Child Malnutrition
Stunting has declined steadily since 2000 – but faster progress is needed to reach the 2030 target. Wasting persists at alarming rates and overweight will require a reversal in trajectory if the 2030 target is to be achieved
Nearly half of all deaths in children under 5 are attributable to undernutrition; 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 2023 edition of the UNICEF-WHO-World Bank Group Joint Malnutrition Estimates shows that stunting prevalence has been declining since the year 2000, more than one in five – 148.1 million children under 5 –were stunted in 2022, and at least 45.0 million suffered from wasting at any given point of time in the year. Meanwhile, the number of children under 5 affected by overweight worldwide has increased from 33.0 million in 2000 to 37.0 million in 2022.
Measures of child malnutrition are used to track development progress. Estimates of child malnutrition will help determine whether the world is on track to achieve the Sustainable Development Goals – particularly, target 2.2, to “end all forms of malnutrition by 2030”, which falls under goal 2 to “end hunger, achieve food security and improved nutrition, and promote sustainable agriculture”.
Stunting
In 2022, three regions had very high stunting prevalence, with approximately one third of children affected. On the other hand, two regions Europe and Central Asia and Northern America, had low stunting prevalence. However, vast disparities within regions can exist. In Latin America and the Caribbean, for example, despite the 11.5 per cent regional prevalence, some individual countries are faced with high, and very high stunting prevalence, while others have very low prevalence below 2.5 per cent. Chronic undernutrition in Latin America and the Caribbean can vary widely between neighboring countries: In one country less than 1 in 8 are affected, while more than 2 in 5 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 2022, 22.3 per cent, or more than one in five children under age 5 worldwide had stunted growth. That said, overall trends are positive. Between 2000 and 2022, stunting prevalence globally declined from 33.0 per cent to 22.3 per cent, and the number of children affected fell from 204.2 million to 148.1 million. In 2022, nearly two out of five children with stunting lived in South Asia while another two out of five lived in sub-Saharan Africa.
Wasting and severe wasting
Overweight
Middle East and North Africa had the highest overweight prevalence in 2022 with 10.3 per cent affected, followed by Latin America and Caribbean at 8.6%. The lowest overweight prevalence in 2022 was seen in South Asia at 2.7 per cent followed by West and Central Africa at 3.1 per cent. East Asia and the Pacific had the highest number of overweight children in 2022 with nearly 11 million affected, followed by Middle East and North Africa with an estimated 5.0 million overweight children under 5 years. Overall, these two regions account for just over 2 out of 5 children affected by overweight in the world.
References
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.
United Nations Children’s Fund (UNICEF), World Health Organization (WHO), International Bank for Reconstruction and Development/The World Bank. Levels and trends in child malnutrition: UNICEF / WHO / World Bank Group Joint Child Malnutrition Estimates: Key findings of the 2023 edition. New York: UNICEF and WHO; 2023.
Nutritional status
Malnutrition data
Build and download your own customisable dataset
Resources
Notes on the data
Indicators
|
Indicator name |
Definition |
||
|---|---|---|---|
|
Numerator |
Denominator |
Plain language definition |
|
| Stunting | Number of children under five years of age with height for age z-scores below minus 2 standard deviations (moderate and severe) and minus 3 standard deviations (severe) from the median height-for-age of the reference* population | Number of children under five 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 children under five years of age with weight for height z-scores minus 2 standard deviations (moderate and severe) and minus 3 standard deviations (severe) from the median weight-for-height of the reference* population | Number of children under five 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 with moderate or severe wasting has an increased risk of death, but treatment is possible. |
| Overweight | Number of children under five years of age with weight for height z-scores above 2 standard deviations from the median weight-for-height of the reference* population | Number of children under five 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 provides a country-level dataset with country level estimates, where re-analysis was possible.
WHO Child Growth Standards 2006 (reference population)
The prevalence of children under 5 affected by stunting, wasting and overweight 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, which replaced the 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 WHO 2006 standards were the result of research 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 WHO 2006 standards confirmed 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. The research demonstrated that differences in children’s growth until the age of 5 years are more influenced by nutrition, feeding practices, environment and health care than by genetics or ethnicity.
Explanation why national trends are shown for stunting and overweight but only most current national estimate are presented for wasting and severe wasting:
Wasting (or acute malnutrition) is a relatively short-term condition but is a predictor of child mortality and increased susceptibility to stunting, as well as future episodes of wasting. Although it is rare, an individual child can be affected by wasting more than once in a calendar year.
In countries where populations have stable access to healthy diets, health care, safely managed water and sanitation and basic hygiene facilities, there is little to no seasonal variation in wasting. Studies reveal that in countries with high burdens of wasting, the prevalence of wasting can double between cool and hot/rainy seasons.[1] [2] This is confirmed by most of the longitudinal cohort data from 21 lower- and middle-income countries.[3]
The JME prevalence of wasting and severe wasting are based on national level estimates mostly from cross-sectional surveys. These surveys can be collected over several seasons or even years. Due to the complexity of planning and implementing national surveys, most data sources included in the JME database are not able to address the risk of seasonal bias. The prevalence of wasting is representative of the time period of data collection and does not reflect the number of cumulative cases (incidence) of wasting occurring over a defined time period, like a month or a year.[4]
The lack of incidence data for wasting and severe wasting is a main reason why the JME does not present annual national trends for acute malnutrition. Since the prevalence data are collected infrequently (every 3 to 5 years) in most countries, it is not possible to capture the fluctuations in wasting over the course of a year or to account for variations by season across survey years. In contrast, stunting and overweight are relatively stable or have a low prevalence over the course of the calendar year, allowing the calculation of trends in these two conditions over time with prevalence data.
For the reasons above, the calculation of the number of children affected by wasting or severe wasting cannot accurately calculated with the equation of population times prevalence. Therefore, the JME reported global estimates of the number of children under 5 affected by wasting and severe wasting likely underestimate the true number of children affected and in need of treatment each year.
For more information on the JME standard methodology, please see
https://data.unicef.org/resources/jme-standard-methodology/
Footnotes
[1] Helen Keller International / Institute of Public Health Nutrition (2006a). Trends in child malnutrition, 1990 to 2005: Declining rates at national level mask inter-regional and socioeconomic differences. Nutrition Surveillance Project Bulletin No. 19. Dhaka: Helen Keller International/Bangladesh.
[2] Johnston R, Dhamija G, Kapoor M, Agrawal PK, Wagt A. Methods for assessing seasonal and annual trends in wasting in Indian surveys (NFHS-3, 4, RSOC & CNNS). PLoS One. 2021 Nov 22;16(11):e0260301. doi: 10.1371/journal.pone.0260301.
[3] Mertens, A., Benjamin-Chung, J., Colford, J.M. et al. Child wasting and concurrent stunting in low- and middle-income countries. Nature 621, 558–567 (2023). https://doi.org/10.1038/s41586-023-06480-z
[4] Isanaka S, Andersen CT, Cousens S, et al Improving estimates of the burden of severe wasting: analysis of secondary prevalence and incidence data from 352 sites BMJ Global Health 2021;6:e004342.