.” One suggested policy framework to resolve access issues is termed food sovereignty, the right of peoples to define their own food, agriculture, livestock, and fisheries systems in contrast to having food largely subjected to international market forces. Food First is one of the primary think tanks working to build support for food sovereignty. Neoliberals advocate for an increasing role of the free market. Another possible long term solution would be to increase access to health facilities to rural parts of the world. These facilities could monitor undernourished children, act as supplemental food distribution centers, and provide education on dietary needs. These types of facilities have already proven very successful in countries such as Peru and Ghana. New technology in agricultural production also has great potential to combat under nutrition. By improving agricultural yields, farmers could reduce poverty by increasing income as well as open up area for diversification of crops for household use. The World Bank itself claims to be part of the solution to malnutrition, asserting that the best way for countries to succeed in breaking the cycle of poverty and malnutrition is to build export-led economies that will give them the financial means to buy foodstuffs on the world market.

Management
In response to child malnutrition, the Bangladeshi government recommends 10 steps for treating severe malnutrition. They are to prevent or treat dehydration, low blood sugar, low body temperature, infection, correct electrolyte imbalances and micronutrient deficiencies, start feeding cautiously, achieve catch-up growth, provide psychological support, and prepare for discharge and follow-up after recovery.

Food
The evidence for benefit of supplementary feeding is poor. This is due to the small amount of research done on this treatment.

Specially formulated foods do however appear useful in those from the developing world with moderate acute malnutrition. In young children with severe acute malnutrition it is unclear if ready-to-use therapeutic food differs from a normal diet. They may have some benefits in humanitarian emergencies as they can be eaten directly from the packet, do not require refrigeration or mixing with clean water, and can be stored for years.

In those who are severely malnourished, feeding too much too quickly can result in refeeding syndrome. This can result regardless of route of feeding and can present itself a couple of days after eating with heart failure, dysrhythmias and confusion that can result in death.

Micronutrients
Treating malnutrition, mostly through fortifying foods with micronutrients (vitamins and minerals), improves lives at a lower cost and shorter time than other forms of aid, according to the World Bank. The Copenhagen Consensus, which look at a variety of development proposals, ranked micronutrient supplements as number one.

In those with diarrhea, once an initial four-hour rehydration period is completed, zinc supplementation is recommended. Daily zinc increases the chances of reducing the severity and duration of the diarrhea, and continuing with daily zinc for ten to fourteen days makes diarrhea less likely recur in the next two to three months.

In addition, malnourished children need both potassium and magnesium. This can be obtained by following the above recommendations for the dehydrated child to continue eating within two to three hours of starting rehydration, and including foods rich in potassium as above. Low blood potassium is worsened when base (as in Ringer's/Hartmann's) is given to treat acidosis without simultaneously providing potassium. As above, available home products such as salted and unsalted cereal water, salted and unsalted vegetable broth can be given early during the course of a child's diarrhea along with continued eating. Vitamin A, potassium, magnesium, and zinc should be added with other vitamins and minerals if available.

For a malnourished child with diarrhea from any cause, this should include foods rich in potassium such as bananas, green coconut water, and unsweetened fresh fruit juice.

Diarrhea
The World Health Organization (WHO) recommends rehydrating a severely undernourished child who has diarrhea relatively slowly. The preferred method is with fluids by mouth using a drink called oral rehydration solution (ORS). The oral rehydration solution is both slightly sweet and slightly salty and the one recommended in those with severe undernutrition should have half the usual sodium and greater potassium. Fluids by nasogastric tube may be use in those who do not drink. Intravenous fluids are recommended only in those who have significant dehydration due to their potential complications. These complications include congestive heart failure.

Breast feeding and eating should resume as soon as possible. Drinks such as soft drinks, fruit juices, or sweetened teas are not recommended as they contain too much sugar and may worsen diarrhea. Broad spectrum antibiotics are recommended in all severely undernourished children with diarrhea requiring admission to hospital.

