Current Status + Progress
Malnutrition rates remain alarming: stunting is declining too slowly while wasting still impacts the lives of far too many young children

Nearly half of all deaths in children under 5 are attributable to undernutrition, translating into the loss of about 3 million young lives a year. Undernutrition puts children at greater risk of dying from common infections, increases the frequency and severity of such infections, and​ delays recovery.​

The interaction between undernutrition and infection can create a potentially lethal cycle of worsening illness and deteriorating nutritional status. Poor nutrition in the first 1,000 days of a child’s life can also lead to stunted growth, which is associated with impaired cognitive ability and reduced school and work performance.

We are still far from a world without malnutrition. While the 2018 edition of the joint malnutrition estimates shows that ​stunting prevalence has been declining since the year 2000, nearly one in four ​ – 151 million children under 5 –were stunted in 2017​,​ and 51 million suffered from wasting.  Meanwhile, the number of overweight children worldwide has ​remained stagnant for more than a decade.

Measures of child undernutrition are used to track development progress. In the Post-2015 Development Era, estimates of child malnutrition will help determine whether the world is on track to achieve the Sustainable Development Goals – particularly, goal 2 to “end hunger, achieve food security and improved nutrition, and promote sustainable agriculture”.

Stunting

In 2017, three regions had very high rates of stunting with more than one third ​of children ​affected. On the other hand, four regions had low or very low rates of stunting. However, vast disparities within the low prevalence regions can exist. In Latin America and the Caribbean, for example, despite the low rate overall, some ​individual ​countries face​d​ medium​, high, and in some cases very high stunting rates​. Chronic undernutrition in Latin America and Caribbean ​can vary widely between neighboring countries: Children in one country can have a very low stunting rate with less than 1 in 40 affected, while more than 1 in 10 of their peers in the country next door are at a disadvantage due to the irreversible physical and cognitive damage that can accompany stunted growth.

In three regions, stunting affects one in every three children
Percentage of children under 5 who are stunted, 2017

Source: UNICEF, WHO, World Bank Joint Child Malnutrition dataset, May 2018

Note: Country Data are the most recent available estimate between 2011 and 2017; exceptions where older data (2005-2010) are shown are denoted with an asterisk (*) and where only data prior to 2005 are available the dark grey color denoting no recent data is used 1Eastern Europe and Central Asia region does not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution)

In 2017, 22.2 per cent, or just under one in four children under age 5 worldwide had stunted growth. That said, overall trends are positive. Between 2000 and 2017, stunting prevalence globally declined from 32.6 per cent to 22.2 per cent, and the number of children affected fell from 198 million to 151 million. In 2017, nearly two out of five stunted children lived in South Asia while more than one in three lived in sub-Saharan Africa.

Globally, stunting declined from one in three to just under one in four between 2000 and 2017
Percentage of children under 5 who are stunted, by region, 2000 to 2017

Notes* The Eastern Europe and Central Asia sub-region estimates not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution). . **The Northern America regional average is based only on United States data only, hence confidence intervals are not available.  The percentage change since 2000 is only shown where the change is significantly different.

Source: UNICEF/WHO/World Bank Joint Child Malnutrition Estimates, May 2018 edition.

 

Between 2000 and 2017, the number of stunted children under 5 worldwide declined from 198 million to 151 million. At the same time, numbers have increased at an alarming rate in West and Central Africa - from 22.8 million to 28.9 million.
Number (millions) of children under 5 who are stunted, by region, 2000 and 2017

Notes: * The Eastern Europe and Central Asia sub-region estimates do not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution.**The Northern America regional average is based only on United States data only, hence confidence intervals are not available. The percentage change since 2000 is only shown where the change is significantly different.

Source:  UNICEF/WHO/World Bank Joint Child Malnutrition Estimates, May 2018 edition.

