A recent study published in Nature Food suggests that global assessments of food insecurity may significantly underestimate the number of people facing hunger. The research examined the United Nations' Integrated Food Security Phase Classification (IPC) system, which is used by aid organizations to determine where humanitarian assistance is most urgently needed.
The IPC, established in 2004 as a consortium of 21 partner organizations, evaluates food security in about 30 countries and guides the allocation of more than $6 billion in humanitarian aid each year. Its analysis relies on a range of data, including food prices, weather patterns, and dietary quality, to classify regions according to levels of hunger from minimal to famine.
"This matters because these metrics are used to trigger funding for emergency relief," said Kathy Baylis, co-author and professor at UC Santa Barbara's Department of Geography.
In 2023, approximately 765 million people worldwide did not have enough food to meet basic needs. Nearly one-third faced acute food insecurity that threatened their lives.
The new study was conducted by researchers from several institutions including UC Santa Barbara, University of Illinois Urbana-Champaign (UIUC), and University of Texas at Austin. Lead author Hope Michelson, a professor at UIUC’s Department of Agricultural and Consumer Economics, noted the challenge in evaluating such systems: "In a sense this means that if they're correct and effective, they're always wrong."
The research team interviewed around 20 humanitarian agencies using the IPC system and found that many users believed the IPC overstates crises. However, after analyzing nearly 10,000 assessments covering 917 million individuals across 33 countries between 2017 and 2023—totaling about 2.8 billion person observations—they discovered otherwise.
Their analysis showed evidence that committees often classified areas just below the critical threshold for urgent aid (20% population hungry), especially when data were conflicting or uncertain. As Baylis explained: "So if you see lots and lots of places that have 19% of the population being hungry, and very few showing 20 or 21% hunger, that could suggest that the committees are trying to be conservative."
Comparing their own estimates with those from IPC working groups revealed a significant gap: "They identified 293.1 million people in phase 3 or higher, compared to IPC's assessments of 226.9 million people." This indicates about one in five people needing urgent help may go uncounted.
"The food security indicators that are available to the IPC analysis teams don't always agree with each other," Michelson stated. "The working groups will have different information about the same region over the same amount of time. And we found that they tend to take a more conservative approach in their analysis, especially when indicators are contradictory."
"We think that the committees are worried about the accusation that they overestimate the numbers, so, when in doubt, they undercount," Baylis added.
Despite these findings, researchers emphasized that the IPC remains an essential tool for measuring global hunger but suggested improvements such as refining data collection methods and possibly incorporating machine learning into analyses.
"There already are huge shortfalls in aid for hunger and famine," Baylis said, "and our work shows that the need is even greater than we thought."
Michelson agreed: "understanding that the current figures are likely to underestimate the actual global population of food-insecure people further underscores the scale and the scope of need, and the importance of allocating more resources to alleviating hunger worldwide."