To prevent dehydration readily available fluids, preferably with a modest amount of sugars and salt such as vegetable broth or salted rice water, may be used. The drinking of additional clean water is also recommended. Once dehydration develops oral rehydration solutions are preferred. As much of these drinks as the person wants can be given, unless there are signs of swelling. If vomiting occurs, fluids can be paused for 5–10 minutes and then restarting more slowly. Vomiting rarely prevents rehydration as fluid are still absorbed and the vomiting rarely last long. A severely malnourished child with what appears to be dehydration but who has not had diarrhea should be treated as if they have an infection.

For babies a dropper or syringe without the needle can be used to put small amounts of fluid into the mouth; for children under 2, a teaspoon every one to two minutes; and for older children and adults, frequent sips directly from a cup. After the first two hours, rehydration should be continued at the same or slower rate, determined by how much fluid the child wants and any ongoing diarrheal loses. After the first two hours of rehydration it is recommended that to alternate between rehydration and food.

In 2003, WHO and UNICEF recommended a reduced-osmolarity ORS which still treats dehydration but also reduced stool volume and vomiting. Reduced-osmolarity ORS is the current standard ORS with reasonably wide availability. For general use, one packet of ORS (glucose sugar, salt, potassium chloride, and trisodium citrate) is added to one liter of water; however, for malnourished children it's recommended that one packet of ORS be added to two liters of water along with an extra 50 grams of sucrose sugar and some stock potassium solution.

Malnourished children have an excess of body sodium. Recommendations for home remedies agree with one liter of water (34 oz.) and 6 teaspoons sugar and disagree regarding whether it's then one teaspoon of salt added or only 1/2, with perhaps most sources recommending 1/2 teaspoon of added salt to one liter water.

Low blood sugar
Hypoglycemia, whether known or suspected, can be treated with a mixture of sugar and water. If the child is conscious, the initial dose of sugar and water can be given by mouth. If the child is unconscious, give glucose by intravenous or nasogastric tube. If seizures occur after despite glucose, rectal diazepam is recommended. Blood sugar levels should be re-checked on two hour intervals.

Hypothermia
Hypothermia can occur. To prevent or treat this, the child can be kept warm with covering including of the head or by direct skin-to-skin contact with the mother or father and then covering both parent and child. Prolonged bathing or prolonged medical exams should be avoided. Warming methods are usually most important at night.

Economics
There is a growing realization among aid groups that giving cash or cash vouchers instead of food is a cheaper, faster, and more efficient way to deliver help to the hungry, particularly in areas where food is available but unaffordable. The UN's World Food Program, the biggest non-governmental distributor of food, announced that it will begin distributing cash and vouchers instead of food in some areas, which Josette Sheeran, the WFP's executive director, described as a "revolution" in food aid. The aid agency Concern Worldwide is piloting a method through a mobile phone operator, Safaricom, which runs a money transfer program that allows cash to be sent from one part of the country to another.

However, for people in a drought living a long way from and with limited access to markets, delivering food may be the most appropriate way to help. Fred Cuny stated that "the chances of saving lives at the outset of a relief operation are greatly reduced when food is imported. By the time it arrives in the country and gets to people, many will have died." U.S. law, which requires buying food at home rather than where the hungry live, is inefficient because approximately half of what is spent goes for transport. Cuny further pointed out "studies of every recent famine have shown that food was available in-country — though not always in the immediate food deficit area" and "even though by local standards the prices are too high for the poor to purchase it, it would usually be cheaper for a donor to buy the hoarded food at the inflated price than to import it from abroad."

Ethiopia has been pioneering a program that has now become part of the World Bank's prescribed method for coping with a food crisis and had been seen by aid organizations as a model of how to best help hungry nations. Through the country's main food assistance program, the Productive Safety Net Program, Ethiopia has been giving rural residents who are chronically short of food, a chance to work for food or cash. Foreign aid organizations like the World Food Program were then able to buy food locally from surplus areas to distribute in areas with a shortage of food. Ethiopia been pioneering a program, and Brazil has established a recycling program for organic waste that benefits farmers, urban poor, and the city in general. City residents separate organic waste from their garbage, bag it, and then exchange it for fresh fruit and vegetables from local farmers. As a result, the country's waste is reduced and the urban poor get a steady supply of nutritious food.

Epidemiology
[[Image:Nutritional deficiencies world map - DALY - WHO2004.svg|thumb|[[Disability-adjusted life year]] for nutritional deficiencies per 100,000 inhabitants in 2004. Nutritional deficiencies included: protein-energy malnutrition, iodine deficiency, vitamin A deficiency, and iron deficiency anaemia.

