Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is a deficiency, excess, or imbalance of energy, protein and other nutrients which adversely affects the body's tissues and form.
Malnutrition is a category of diseases that includes undernutrition and overnutrition. Undernutrition is a lack of nutrients, which can result in stunted growth, wasting, and being underweight. A surplus of nutrients causes overnutrition, which can result in obesity or toxic levels of micronutrients. In some developing countries, overnutrition in the form of obesity is beginning to appear within the same communities as undernutrition. Malnutrition is reported to occur in US healthcare and worldwide up to 40% of hospitalized patients are estimated to be affected by disease-related malnutrition. Accordingly, a 2019 report by The Lancet Commission suggested expanding the definition of malnutrition to include "all its forms, including obesity, undernutrition, and other dietary risks." The World Health Organization and The Lancet Commission have also identified "[t]he double burden of malnutrition", which occurs from "the coexistence of overnutrition (overweight and obesity) alongside undernutrition (stunted growth and wasting)."
Prevalence
thumb|Number of people undernourished by region
It was estimated in 2017 that nearly one in three persons globally had at least one form of malnutrition: wasting, stunting, vitamin or mineral deficiency, overweight, obesity, or diet-related noncommunicable diseases. Undernutrition is more common in developing countries. Stunting is more prevalent in urban slums than in rural areas.
Studies on malnutrition have the population categorised into different groups including infants, under-five children, children, adolescents, pregnant women, adults and the elderly population. The use of different growth references in different studies leads to variances in the undernutrition prevalence reported in different studies. Some of the growth references used in studies include the National Center for Health Statistics (NCHS) growth charts, WHO reference 2007, Centers for Disease Control and Prevention (CDC) growth charts, National Health and Nutrition Examination Survey (NHANES), WHO reference 1995, Obesity Task Force (IOTF) criteria and Indian Academy of Pediatrics (IAP) growth charts. In 2023, an estimated 28.9 percent of the global population – 2.33 billion people – were moderately or severely food insecure.
In children
thumb|Prevalence of undernourishment by region
The prevalence of undernutrition is highest among children under five. In 2021, an estimated 45% of deaths in children were linked to undernutrition. India has one of the highest burdens of wasting in Asia with over 20% wasted children. However, the burden of undernutrition among under-five children in African countries is much higher. A pooled analysis of the prevalence of chronic undernutrition among under-five children in East Africa was identified to be 33.3%. This prevalence of undernutrition among under-five children ranged from 21.9% in Kenya to 53% in Burundi.
In Tanzania, the prevalence of stunting, among children under five varied from 41% in lowland and 64.5% in highland areas. Undernutrition by underweight and wasting was 11.5% and 2.5% in lowland and 22.% and 1.4% in the highland areas of Tanzania respectively. In South Sudan, the prevalence of undernutrition explained by stunting, underweight and wasting in under-five children were 23.8%, 4.8% and 2.3% respectively. In 28 countries, at least 30% of children were still affected by stunting in 2022.
Vitamin A deficiency affects one third of children under age 5 around the world, leading to 670,000 deaths and 250,000–500,000 cases of blindness. Vitamin A supplementation has been shown to reduce all-cause mortality by 12 to 24%.
In adults
thumb|Most countries either do not have sufficient data or are off track to achieve the 2030 global nutrition targets
As of June 2021, 1.9 billion adults were overweight or obese, and 462 million adults were underweight. In 2020, 900 million women and children had anemia, which is often caused by iron deficiency. More than 3.1 billion people in the world – 42% – were unable to afford a healthy diet in 2021.
Certain groups have higher rates of undernutrition, including elderly people and women (in particular while pregnant or breastfeeding children under five years of age). Undernutrition is an increasing health problem in people aged over 65 years, even in developed countries, especially among nursing home residents and in acute care hospitals. In the elderly, undernutrition is more commonly due to physical, psychological, and social factors, not a lack of food. Age-related reduced dietary intake due to chewing and swallowing problems, sensory decline, depression, imbalanced gut microbiome, poverty and loneliness are major contributors to undernutrition in the elderly population. Malnutrition is also attributed due to wrong diet plan adopted by people who aim to reduce their weight without medical practitioners or nutritionist advice.
