Rethinking poverty measures through the lens of healthy diets

When we hear about global poverty, the conversation often revolves around the World Bank’s international poverty line, which is currently set at $2.15 per day. What this benchmark tells us is that roughly 712 million people live in “extreme poverty.” But that figure only measures the ability to afford enough calories to survive. It doesn’t account for whether those calories come from nutritious, health-sustaining food.

A study by researchers Jonas Stehl and Sebastian Vollmer from the University of Goettingen and Lutz Depenbusch from MISEREOR, a German development NGO, argues that this standard dramatically underestimates the true scale of poverty. Their paper, published in Food Policy, suggests that when we factor in the cost of a healthy diet, not just enough calories to survive but enough nutrients to thrive, the global poverty picture looks radically different.

Long story short, between 2.3 and 2.9 billion people (about one in three humans on Earth) cannot afford a healthy diet.

Think of the international poverty line as a budget diet plan designed to keep someone alive on the bare minimum. It’s like saying, “As long as you can buy a sack of rice and some cooking oil, you’re not poor.” But as anyone who has lived on instant noodles for a week knows, surviving is not the same as living healthily. A healthy diet requires a balance of proteins, vitamins, and minerals, things you don’t get from the cheapest available calories. The researchers point out that relying on current poverty lines ignores the very basics of human well-being: preventing disease, supporting child development, and maintaining long-term health.

Globally, more than two billion people already suffer from “hidden hunger”, a lack of essential micronutrients like iron and vitamin A. And poor diets are now the leading risk factor for chronic illnesses such as diabetes, heart disease, and cancer. In other words, the way we define poverty today overlooks one of its biggest consequences: poor health.

To tackle this blind spot, the authors propose a new measure they call the Healthy Diet Poverty Line (HPL). Instead of asking, “Can people afford enough calories?” they ask, “Can people afford the least-cost diet that meets modern nutrition guidelines?”

Here’s how they did it. They used the World Bank food price data from around the world to calculate the cheapest possible basket of foods that still meets national dietary recommendations. They factored in non-food essentials like housing, clothing, education, and healthcare. Then, they adjusted for different age and gender needs (since, for example, a child requires fewer calories than an adult man).

While the World Bank’s measure counts 654 million people in extreme poverty, the new nutrition-based lines identify 2.3 to 2.9 billion people as poor, which is up to four times more than conventional estimates. And it’s not just a question of headcounts. The study estimates that the world’s poor are collectively short by $1.7 to $2.4 trillion per year, the amount of money it would take to lift everyone to the point where they could consistently afford a healthy diet.

Not surprisingly, the shortfall is most acute in developing countries in South Asia and Sub-Saharan Africa, home to hundreds of millions who can’t afford diverse diets. But the problem isn’t confined to low-income countries. The researchers show that even in richer nations, there are millions of people who, while not classified as “extremely poor,” still can’t afford balanced meals. In fact, applying the healthy diet poverty lines reveals significant hidden poverty in middle-income countries and even in parts of the so-called Global North.

This shift in perspective has huge implications. If one-third of the world’s population cannot afford healthy food, then our fight against poverty isn’t just about lifting people above a dollar figure—it’s about ensuring access to nutrition and dignity. And the economic stakes are enormous. Poor diets don’t just harm individuals; they drag down entire economies. Malnutrition and diet-related diseases cost the world trillions of dollars annually in healthcare bills, lost productivity, and stunted development. For instance, the global cost of diabetes alone is projected to reach $2.2 trillion by 2030. Compare that with the estimated $1.7 to $2.4 trillion annual gap needed to close the healthy diet poverty line, and the math is clear: investing in nutrition pays for itself many times over.

Rethinking the global poverty debate

The study makes a bold but simple point: our definition of poverty is outdated. The $2.15 poverty line may capture survival, but it misses what it means to live a healthy, fulfilling life. Poverty, the authors argue, should be measured not just in calories, but in nutrients, health, and social inclusion. This research also echoes a broader shift in development thinking. Measuring poverty by healthy diet affordability aligns with the vision of the UN’s Sustainable Development Goals (SDGs) of the “Zero Hunger” project, which aims not just to end starvation but to end all forms of malnutrition by 2030.

Numbers in the billions can feel abstract. But think of it this way. Imagine a mother in rural Malawi who has enough maize meal to feed her children but cannot afford vegetables, milk, or eggs; a garment worker in Bangladesh who earns just enough to keep rice and lentils on the table but never enough for fruit or fish. Or even a low-income family in the U.S. who technically earn more than \$2.15 a day but still rely on cheap processed foods because fresh produce and lean protein are unaffordable. By today’s official measures, none of these families might count as “poor.” But by the standard of a healthy diet, the standard that matters for human growth, development, and dignity, they clearly are.

If you want to learn more, the original article titled "Global poverty and the cost of a healthy diet" on Food Policy at https://doi.org/10.1016/j.foodpol.2025.102849