2025-05-30T17:56:04Z

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A recent analysis conducted by researchers from the London School of Hygiene & Tropical Medicine (LSHTM) and the Emergency Nutrition Network (ENN) has uncovered a troubling reality: over 10 million infants under the age of six months may currently be experiencing underweight issues across low- and middle-income countries (LMICs). This significant finding was published in the esteemed journal BMJ Global Health, underscoring the urgent need to address the crisis of malnutrition affecting infants globally.

The study's researchers analyzed data collected from more than 50,000 children under six months of age through Demographic and Health Surveys (DHS) conducted across 56 countries spanning various regions, including West and Central Africa, Eastern and Central Africa, Latin America and the Caribbean, East Asia and the Pacific, Eastern Europe and Central Asia, the Middle East and North Africa, as well as South Asia.

The DHS are nationally representative household surveys that are carried out approximately every five years in LMICs. These surveys gather critical data on the current weight, height (or length), age, and birth weight of infants. Once this valuable information is compiled, it becomes available for researchers around the world, enabling them to analyze malnutrition trends and issues.

In the study, infants were categorized based on various weight and length measurements. Those with a low weight-for-age z-score (WAZ) were classified as underweight, while infants demonstrating a low weight-for-length z-score (WLZ) were identified as too thin or wasted. Additionally, infants with a low length-for-age z-score (LAZ) were denoted as too small for their age. These classifications are internationally recognized as indicators of malnutrition and are critical for understanding the nutritional status of children.

The results of the study revealed alarming statistics: 17.4% of infants under six months were found to be clinically underweight, 15.5% exhibited signs of wasting, 19.9% were stunted in length for their age, and 15% had been born with low birth weight. When extrapolated to the current population of infants in all LMICs globally, these figures suggest that approximately 10.3 million infants are underweight, 9.2 million are wasted, 11.8 million are stunted, and 8.9 million have been born with a low birth weight.

Marko Kerac, Clinical Associate Professor at LSHTM and the lead author of the study, shed light on the severity of the situation, stating, "Malnutrition is responsible for around 45% of child deaths globally. In 2022 alone, undernutrition contributed to a staggering total of 2.3 million child deaths, equating to over 6,000 fatalities each day. This represents a shocking reality where the equivalent of 18 commercial airliners crashing daily goes largely unnoticed. It is deeply troubling that such tragedies as infant and child malnutrition continue to be largely silent, forgotten, and ignored within our society."

Kerac emphasized the crucial role of national datasets like the DHS in global health research, stating, "The DHS, providing publicly accessible data for researchers like ourselves, has currently been paused. If this data collection is not restarted soon, we will lose the ability to track future numbers. These surveys are essential for identifying hidden problems in public health. Without them, we cannot monitor issues effectively and hold ourselves accountable for progress toward solutions."

The findings from this research highlight that malnutrition among infants under six months is a far more extensive problem than previously acknowledged. The study reinforces the importance of organizations such as the World Health Organization (WHO) and UNICEF, as well as various governments worldwide, in their efforts to improve the treatment and health outcomes for this vulnerable demographic.

Malnutrition in infants under six months poses a significant global health threat, with devastating consequences for not only the infants themselves but also for their families and communities. Infants facing malnutrition are at a heightened risk of death, illness, and poor developmental outcomes in the short term. Furthermore, they are more likely to suffer from non-communicable diseases, including heart disease, later in life. Research has even suggested that the long-term impacts of malnutrition can transcend generations, affecting not just the infant but future offspring as well.

Marie McGrath, Technical Director at the ENN and a Ph.D. student at LSHTM, co-authored the study and commented on the human impact of these statistics. She stated, "Big numbers can sometimes dehumanize the issue at hand. Behind every statistic lies a personal tragedy—there is a baby suffering and families grappling with daily worry and loss. As a society, we must ask ourselves how we can remain complacent while infants face elevated risks of mortality in their first months of life?"

Fortunately, there is a silver lining. McGrath highlighted that health services are well-positioned to make a difference. She noted, "Growth monitoring, which helps identify underweight babies, is a standard recommendation in national health services across the globe. Infants born too early or too small require close monitoring, and the first vaccination at six weeks is a critical opportunity to measure their growth and health status. National health services must prioritize direct investments in the necessary equipment, training, and mentorship to effectively identify and manage these cases. We should aim to reinvest in proven strategies rather than reinvent the wheel. By using underweight as a single indicator, we can create a consistent approach across newborn health, malnutrition, and overall health communities, making it simpler for health workers to act on these issues."

It is important to note that this study is observational in nature, relying on survey data that provides only a snapshot of the malnutrition situation in each country. The research team believes that the actual number of infants experiencing malnutrition could be even greater. This is due to the lack of data on other malnutrition indicators, such as mid-upper arm circumference or swelling, as well as the fact that some of the surveys utilized in the analysis are over a decade old.

Moreover, the researchers propose that underweight scores (low weight-for-age) may serve as a more reliable indicator of malnutrition compared to the commonly used weight-for-length measurements. This assertion is based on the higher data quality associated with weight-for-age metrics and their stronger links to health risks.

This perspective supports recent updates to the World Health Organization's guidelines on malnutrition, which now include underweight as a criterion for enrolling infants under six months in supportive nutrition and healthcare programs. The necessity for updated and accurate data is paramount in the fight against malnutrition, ensuring that interventions can be effectively implemented to protect the health and future of infants worldwide.

For more information on this important study, readers can refer to the research article by Marko Kerac et al., titled "Malnutrition in infants aged under 6 months: prevalence and anthropometric assessment – analysis of 56 low- and middle-income country DHS datasets," published in BMJ Global Health (2025). DOI: 10.1136/bmjgh-2024-016121.