Increase in 2020
thumb|Four year old Palestinian girl starved to death, during [[Gaza Famine]]
There has been a global increase in food insecurity and hunger between 2011 and 2020. In 2015, 795 million people (about one in ten people on earth) had undernutrition. It is estimated that between 691 and 783 million people in the world faced hunger in 2022. According to UNICEF, 2.4 billion people were moderately or severely food insecure in 2022, 391 million more than in 2019.
thumb|250px|Projected numbers of undernourished people by FAO shows global malnutrition rates
These increases are partially related to the COVID-19 pandemic, which continues to highlight the weaknesses of current food and health systems. It has contributed to food insecurity, increasing hunger worldwide; meanwhile, lower physical activity during lockdowns has contributed to increases in overweight and obesity. In 2020, experts estimated that by the end of the year, the pandemic could have double the number of people at risk of suffering acute hunger, around 130 million more undernourished people. Similarly, experts estimated that the prevalence of moderate and severe wasting could increase by 14% due to COVID-19; coupled with reductions in nutrition and health services coverage, this could result in over 128,000 additional deaths among children under 5 in 2020 alone.
Other major causes of hunger include manmade conflicts, climate changes, and economic downturns.
Type
Undernutrition
thumb|330x330px|Prevalence of undernourishment (2022–2024 average)
thumb|330x330px|Number of undernourished people (2022–2024 average)
thumb|The prevalence of undernourishment (PoU) was still higher in 2022 than before the pandemic in 58% of countries, and the situation is worse in low-income countries (77%).|330x330px
Undernutrition can occur either due to protein-energy wasting or as a result of micronutrient deficiencies. It adversely affects physical and mental functioning, and causes changes in body composition and body cell mass. Undernutrition is a major health problem, causing the highest mortality rate in children, particularly in those under 5 years, and is responsible for long-lasting physiologic effects. It is a barrier to the complete physical and mental development of children. This condition can have major health consequences.
It is possible to have overnutrition simultaneously with micronutrient deficiencies; this condition is termed the double burden of malnutrition.
Protein-energy malnutrition
'Undernutrition' sometimes refers specifically to protein–energy malnutrition (PEM). This condition involves both micronutrient deficiencies and an imbalance of protein intake and energy expenditure.
Two forms of PEM are kwashiorkor and marasmus; both commonly coexist.
Marasmus (meaning 'to waste away') can result from a sustained diet that is deficient in both protein and energy. This causes their metabolism to adapt to prolong survival. It causes overweight, defined as a body mass index (BMI) of 25 or more, and can lead to obesity (a BMI of 30 or more). Obesity has become a major health issue worldwide. Overnutrition is linked to chronic non-communicable diseases like diabetes, certain cancers, and cardiovascular diseases. Hence identifying and addressing the immediate risk factors has become a major health priority. The recent evidence on the impact of diet-induced obesity in fathers and mothers around the time of conception is identified to negatively program the health outcomes of multiple generations.
According to UNICEF, at least 1 in every 10 children under five is overweight in 33 countries.
Classifying malnutrition
Definition by Gomez and Galvan
In 1956, Gómez and Galvan studied factors associated with death in a group of undernourished children in a hospital in Mexico City, Mexico. They defined three categories of malnutrition: first, second, and third degree. The degree of malnutrition is calculated based on a child's body size compared to the median weight for their age.
{| class="wikitable"
|-
! Degree of PEM
! % of desired body weight for age and sex
|-
| Normal
| 90–100%
|-
| Mild: Grade I (1st degree)
| 75–89%
|-
| Moderate: Grade II (2nd degree)
| 60–74%
|-
| Severe: Grade III (3rd degree)
|<60%
|-
!colspan=16|<small>SOURCE:"Serum Total Protein and Albumin Levels in Different Grades of Protein Energy Malnutrition"</small>
|}
Definition by Waterlow
In the 1970s, John Conrad Waterlow established a new classification system for malnutrition. One advantage of the Waterlow classification is that weight for height can be calculated even if a child's age is unknown.</small>
|}
The World Health Organization frequently uses these classifications of malnutrition, with some modifications. In communities or areas that lack access to safe drinking water, these additional health risks present a critical problem.
Undernutrition plays a major role in the onset of active tuberculosis. It also raises the risk of HIV transmission from mother to child, and increases replication of the virus.