{{legend|#b3b3b3| no data }} {{legend|#ffff65| <200 }} {{legend|#fff200| 200-400 }} {{legend|#ffdc00| 400-600 }} {{legend|#ffc600| 600-800 }} {{legend|#ffb000| 800-1000 }} {{legend|#ff9a00| 1000-1200 }}

{{legend|#ff8400| 1200-1400 }} {{legend|#ff6e00| 1400-1600 }} {{legend|#ff5800| 1600-1800 }} {{legend|#ff4200| 1800-2000 }} {{legend|#ff2c00| 2000-2200 }} {{legend|#cb0000| >2200 }} ]] There were 925 million undernourished people in the world in 2010, an increase of 80 million since 1990. This is despite the world producing enough food to feed everyone — 7 billion people — and could feed almost double — 12 billion people. In 2010 protein-energy malnutrition resulted in 600,000 deaths down from 883,000 deaths in 1990. Other nutritional deficiencies, which include iodine deficiency and iron deficiency anemia, result in another 84,000 deaths. Malnutrition as of 2010 was the cause of 1.4% of all disability adjusted life years. In that year it cause about 1.5 million deaths in women and children.



Society and culture
Roughly $300 million of aid goes to basic nutrition each year, less than $2 for each child below two in the 20 worst affected countries. In contrast, HIV/AIDS, which causes fewer deaths than child malnutrition, received $2.2 billion—$67 per person with HIV in all countries.

The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), a member of the CGIAR consortium, partners with farmers, governments, researchers and NGOs to help farmers grow nutritious crops, such as chickpea, groundnut, pigeonpea, millet and sorghum. This helps their communities have more balanced diets and become more resilient to pests and drought. The Harnessing Opportunities for Productivity Enhancement of Sorghum and Millets in Sub-Saharan Africa and South Asia (HOPE) project, for example, is increasing yields of finger millet in Tanzania by encouraging farmers to grow improved varieties. Finger millet is very high in calcium, rich in iron and fiber, and has a better energy content than other cereals. These characteristics make it ideal for feeding to infants and the elderly.

Some organizations have begun working with teachers, policymakers, and managed food service 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.

The verb form is "malnourish"; "malnourishment" is sometimes used instead of "malnutrition".

Special populations
Undernutrition is an important determinant of maternal and child health, accounting for more than a third of child deaths and more than 10 percent of the total global disease burden according to 2008 studies.

Women
Researchers from the Centre for World Food Studies in 2003 found that the gap between levels of undernutrition in men and women is generally small, but that the gap varies from region to region and from country to country. These small-scale studies showed that female undernutrition prevalence rates exceeded male undernutrition prevalence rates in South/Southeast Asia and Latin America and were lower in Sub-Saharan Africa. Datasets for Ethiopia and Zimbabwe reported undernutrition rates between 1.5 and 2 times higher in men than in women; however, in India and Pakistan, datasets rates of undernutrition were 1.5-2 times higher in women than in men. Intra-country variation also occurs, with frequent high gaps between regional undernutrition rates. Gender inequality in nutrition in some countries such as India is present in all stages of life.

Within the household, there may be differences in levels of malnutrition between men and women, and these differences have been shown to vary significantly from one region to another, with problem areas showing relative deprivation of women. Samples of 1000 women in India in 2008 demonstrated that malnutrition in women is associated with poverty, lack of development and awareness, and illiteracy. The same study showed that gender discrimination in households can prevent a woman's access to sufficient food and healthcare. How socialization affects the health of women in Bangladesh, Najma Rivzi explains in an article about a research program on this topic. In some cases, such as in parts of Kenya in 2006, rates of malnutrition in pregnant women were even higher than rates in children.