Overweight

Worldwide in 2017, 38 million, or 5.6 per cent, of children under age 5 were overweight. Eastern Europe and Central Asia had the highest overweight prevalence in 2017 with 14.8 per cent affected, followed by Middle East and North Africa at 10.9 per cent and North America at 7.9 per cent. The lowest overweight prevalence in 2017 was seen in South Asia, at 3.0 per cent, followed by West and Central Africa at 4.3 per cent. East Asia and the Pacific had the highest number of overweight children in 2017 with 8.9 million affected, followed by Middle East and North Africa with an estimated 5.3 million overweight. Overall the two Asian regions (East Asia and the Pacific and South Asia) account for more than one out of every three overweight children in the world. Eastern Europe and Central Asia as well as North America are the only regions that have seen a statistically significant increase in number of overweight children between 2000 and 2017.

The prevalence of overweight under-fives has increased significantly between 2000 and 2017 in Eastern Europe and Central Asia
Percentage of children under 5 (in millions) who are overweight, by region, 2000 to 2017

Notes: * The Eastern Europe and Central Asia sub-region estimates do not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution).  The percentage change since 2000 is only shown where the change is significantly different.

Source:  UNICEF/WHO/World Bank Joint Child Malnutrition Estimates, May 2018 edition.

The number of overweight under-fives has increased significantly between 2000 and 2017 in Eastern Europe and Central Asia
Number of children under 5 (in millions) who are overweight, by region, 2000 to 2017

Notes: * Eastern Europe and Central Asia region does not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution).  The percentage change since 2000 is only shown where the change is significantly different.

Source:  UNICEF/WHO/World Bank Joint Child Malnutrition Estimates, May 2018 edition.

Wasting and Severe Wasting

In 2017 globally, 51 million children under five were wasted of which 16 million were severely wasted. This translates into a prevalence of 7.5 per cent and 2.4 per cent, respectively. In 2017, more than half of all wasted children lived in South Asia and about one quarter in sub-Saharan Africa, with similar proportions for severely wasted children. At nearly 16.0 per cent, South Asia’s wasting prevalence represents a situation requiring a serious need for intervention with appropriate treatment programmes. Under-five wasting and severe wasting are highly sensitive to change. Thus, estimates for these indicators are only reported for current levels (2017).

The prevalence of wasting in South Asia is so severe, at 15.9 per cent

Map Disclaimer

Percentage of children under 5 who are wasted, by region, 2017

Notes: Data are the most recent available estimate between 2011 and 2017; exceptions where older data (2005-2010) are shown are denoted with an asterisk(*) and where only data prior to 2005 are available the dark grey color denoting no recent data is used. 1The Eastern Europe and Central Asia sub-region estimate does not include Russian Federation due to missing data; consecutive low population coverage for the 2017 estimate (interpret with caution).

Source:  UNICEF, WHO, World Bank Joint Child Malnutrition dataset, May 2018 edition

Disparities

In almost all countries with available data, stunting rates are higher among boys than girls.  While analyses to determine underlying causes for this phenomenon are underway, an initial review of the literature suggests that the higher risk for preterm birth among boys (which is inextricably linked with lower birth weight) is a potential reason for this sex-based disparity in stunting.

The stunting rate is more than double among the poorest children when compared to the richest
Percentage of children under 5 who are stunted, by wealth quintile and by region, 2016

Notes: Analysis is based on a subset of 92 countries with recent (2011-2017) data by wealth quintile groupings covering 69 per cent of the global population. Regional estimates are presented only where adequate population coverage (≥50 per cent) is met. To meet adequate population coverage, *East Asia and the Pacific does not include China, **Latin America and Caribbean does not include Brazil and ***Eastern Europe and Central Asia does not include Russian Federation.

Source: UNICEF global database, 2017, based on Multiple Indicator Cluster Surveys (MICS), Demographic and Health Surveys (DHS) and other nationally representative surveys.

Children from the poorest 20 per cent of the population have stunting rates that are double the rate in comparison with the richest quintile. In South Asia, the absolute disparities between the richest and poorest children in regard to stunting are greater than in any other region. While the overall rates are lower, the relative disparities are greatest in Latin America and the Caribbean where the rate among the poorest is more than 4 times higher than among the richest.

 

An analysis of 54 countries with comparable trend data between around 2000 and around 2014 shows that gaps between the poorest 20 per cent and richest 20 per cent of children under five have closed by at least 20 per cent in the majority of upper-middle-income countries. However, in almost all low income countries, this gap has either remained the same or increased.