Undernutrition can also cause acute problems, like hypoglycemia (low blood sugar). This condition can cause lethargy, limpness, seizures, and loss of consciousness. Children are particularly at risk and can become hypoglycemic after 4 to 6 hours without food. Dehydration can also occur in malnourished people, and can be life-threatening, especially in babies and small children.
Signs
There are many different signs of dehydration in undernourished people. These can include sunken eyes; a very dry mouth; decreased urine output and/or dark urine; increased heart rate with decreasing blood pressure; and altered mental status.
{| class="wikitable"
|-
! Site !! Sign
|-
| Face || Moon face (in kwashiorkor); shrunken, monkey-like face (in marasmus)
|-
| Eye || Dry eyes; pale conjunctiva; periorbital edema; Bitot's spots (in vitamin A deficiency)
|-
| Mouth || Angular stomatitis; cheilitis; glossitis; parotid enlargement; spongy, bleeding gums (in vitamin C and B<sub>12</sub> deficiencies)
|-
| Teeth || Enamel mottling; delayed eruption
|-
| Hair || Dull, sparse, brittle hair, with thinning of the hair follicles; hypopigmentation; flag sign (alternating bands of light and normal color); broomstick eyelashes; alopecia
|-
| Skin || Dry skin; follicular hyperkeratosis; patchy hyper- and hypopigmentation; erosions; poor wound healing; loose and wrinkled skin (in marasmus); shiny and edematous skin (in kwashiorkor)
|-
| Nail || Koilonychia; thin and soft nail plates; fissures or ridges
|-
| Musculature|| Muscle wasting, particularly in the buttocks and thighs
|-
| Skeletal|| Deformities, usually resulting from deficiencies in calcium, vitamin D, or vitamin C
|-
| Abdomen|| Distended; hepatomegaly with fatty liver; possible ascites
|-
| Cardiovascular|| Bradycardia; hypotension; reduced cardiac output; small vessel vasculopathy
|-
| Neurologic|| Global developmental delay; loss of knee and ankle reflexes; poor memory, often resulting from deficiencies in vitamin B<sub>12</sub> and other B vitamins
|-
| Hematological|| Pallor; petechiae; bleeding diathesis
|-
| Behavior || Lethargic; apathetic; anxious
|-
!colspan=16|<small>Source: "Protein Energy Malnutrition" For example, in children under two years of age, iron deficiency anemia is likely to affect brain function acutely, and probably also chronically. Similarly, folate deficiency has been linked to neural tube defects.
Iodine deficiency is "the most common preventable cause of mental impairment worldwide." "Even moderate [iodine] deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation's development."
Causes and risk factors
thumb|upright=0.75|[[Union Army soldier on his release from Confederate prison, around 1865]]
Social and political
thumb|upright=0.75|A child with extreme malnutrition
Social conditions have a significant influence on the health of people. The social determinants of undernutrition mainly include poor education, poverty, disease burden and lack of women's empowerment. Identifying and addressing these determinants can eliminate undernutrition in the long term. High food prices are a major factor preventing low income households from getting nutritious food. For example, in Bangladesh, low socioeconomic status was associated with chronic malnutrition since it inhibited purchase of nutritious foods (like milk, meat, poultry, and fruits). The probability of overnutrition is significantly higher in higher-income families than in disadvantaged families. The economist Amartya Sen observes that, in recent decades, famine has always been a problem of food distribution, purchasing power, and/or poverty, since there has always been enough food for everyone in the world.
There are also sociopolitical causes of malnutrition. For example, the population of a community might be at increased risk for malnutrition if government is poor and the area lacks health-related services. On a smaller scale, certain households or individuals may be at an even higher risk due to differences in income levels, access to land, or levels of education. Community plays a crucial role in addressing the social causes of malnutrition. For example, communities with high social support and knowledge sharing about social protection programs can enable better public service demands. Better public service demands and social protection programs minimise the risk of malnutrition in these communities.
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 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, should be used as fuel instead of crops.
In some developing countries, overnutrition (in the form of obesity) is beginning to appear in the same communities where malnutrition occurs. Overnutrition increases with urbanisation, food commercialisation and technological developments and increases physical inactivity. Variations in the health status of individuals in the same society are associated with the societal structure and an individual's socioeconomic status which leads to income inequality, racism, educational differences and lack of opportunities.
