Researchers say malnutrition in infants ‘far bigger problem than previously recognized’, amid ongoing cuts

Over 10 million infants under six months old may currently be underweight, according to a new analysis of data collected across low- and middle-income countries (LMICs).

The study, published in BMJ Global Health and led by researchers at the London School of Hygiene & Tropical Medicine (LSHTM) and the Emergency Nutrition Network (ENN), estimated the burden of malnutrition among infants using survey data collected across 56 countries.

The study analyzed data on over 50,000 children under six months gathered through Demographic and Health Surveys (DHS) collected across West & Central Africa, Eastern & Central Africa, Latin America & the Caribbean, East Asia & the Pacific, Eastern Europe and Central Asia, the Middle East and North Africa, and South Asia.

The DHS are nationally-representative household surveys conducted across LMICs every five years or so, and include data on the current weight, height (or length), age and weight at birth for infants. Once collected, the data is made available for researchers worldwide to analyze.

In the study, infants with a low weight-for-age score (WAZ) were classed as underweight, infants with a low weight-for-length score (WLZ) were classed as too thin, showing signs of wasting, and infants with a low length-for-age score (LAZ) were classed as too small in length for their age. These are all globally-recognized indicators of malnutrition.

Across all of the countries measured, 17.4% of infants under the age of six months were clinically underweight, 15.5% showed signs of wasting, 19.9% were small in length for their age (stunted) and 15% were underweight at birth.

When applied to the current population across all LMICs globally, these estimates 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 lead author of the study, said, “Malnutrition is responsible for around 45% of child deaths globally. In 2022, undernutrition accounted for a total of 2.3 million child deaths, which equates to over 6000 deaths each and every day.

“For context, these are the numbers who would die if 18 commercial airliners were to crash every day. It’s wrong that some tragedies, such as infant and child malnutrition, continue to be largely silent, forgotten and ignored.

“Our study also shows how crucial national datasets like the DHS are for global health research. The DHS, which provides openly accessible data for researchers like ourselves to analyze, has currently been paused and if not restarted soon, future numbers will not be tracked. DHS surveys help to see a hidden problem. Without them, we cannot track the problem and progress and hold each other to account.

“Our findings show that malnutrition in infants under six months old is a far bigger problem than previously recognized. We hence strongly support organizations like WHO and UNICEF as well as many governments worldwide seeking to improve treatments for this vulnerable group.”

Malnutrition in infants under six months is a major global health problem, and can be devastating for families and communities. These infants are at high risk of death, illness and poor development in the short term, and have a higher risk of non-communicable disease (including heart disease) in later life. Some studies have also shown that the long-term effects of malnutrition can be intergenerational.

Marie McGrath, Technical Director at the Emergency Nutrition Network (ENN) and Ph.D. student at LSHTM, and co-author of the study, said, “Big numbers sometimes dehumanize. Behind every one of the surveys we analyzed is a personal tragedy. There is a baby suffering and devastated families experiencing daily worry and loss. As a society, how can we be complacent and shy away from babies facing increased risk of death in their first months of life?

“The good news is that health services are primed to act. Growth monitoring—that helps identify underweight babies—is recommended in national health services worldwide. Babies born too early or too small need close follow-up and the first vaccination at six weeks is a critical time to measure.

“National health services need direct investment in equipment, training and mentoring on identifying and managing these cases. Let’s reinvest, not reinvent. Using one indicator—underweight—is consistent across newborn, malnutrition and health communities and simpler for health workers. Let’s work together to assess, appraise and act.”

As this is an observational study using survey data, it only looks at a snapshot of the situation in each country. The team believe that the true number of infants experiencing malnutrition may be greater, as data on other indicators of malnutrition such as mid-upper arm circumference or swelling were not available and some surveys were up to 10 years old.

They also suggest that underweight scores (low weight-for-age) may be a better indicator of malnutrition compared to typically used low weight-for-length, due to higher data quality and stronger links to health risks.

This supports the recently updated World Health Organization malnutrition guidelines, which now include underweight as a criteria for enrollment in supportive nutrition and health care for infants under six months.