Women have unique nutritional requirements, and in some cases need more nutrients than men; for example, women need twice as much calcium as men. Studies on nutrition concerning gender bias within households look at patterns of food allocation, and one study from 2003 suggested that women often receive a lower share of food requirements than men. Gender discrimination, gender roles, and social norms affecting women can lead to early marriage and childbearing, close birth spacing, and undernutrition, all of which contribute to malnourished mothers. Frequent pregnancies with short intervals between them and long periods of breastfeeding add an additional nutritional burden. During pregnancy and breastfeeding, women must ingest enough nutrients for themselves and their child, so they need significantly more protein and calories during these periods, as well as more vitamins and minerals (especially iron, iodine, calcium, folic acid, and vitamins A, C, and K). In 2001 the FAO of the UN reported that iron deficiency afflicted 43 percent of women in developing countries and increased the risk of death during childbirth. A 2008 review of interventions estimated that universal supplementation with calcium, iron, and folic acid during pregnancy could prevent 105,000 maternal deaths (23.6 percent of all maternal deaths). Women in some societies are traditionally given less food than men since men are perceived to have heavier workloads. Household chores and agricultural tasks can be arduous and require additional energy and nutrients; however, physical activity, which largely determines energy requirements, is difficult to estimate. According to the FAO, women are often responsible for preparing food and have the chance to educate their children about beneficial food and health habits, giving mothers another chance to improve the nutrition of their children.

Children
The World Health Organization estimates that malnutrition accounts for 54 percent of child mortality worldwide, about 1 million children. Even mild degrees of malnutrition double the risk of mortality for respiratory and diarrheal disease mortality and malaria. This risk is greatly increased in more severe cases of malnutrition. There are three commonly used measures for detecting malnutrition in children: stunting (extremely low height for age), underweight (extremely low weight for age), and wasting (extremely low weight for height). These measures of malnutrition are interrelated, but studies for the World Bank found that only 9 percent of children exhibit stunting, underweight, and wasting. According to a 2008 review an estimated 178 million children under age 5 are stunted, most of whom live in sub-Saharan Africa. A 2008 review of malnutrition found that about 55 million children are wasted, including 19 million who have severe wasting or severe acute malnutrition. Measurements of a child’s growth provide the key information for the presence of malnutrition, but weight and height measurements alone can lead to failure to recognize kwashiorkor and an underestimation of the severity of malnutrition in children.

The 2008 Copenhagen Consensus estimated that undernutrition causes 35 percent of the disease burden in children younger than 5 years old, and that the nutrition of children 5 years and younger depends strongly on the nutrition level of their mothers during pregnancy and breastfeeding. Infants born to young mothers who are not fully developed are found to have low birth weights. The level of maternal nutrition during pregnancy can affect newborn body size and composition. Iodine-deficiency in mothers usually causes brain damage in their offspring, and some cases cause extreme physical and mental retardation. This affects the children’s ability to achieve their full potential. In 2011 UNICEF reported that thirty percent of households in the developing world were not consuming iodized salt, which accounted for 41 million infants and newborns in whom iodine deficiency could still be prevented. Maternal body size is strongly associated with the size of newborn children. Undernourished girls tend to grow into short adults and are more likely to have small children. Short stature of the mother and poor maternal nutrition stores increase the risk of intrauterine growth retardation (IUGR). However, environmental factors can weaken the effect of IUGR on cognitive performance. Studies in Bangladesh in 2009 found that the mother’s literacy, low household income, higher number of siblings, less access to mass media, less supplementation of diets, unhygienic water and sanitation are associated with chronic and severe malnutrition in children. Prenatal malnutrition and early life growth patterns can alter metabolism and physiological patterns and have lifelong effects on the risk of cardiovascular disease. Children who are undernourished are more likely to be short in adulthood, have lower educational achievement and economic status, and give birth to smaller infants. Children often face malnutrition during the age of rapid development, which can have long-lasting impacts on health. Children suffering from severe acute malnutrition are very thin, but they often also have swollen hands and feet, making the internal problems more evident to health workers. Undernutrition in children causes direct structural damage to the brain and impairs infant motor development and exploratory behavior. Children who are undernourished before age two and gain weight quickly later in childhood and in adolescence are at high risk of chronic diseases related to nutrition. Inadequate food intake, infections, psychosocial deprivation, the environment, and perhaps genetics contribute. Children with severe malnutrition are very susceptible to infection. However, children with chronic diseases like HIV have a higher risk of malnutrition, since their bodies cannot absorb nutrients as well. Diseases such as measles are a major cause of malnutrition in children; thus immunizations present a way to relieve the burden.