Diseases and conditions
Infectious diseases which increase nutrient requirements, such as gastroenteritis, pneumonia, malaria, and measles, can cause malnutrition.
Malnutrition can also result from abnormal nutrient loss due to diarrhea or chronic small bowel illnesses, like Crohn's disease or untreated coeliac disease. "Secondary malnutrition" can result from increased energy expenditure.
In infants, a lack of breastfeeding may contribute to undernourishment.
Dietary practices
Undernutrition
Undernutrition due to lack of adequate breastfeeding is associated with the deaths of an estimated one million children annually. Illegal advertising of breast-milk substitutes contributed to malnutrition and continued three decades after its 1981 prohibition under the WHO International Code of Marketing Breast Milk Substitutes.
Maternal malnutrition can also factor into the poor health or death of a baby. Over 800,000 neonatal deaths have occurred because of deficient growth of the fetus in the mother's womb.
Deriving too much of one's diet from a single source, such as eating almost exclusively potato, maize or rice, can cause malnutrition. This may either be from a lack of education about proper nutrition, only having access to a single food source, or from poor healthcare access and unhealthy environments.
It is not just the total amount of calories that matters but specific nutritional deficiencies such as vitamin A deficiency, iron deficiency or zinc deficiency can also increase risk of death.
Overnutrition
thumb|262x262px|Chart showing a trend between obesity and diabetes over the years
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.
Overnutrition also occurs in developing countries. It has appeared in parts of developing countries where income is on the rise. In China, consumption of high-fat foods has increased, while consumption of rice and other goods has decreased. Without subsidies, few (if any) farmers in developing countries can afford fertilizer at market prices. This leads to low agricultural production, low wages, and high, unaffordable food prices.
Future threats
thumb|260px|Projected world population by 2100 based on the UN's medium population scenario.
In the future, variety of factors could potentially disrupt global food supply and cause widespread malnutrition. According to UNICEF's projections, it is projected that almost 600 million people will be chronically undernourished in 2030.
Global warming is of importance to food security. Almost all malnourished people (95%) live in the tropics and subtropics, where the climate is relatively stable. According to the Intergovernmental Panel on Climate Change report in 2007, temperature increases in these regions are "very likely." Even small changes in temperatures can make extreme weather conditions occur more frequently. Other central Asian nations experienced similar losses. 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, and decreases food security in these regions.
Another threat is colony collapse disorder, a phenomenon where bees die in large numbers. Since many agricultural crops worldwide are pollinated by bees, colony collapse disorder represents a threat to the global food supply.
Prevention
thumb|right|[[Irrigation canals have opened dry desert areas of Egypt to agriculture.]]
Reducing malnutrition is key part of the United Nations' Sustainable Development Goal 2 (SDG2), "Zero Hunger", which aims to reduce malnutrition, undernutrition, and stunted child growth. Managing severe acute undernutrition in a community setting has received significant research attention.
thumb|[[World population supported with and without synthetic nitrogen fertilizers.]]
The Green Revolution was possible in Asia because of existing infrastructure and institutions, such as a system of roads and public seed companies that made seeds available. These resources were in short supply in Africa, decreasing the Green Revolution's impact on the continent.
For example, almost five million of the 13 million people in Malawi used to need emergency food aid. However, in the early 2000s, the Malawian government changed its agricultural policies, and implemented subsidies for fertilizer and seed introduced against World Bank strictures. By 2007, farmers were producing record-breaking corn harvests. Corn production leaped to 3.4 million in 2007 compared to 1.2 million in 2005, making Malawi a major food exporter. Proponents for investing in agriculture include Jeffrey Sachs, who argues that wealthy countries should invest in fertilizer and seed for Africa's farmers.
Imported Ready to Use Therapeutic Food (RUTF) has been used to treat malnutrition in northern Nigeria. Some Nigerians also use soy kunu, a locally sourced and prepared blend consisting of peanut, millet and soybeans.
New technology in agricultural production has great potential to combat undernutrition. It makes farming easier, thus improving agricultural yields. By increasing farmers' incomes, this could reduce poverty. It would also open up area which farmers could use to diversify crops for household use.
The World Bank claims to be part of the solution to malnutrition, asserting that countries can best break the cycle of poverty and malnutrition by building export-led economies, which give them the financial means to buy foodstuffs on the world market.