The rich poor gap is increasing or remaining the same in the majority of low- income countries with available trend data
Relative change in gap between richest and poorest for % of stunted children under-age five, between 2000 and 2014

Source: UNICEF (2015) Progress for Children: Beyond Averages – Learning from the MDGs: based on UNICEF global databases, 2015, based on Multiple Indicator Cluster Surveys (MICS), Demographic and Health Surveys (DHS), and other nationally representative sources.

REFERENCES

UNICEF, Progress for Children Beyond Averages: Learning from the MDGs, New York, 2015

Black, R.E., et al., ‘Maternal and Child Undernutrition and Overweight in Low-income and Middle-income Countries’, Lancet, vol. 382, no. 9890, 3 August 2013, pp. 427–451.

Blencowe H et al. (2013). Preterm birth–associated neurodevelopmental impairment estimates at regional and global levels for 2010. Pediatric Research Volume 74: No s1, December 2013.

de Onis, Mercedes, et al., Comparison of the World Health Organization (WHO) Child Growth Standards and the National Center for Health Statistics/WHO International Growth Reference: Implications for child health programmes’, Public Health Nutrition, vol. 9, no. 7, 2006, pp. 942–947.

de Onis, Mercedes, et al., ‘Estimates of Global Prevalence of Childhood Underweight in 1990 and 2015, JAMA, vol. 291, 2004, pp. 2600–2606.

UNICEF, Improving Child Nutrition: The achievable imperative for global progress, UNICEF, New York, 2013.

UNICEF, ‘Technical Note: Age-adjustment of child anthropometry estimates, UNICEF, New York, 2010.

UNICEF, ‘Technical Note: How to calculate average annual rate of reduction (AARR) of underweight prevalence‘, UNICEF, New York, 2007.

Access The Data
Nutritional Status
UNICEF/WHO/World Bank joint child malnutrition estimates: stunting (national and disaggregated) Download Data
UNICEF/WHO/World Bank joint child malnutrition estimates : severe wasting (national and disaggregated) Download Data
UNICEF/WHO/World Bank joint child malnutrition estimates: wasting (national and disaggregated) Download Data
UNICEF/WHO/World Bank joint child malnutrition estimates database: overweight (national and disaggregated) Download Data
UNICEF/WHO/World Bank joint child malnutrition estimates (country level) Download Data
UNICEF/WHO/World Bank joint child malnutrition estimates (global and regional) Download Data
Overlapping malnutrition estimates Download Data
Recent Resources

UNICEF-WHO-The World Bank: Joint Child Malnutrition Estimates – 2018 edition

May 14, 2018

The UNICEF, WHO and the World Bank inter-agency team regularly updates joint global and regional estimates of child malnutrition. These estimates of prevalence and numbers for child stunting, overweight, wasting and severe wasting are derived for the global population as well as by regional groupings of United Nations (UN) regions and sub-regions, Sustainable Development Goals (SDG),

Download the publication | Access the dashboard | Access the regional classifications | Access the global and regional dataset | Access the country-level dataset

UNICEF-WHO-The World Bank: Joint Child Malnutrition Estimates 2018 Edition – Interactive Dashboard

May 14, 2018

This interactive dashboard visualizes the latest child malnutrition estimates for the period 1990-2016. These estimates of prevalence and numbers for child stunting, overweight, wasting and severe wasting are derived by United Nations (UN), Millennium Development Goal (MDG), Sustainable Development Goal (SDG),UNICEF, WHO and World Bank regions, as well as World Bank income group classifications.

Open the dashboard | Access the regional classifications | Download the publication | Access the global and regional dataset | Access the country-level dataset

Global Nutrition Report 2017: Nourishing the SDGs

Nov 4, 2017

Almost every country in the world now faces a serious nutrition-related challenge whether stemming from undernutrition or overweight and obesity, with 1 in 3 people affected. The report focuses on how improving nutrition can have a powerful multiplier effect across the UN Sustainable Development Goals. Indeed, it indicates that it will be a challenge to achieve any Sustainable Development Goal without addressing nutrition.