Studies have found a strong association between undernutrition and child mortality. Once malnutrition is treated, adequate growth is an indication of health and recovery. Even after recovering from severe malnutrition, children often remain stunted for the rest of their lives. A study in Bangladesh in 2009 reported that rates of malnutrition were higher in female children than male children. Other studies show that, at the national level, differences between undernutrition prevalence rates between young boys and girls are generally small. Girls often have a lower nutritional status in South and Southeastern Asia compared to boys. In other developing regions, the nutritional status of girls is slightly higher. In almost all countries, the poorest quintile of children has the highest rate of malnutrition. However, inequalities in malnutrition between children of poor and rich families vary from country to country, with studies finding large gaps in Peru and very small gaps in Egypt. In 2000, rates of child malnutrition were much higher in low income countries (36 percent) compared to middle income countries (12 percent) and the United States (1 percent).

Measures have been taken to reduce child malnutrition. Studies for the World Bank found that, from 1970–2000, the number of malnourished children decreased by 20 percent in developing countries. Iodine supplement trials in pregnant women have been shown to reduce offspring deaths during infancy and early childhood by 29 percent. However, universal salt iodization has largely replaced this intervention. The Progresa program in Mexico combined conditional cash transfers with nutritional education and micronutrient-fortified food supplements; this resulted in a 10 percent reduction the prevalence of stunting in children 12–36 months old. Milk fortified with zinc and iron reduced the incidence of diarrhea by 18 percent in a study in India. Breastfeeding can reduce rates of malnutrition and dehydration caused by diarrhea, but mothers are sometimes wrongly advised to not breastfeed their children. Breastfeeding has been shown to reduce mortality in infants and young children. Since only 38 percent of children worldwide under 6 months are exclusively breastfed, education programs could have large impacts on children malnutrition rates. However, breastfeeding cannot fully prevent PEM if not enough nutrients are consumed.

Treatment with antibiotics such as amoxicillin or cefdinir improve the response and survival rate of severely malnourished children to an outpatient treatment plan which provided therapeutic food. This confirms the recommendation, "In addition to the provision of RUTF [ready-to-use therapeutic food], children need to receive a short course of basic oral medication to treat infections." contained in "Community-based management of severe acute malnutrition, A Joint Statement by the World Health Organization, the World Food Programme, the United Nations System Standing Committee on Nutrition and the United Nations Children’s Fund."

Elderly
Malnutrition and being underweight are more common in the elderly than in adults of other ages. If elderly people are healthy and active, the aging process alone does not usually cause malnutrition. However, changes in body composition, organ functions, adequate energy intake and ability to eat or access food are associated with aging, and may contribute to malnutrition. Sadness or depression can play a role, causing changes in appetite, digestion, energy level, weight, and well-being. A study on the relationship between malnutrition and other conditions in the elderly found that Malnutrition in the elderly can result from gastrointestinal and endocrine system disorders, loss of taste and smell, decreased appetite and inadequate dietary intake. Poor dental health, ill-fitting dentures, or chewing and swallowing problems can make eating difficult. As a result of these factors, malnutrition is seen to develop more easily in the elderly. Rates of malnutrition tend to increase with age in the elderly population; a study in Clinical Nutrition noted that less than 10 percent of the “young” elderly (up to age 75) are malnourished, while 30 to 65 percent of the elderly in home care, long-term care facilities, or acute hospitals are malnourished. Many elderly people require assistance in eating, which may contribute to malnutrition. Because of this, one of the main requirements of elderly care is to provide an adequate diet and all essential nutrients. Researchers in Australia conducting mini-nutritional assessments (MNAs) reported that malnutrition or risk of malnutrition occurs in 80 percent of elderly people presented to hospitals for admission. Malnutrition and weight loss can contribute to sarcopenia with loss of lean body mass and muscle function. Abdominal obesity or weight loss coupled with sarcopenia lead to immobility, skeletal disorders, insulin resistance, hypertension, atherosclerosis, and metabolic disorders. A paper from the Journal of the American Dietetic Association noted that routine nutrition screenings represent one way to detect and therefore decrease the prevalence of malnutrition in the elderly.