Child malnutrition can worsen with food price inflation. The 2021 to 2023 food price surge is associated with higher rates of wasting among children under five years of age. A 10% increase in food prices is associated with a 2.7% to 4.3% rise in overall wasting and a 4.8 to 6.1 percent increase in severe wasting among children under five years of age.
Economics
Many aid groups have found that giving cash assistance (or cash vouchers) is more effective than donating food. Particularly in areas where food is available but unaffordable, giving cash assistance is a cheaper, faster, and more efficient way to deliver help to the hungry. In 2008, the UN's World Food Programme, the biggest non-governmental distributor of food, announced that it would 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 piloted a method of giving cash assistance using a mobile phone operator, Safaricom, which runs a money transfer program that allows cash to be sent from one part of a country to another. U.S. law requires food aid to be purchased at home rather than in the countries where the hungry live; this is inefficient because approximately half of the money spent goes for transport.
thumb|A soup kitchen in [[Montreal, Quebec, Canada in 1931]]
Food banks and soup kitchens address malnutrition in places where people lack money to buy food. A basic income has been proposed as a way to ensure that everyone has enough money to buy food and other basic needs. This is a form of social security in which all citizens or residents of a country regularly receive an unconditional sum of money, either from a government or some other public institution, in addition to any income received from elsewhere.
Successful initiatives
Ethiopia pioneered a program that later became part of the World Bank's prescribed method for coping with a food crisis. Through the country's main food assistance program, the Productive Safety Net Program, Ethiopia provided rural residents who were chronically short of food a chance to work for food or cash. Foreign aid organizations like the World Food Programme were then able to buy food locally from surplus areas to distribute in areas with a shortage of food. Aid organizations now view the Ethiopian program as a model of how to best help hungry nations.
Successful initiatives also include Brazil's recycling program for organic waste, which benefits farmers, the 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. This reduces the country's waste while giving the urban poor a steady supply of nutritious food.]]
Restricting population size is a proposed solution to malnutrition. Thomas Malthus argues that population growth can be controlled by natural disasters and by voluntary limits through "moral restraint." Robert Chapman suggests that government policies are a necessary ingredient for curtailing global population growth. The United Nations recognizes that poverty and malnutrition (as well as the environment) are interdependent and complementary with population growth. According to the World Health Organization, "Family planning is key to slowing unsustainable population growth and the resulting negative impacts on the economy, environment, and national and regional development efforts". However, more than 200 million women worldwide lack adequate access to family planning services.
There are different theories about what causes famine. Some theorists, like the Indian economist Amartya Sen, believe that the world has more than enough resources to sustain its population. In this view, malnutrition is caused by unequal distribution of resources and under- or unused arable land. For example, Sen argues 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."
Breastfeeding
In 2016, estimates suggested that more widespread breastfeeding could prevent about 823,000 deaths annually of children under age 5. In addition to reducing infant deaths, breast milk provides an important source of micronutrients - which are clinically proven to bolster children's immune systems – and provides long-term defenses against non-communicable and allergic diseases. Breastfeeding may improve cognitive abilities in children, and correlates strongly with individual educational achievements. As previously noted, lack of proper breastfeeding is a major factor in child mortality rates, and is a primary determinant of disease development for children. The medical community recommends exclusively breastfeeding infants for 6 months, with nutritional whole food supplementation and continued breastfeeding up to 2 years or older for overall optimal health outcomes. Exclusive breastfeeding is defined as giving an infant only breast milk for six months as a source of food and nutrition.
In April 2012, a number of countries signed the Food Assistance Convention, the world's first legally binding international agreement on food aid. The following month, the Copenhagen Consensus recommended that politicians and private sector philanthropists should prioritize interventions against hunger and malnutrition to maximize the effectiveness of aid spending. The Consensus recommended prioritizing these interventions ahead of any others, including the fights against malaria and AIDS.
In June 2015, the European Union and the Bill & Melinda Gates Foundation launched a partnership to combat undernutrition, especially in children. The program was first implemented in Bangladesh, Burundi, Ethiopia, Kenya, Laos and Niger. It aimed to help these countries improve information and analysis about nutrition, enabling them to develop effective national nutrition policies.
Also in 2015, the UN's Food and Agriculture Organization created a partnership aimed at ending hunger in Africa by 2025. The African Union's Comprehensive Africa Agriculture Development Programme (CAADP) provided the framework for the partnership. It includes a variety of interventions, including support for improved food production, a strengthening of social protection, and integration of the right to food into national legislation.