Download Summary Report | Download Full Report

Nutrition Targets Tracking Tool

Feb 9, 2017

The tracking tool allows users to explore scenarios taking into account different rates of progress for the six World Health Assembly (WHA) Nutrition targets and the time left to 2025 using the latest global databases such as the UNICEF-WHO-World Bank joint malnutrition estimates for stunting, wasting and overweight. The six WHO targets on nutrition were set at the global level as default national targets included in this tool, but countries can define their own national targets for contributing to each of the global targets.

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Notes on the Data

INDICATORS

Indicator name

Definition

Numerator

Denominator

Colloquial definition

Stunting Number of under-fives falling below minus 2 standard deviations (moderate and severe) and minus 3 standard deviations (severe) from the median height-for-age of the reference* population Children under 5 years of age in the surveyed population Stunting refers to a child who is too short for his or her age. These children can suffer severe irreversible physical and cognitive damage that accompanies stunted growth. The devastating effects of stunting can last a lifetime and even affect the next generation.
Wasting Number of under-fives falling below minus 2 standard deviations (moderate and severe) and minus 3 standard deviations (severe) from the median weight-for-height of the reference* population Children under 5 years of age in the surveyed population Wasting refers to a child who is too thin for his or her height. Wasting is the result of recent rapid weight loss or the failure to gain weight. A child who is moderately or severely wasted has an increased risk of death, but treatment is possible.
Overweight Number of under-fives above 2 standard deviations from the median weight-for-height of the reference* population Children under 5 years of age in the surveyed population Overweight refers to a child who is too heavy for his or her height. This form of malnutrition results from energy intakes from food and beverages that exceed children’s energy requirements. Overweight increases the risk of diet-related noncommunicable diseases later in life.

*The reference population is based on the WHO Child Growth Standards, 2006

Please note that some children can suffer from more than one form of malnutrition – such as stunting and overweight or stunting and wasting. There are currently no joint global or regional estimates for these combined conditions, but UNICEF has a country-level dataset with country level estimates, where re-analysis was possible.

GROWTH STANDARD (REFERENCE POPULATION)

Prevalence of stunting, wasting and overweight among children under 5 is estimated by comparing actual measurements to an international standard reference population. In April 2006, the World Health Organization (WHO) released the WHO Child Growth Standards to replace the widely used National Center for Health Statistics (NCHS)/WHO reference population, which was based on a limited sample of children from the United States of America. The new standards are the result of an intensive study project involving more than 8,000 children from Brazil, Ghana, India, Norway, Oman and the United States. Overcoming the technical and biological drawbacks of the old reference population, the new standards confirm that children born anywhere in the world and given the optimum start in life have the potential to reach the same range of height and weight. It follows that differences in children’s growth to age 5 are more influenced by nutrition, feeding practices, environment and health care than by genetics or ethnicity.

The new standards should be used in future assessments of child nutritional status. It should be noted that because of the differences between the old reference population and the new standards, prevalence estimates of child anthropometry indicators based on these two references are not readily comparable. It is essential that all estimates are based on the same reference population (preferably the new standards) when conducting trend analyses.

ADJUSTING COUNTRY-LEVEL ESTIMATES

Before conducting trend analyses of child nutritional status, it is important to ensure that estimates from various data sources are comparable over time. For example, household surveys in some countries in the early 1990s only collected child anthropometry information among children up to 47 months of age – or even up to only 35 months of age. Prevalence estimates based on such data only referred to children under 4 or under 3 years of age and are not comparable to prevalence estimates based on data collected from children up to 59 months of age. Some age adjustment needs to be applied to make these estimates based on non-standard age groups comparable to those based on the standard age range. For more information about age adjustment, please click here to read a technical note. In addition, prevalence estimates need to be calculated according to the same reference population. Those calculated according to the WHO Child Growth Standards are not comparable to those calculated according to the NCHS/WHO reference population. For more information about the difference between the two references and its implications, please click here to read a series of questions and answers.

ASSIGNING YEARS TO SURVEYS

When data collection begins in one calendar year and continues into the next, the survey year assigned is the one in which most of the fieldwork took place. For example, if a survey was conducted between 1 September 2009 and 28 February 2010, the year 2009 would be assigned, since the majority of data collection took place in that year (i.e., four months in 2009 versus two months in 2010). This method has been used since the 2013 edition (prior to that, the latter year was used by default – e.g., 2010 in the example above).