The EndingHunger campaign is an online communication campaign whose goal is to raise awareness about hunger. The campaign has created viral videos depicting celebrities voicing their anger about the large number of hungry people in the world.
After the Millennium Development Goals expired in 2015, the Sustainable Development Goals became the main global policy focus to reduce hunger and poverty. In particular, Goal 2: Zero Hunger sets globally agreed-upon targets to wipe out hunger, end all forms of malnutrition, and make agriculture sustainable. The partnership Compact2025 develops and disseminates evidence-based advice to politicians and other decision-makers, with the goal of ending hunger and undernutrition by 2025. The International Food Policy Research Institute (IFPRI) led the partnership, with the involvement of UN organisations, non-governmental organizations (NGOs), and private foundations.
Treatment
thumb|A malnourished Afghan child being treated by a medical team
thumb|right|A Somali boy receiving treatment for malnourishment at a health facility
Improving nutrition
Efforts such as infant and young child feeding practices to improve nutrition are some of the common forms of development aid. Interventions often promote breastfeeding to reduce rates of malnutrition and death in children. For example, interventions with commodities such as ready to use therapeutic foods, ready to use supplementary foods, micronutrient intervention and vitamin supplementation were identified to significantly improve nutrition, reduce stunting and prevent diseases in communities with severe acute malnutrition. UNICEF provides nutritional counselling services for malnourished children in Afghanistan.
Sending food and money is a common form of development aid, aimed at feeding hungry people. Some strategies help people buy food within local markets. Simply feeding students at school is insufficient. reducing poverty, and improving sanitation.
Identifying malnourishment
Measuring children is crucial to identifying malnourishment. In 2000, the United States Centers for Disease Control and Prevention (CDC) established the International Micronutrient Malnutrition Prevention and Control (IMMPaCt) program. It tested children for malnutrition by conducting a three-dimensional scan, using an iPad or a tablet. Its objective was to help doctors provide more efficient treatments. There may be some chance of error when using this method. The assessment tool has fair to medium reliability in the identification of children at risk of malnutrition.
Regularly measuring and charting children's growth and including activities to promote health (an intervention called growth monitoring and promotion, also known as GPM) is often considered by policy makers and is recommended by the World Health Organization. This program is often performed at the same time as a child has their regular immunizations. Despite widespread use of this type of program, further studies are needed to understand the impact of these programs on overall child health and how to better address faltering growth in a child and improve practices related to feeding children in lower to middle income countries.
Routine antibiotics are usually recommended because malnutrition weakens the immune system, causing a high risk of infection.
A severely malnourished child who appears to have dehydration, but has not had diarrhea, should be treated as if they have an infection.
Bangladeshi model
thumb|Baby with protein malnutrition due to insufficient amount of nutrients
In response to child malnutrition, the Bangladeshi government recommends ten steps for treating severe malnutrition: A 2015 systematic review of 32 studies found that there are limited benefits when children under 5 receive supplementary feeding, especially among younger, poorer, and more undernourished children.
However, specially formulated foods do appear to be useful in treating moderate acute malnutrition in the developing world. These foods may have additional benefits in humanitarian emergencies, since they can be stored for years, can be eaten directly from the packet, and do not have to be mixed with clean water or refrigerated. In young children with severe acute malnutrition, it is unclear if ready-to-use therapeutic food differs from a normal diet.
Severely malnourished individuals can experience refeeding syndrome if fed too quickly. Refeeding syndrome can result regardless of whether food is taken orally, enterally or parenterally.
Some manufacturers have fortified everyday foods with micronutrients before selling them to consumers. For example, flour has been fortified with iron, zinc, folic acid, and other B vitamins like thiamine, riboflavin, niacin and vitamin B12. After reviewing a variety of development proposals, The Copenhagen Consensus, a group of economists who reviewed a variety of development proposals, ranked micronutrient supplementation as its number-one treatment strategy.
In malnourished people with diarrhea, zinc supplementation is recommended following an initial four-hour rehydration period. Daily zinc supplementation can help reduce the severity and duration of the diarrhea. Additionally, continuing daily zinc supplementation for ten to fourteen days makes diarrhea less likely to recur in the next two to three months.
Malnourished children also need both potassium and magnesium. Within two to three hours of starting rehydration, children should be encouraged to take food, particularly foods rich in potassium
Malnourished people with diarrhea (especially children) should be encouraged to drink fluids; the best choices are fluids with modest amounts of sugar and salt, like vegetable broth or salted rice water.<!--
Reduced-osmolarity ORS is the current standard of care for oral rehydration therapy, with reasonably wide availability. Introduced in 2003 by WHO and UNICEF, reduced-osmolarity solutions contain lower concentrations of sodium and glucose than original ORS preparations. Reduced-osmolarity ORS has the added benefit of reducing stool volume and vomiting while simultaneously preventing dehydration. Packets of reduced-osmolarity ORS include glucose, table salt, potassium chloride, and trisodium citrate. For general use, each packet should be mixed with a liter of water. However, for malnourished children, experts recommend adding a packet of ORS to two liters of water, along with an extra 50 grams of sucrose and some stock potassium solution.
People who have no access to commercially available ORS can make a homemade version using water, sugar, and table salt. Experts agree that homemade ORS preparations should include one liter (34 oz.) of clean water and of sugar; however, they disagree about whether they should contain half a teaspoon of table salt or a full teaspoon. Most sources recommend using half a teaspoon of salt per liter of water. However, people with malnutrition have an excess of body sodium. Otherwise, they should receive glucose by intravenous or nasogastric tube. If seizures occur (and continue after glucose is given), rectal diazepam may be helpful. Blood sugar levels should be re-checked on two-hour intervals. The GHI is updated once a year. The data from the 2015 report shows that Hunger levels have dropped 27% since 2000. Fifty two countries remain at serious or alarming levels. In addition to the latest statistics on Hunger and Food Security, the GHI also features different special topics each year. The 2015 report include an article on conflict and food security.
People affected
The United Nations estimated that there were 821 million undernourished people in the world in 2017. This is using the UN's definition of 'undernourishment', where it refers to insufficient consumption of raw calories, and so does not necessarily include people who lack micro nutrients.
Malnutrition, as of 2010, was the cause of 1.4% of all disability adjusted life years.
{| class="wikitable"
|+Number of undernourished globally
!Year!!2005!!2006!!2007!!2008!!2009!!2010!!2011!!2012!!2013
|-
!Number in millions
|793.4||746.5||691.0||663.1||661.8||597.8||578.3||580.0||572.3
|-
!Percentage (%)
|12.1%||11.2%||10.3%||9.7%||9.6%||8.6%||8.2%||8.1%||7.9%
|-
!Year
!2014
!2015
!2016
!2017
!2018
!2019
!2020
!2021
!2022
|-
!Number in millions
|563.9
|588.9
|586.4
|571.8
|586.8
|612.8
|701.4
|738.9
|735.1
|-
!Percentage (%)
|7.7%
|7.9%
|7.8%
|7.5%
|7.6%
|7.9%
|8.9%
|9.3%
|9.2%
|}
{| class="wikitable"
|+Number of undernourished in the developing world<!--Note that the UN no longer seems to track this specific statistic-->
!Year!!1970!!1980!!1991!!1996!!2002!!2004!!2006||2011
|-
!Number in millions
|875||841||820||790||825||848||927||805
|-
!Percentage (%)
|37%||28%||20%||18%||17%||16%||17%||14%
|}
Mortality
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.
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 such as measles, pneumonia and diarrhea, but malnutrition actually causes diseases, and can be fatal in its own right.
thumb|Starving children during the [[Russian famine of 1921–1922]]
According to historian Michael Worboys, malnutrition was essentially discovered, and the science of nutrition established, between World War I and World War II. Advances built on prior works like Casimir Funk's 1912 formulisation of the concept of vitamins. Scientific study of malnutrition increased in the 1920s and 1930s, and grew even more common after World War II.
Non-governmental organizations and United Nations agencies began to devote considerable energy to alleviating malnutrition around the world. The exact methods and priorities for doing this tended to fluctuate over the years, with varying levels of focus on different types of malnutrition like Kwashiorkor or Marasmus; varying levels of concern on protein deficiency compared to vitamins, minerals and lack of raw calories; and varying priorities given to the problem of malnutrition in general compared to other health and development concerns. The green Revolution of the 1950s and 1960s saw considerable improvement in capability to prevent malnutrition.