FINAL REPORTS ONLY

As of the 2014 edition, the country-level dataset used to generate the global and regional joint malnutrition estimates is based only on final survey results. Preliminary survey results are no longer included in the dataset since the data are sometimes retracted or change significantly when the final version is released.

ESTIMATING COUNTRY-LEVEL PROGRESS

Country-level progress in reducing undernutrition prevalence is evaluated by calculating the average annual rate of reduction (AARR) and comparing this to the AARR needed in order to achieve targets. For more information about how to calculate country-level AARR, please click here to read a technical note.  A Nutrition Targets Tracking Tool which provides AARR levels for different scenarios is also available to investigate progress towards the 2025 WHA nutrition targets for each country.

ESTIMATING REGIONAL TRENDS BY MULTILEVEL MODELLING

Estimation of regional and global trends is based on a multilevel modelling method (see de Onis et al. in JAMA, 2004). For the most recent trend analysis, a total of 837 data points from 150 countries over the period 1983 to 2017 were included in the model. This set of trend data points was jointly reviewed by UNICEF, WHO and the World Bank Group in January 2018 to ensure that it is nationally representative of under-five children, processed using standard algorithms and comparable vertically and horizontally. Global and regional trend modelling and graphing were carried out using SAS (the country-level data set and analysis code are available on request).

Model-based trend analysis of underweight prevalence (percentage), by region

How to read this chart:

Each circle represents a prevalence estimate from a country for one survey. The size of the circle is proportional to the under-five population in that country for the average of all survey years. The solid line indicates the regional trend as modelled on all the available data points in the region.

OTHER NOTES ON JOINT MALNUTRITION ESTIMATES

1. Explanation as to why trends are shown for stunting and overweight but only most current estimate for wasting and severe wasting: Prevalence estimates for stunting and overweight are relatively stable over the course of a calendar year. It is therefore possible to track global and regional changes in these two conditions over time. Wasting and severe wasting are acute conditions that can change frequently and rapidly over the course of a calendar year. This makes it difficult to generate reliable trends over time with the input data available, and as such, this report provides only the most recent global and regional estimates (2017 for the JME 2018 edition).

The joint global and regional estimates that make up the UNICEF/ WHO/World Bank Group Joint Child Malnutrition Estimates have been generated using a country-level dataset which is mainly comprised of estimates from nationally representative household surveys. These data are collected infrequently (every 3 to 5 years in most countries) and measure malnutrition at one point in time (e.g. during one or several months of field work), making it difficult to capture the rapid fluctuations in wasting that can occur over the course of a given year. Incidence data (i.e. the number of new cases that occur during the calendar year) would allow for better tracking of changes over time; however, these data currently do not exist.

 2. Footnotes on population coverage
As started in the 2014 edition, a separate exercise was conducted to assess population coverage. This was important in order to alert the reader, via footnotes, to instances where the data should be interpreted with caution due to low population coverage (defined as less than 50 per cent). A conservative method was applied looking at available data within mutually exclusive five-year periods around the projected years. Population coverage was calculated as:

 3. Prevalence thresholds for wasting, overweight and stunting in children under 5 years

New thresholds, presented in the table below, were established through the WHO-UNICEF Technical Advisory Group on Nutrition Monitoring (TEAM)2 and have been used for development of prevalence-based maps. The thresholds were developed in relation to standard deviations (SD) of the normative WHO Child Growth Standards. The international definition of ‘normal’ (two SD from the WHO standards median) defines the first threshold, which includes 2.3% of the area under the normalized distribution. Multipliers of this “very low” level (rounded to 2.5%) set the basis to establish subsequent thresholds.

Prevalence thresholds (%) for severity of malnutrition among children under 5 years

Labels Prevalence thresholds (%) for:
Wasting Overweight Stunting
Very low <2.5 <2.5 <2.5
Low 2.5 – <5 2.5 – <5 2.5 – <10
Medium 5 – <10 5 – <10 10 – <20
High 10 – <15 10 – <15 20 – <30
Very high ≥15 ≥15 ≥30

de Onis, Mercedes et al. (2018) Prevalence thresholds for wasting, overweight and stunting in children under 5 years. (Manuscript submitted for publication.)