One of the first official global documents addressing Food security and global malnutrition was the 1948 Universal Declaration of Human Rights(UDHR). Within this document it stated that access to food was part of an adequate right to a standard of living. The Right to food was asserted in the International Covenant on Economic, Social and Cultural Rights, a treaty adopted by the United Nations General Assembly on December 16, 1966. The Right to food is a human right for people to feed themselves in dignity, be free from hunger, food insecurity, and malnutrition. As of 2018, the treaty has been signed by 166 countries, by signing states agreed to take steps to the maximum of their available resources to achieve the right to adequate food.
However, after the 1966 International Covenant the global concern for the access to sufficient food only became more present, leading to the first ever World Food Conference that was held in 1974 in Rome, Italy. The Universal Declaration on the Eradication of Hunger and Malnutrition was a UN resolution adopted November 16, 1974, by all 135 countries that attended the 1974 World Food Conference. This non-legally binding document set forth certain aspirations for countries to follow to sufficiently take action on the global food problem. Ultimately this document outline and provided guidance as to how the international community as one could work towards fighting and solving the growing global issue of malnutrition and hunger.
Adoption of the right to food was included in the Additional Protocol to the American Convention on Human Rights in the area of Economic, Social, and Cultural Rights, this 1978 document was adopted by many countries in the Americas, the purpose of the document is, "to consolidate in this hemisphere, within the framework of democratic institutions, a system of personal liberty and social justice based on respect for the essential rights of man."
A later document in the timeline of global initiatives for malnutrition was the 1996 Rome Declaration on World Food Security, organized by the Food and Agriculture Organization. This document reaffirmed the right to have access to safe and nutritious food by everyone, also considering that everyone gets sufficient food, and set the goals for all nations to improve their commitment to food security by halving their number of undernourished people by 2015. In 2004 the Food and Agriculture Organization adopted the Right to Food Guidelines, which offered states a framework of how to increase the right to food on a national basis.
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.
Children
thumb|right|Malnourished children in Niger, during the 2005 famine
Undernutrition adversely affects the cognitive development of children, contributing to poor earning capacity and poverty in adulthood. The development of childhood undernutrition coincides with the introduction of complementary weaning foods which are usually nutrient deficient. The World Health Organization estimated in 2008 that malnutrition accounted for 54 percent of child mortality worldwide, There is a strong association between undernutrition and child mortality.
Another estimate in 2008 also by WHO stated that childhood underweight was the cause for about 35% of all deaths of children under the age of five years worldwide. Over 90% of the stunted children below five years of age live in sub-Saharan Africa and South Central Asia.
Women
thumb|[[Migrant Mother by Dorothea Lange (1936)]]
thumb|183x183px|Starved girl
In 2022, more than 1 billion adolescent girls and women suffered from undernutrition, according to UNICEF's 2023 report "Undernourished and Overlooked: A Global Nutrition Crisis in Adolescent Girls and Women". The gender gap in food insecurity more than doubled between 2019 (49 million) and 2021 (126 million). The report shows that globally, 30% of women aged 15–49 years are living with anaemia while 10 per cent of women aged 20–49 years suffer from underweight. South Asia, West and Central Africa and Eastern and Southern Africa are home to 60% of women with anaemia and 65% of women being underweight. In contrast, overweight is affecting more than 35% of women aged 20–49 years, of which 13% are living with obesity. Gender inequality in nutrition in some countries such as India is present in all stages of life.
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. 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 in some societies are traditionally given less food than men since men are perceived to have heavier workloads.
Pregnancy and breastfeeding
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). Malnutrition has been found to affect three-quarters of UK women aged 16–49 indicated by them having less folic acid than the WHO recommended levels.
Frequent pregnancies with short intervals between them and long periods of breastfeeding add an additional nutritional burden.
Team Nutrition has created "MyPlate eBooks" this includes 8 different eBooks to download for free. These eBooks contain drawings to color, audio narration, and a large number of characters to make nutrition lessons entertaining for children.
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. 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. Poor dental health, ill-fitting dentures, or chewing and swallowing problems can make eating difficult.
Rates of malnutrition tend to increase with age with less than 10 percent of the "young" elderly (up to age 75) 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. Providing the different nutrients such as protein and energy keeps even small but consistent weight gain.
In Australia 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.