Since 2011, World Hunger Day has celebrated solutions for hunger and poverty. Yet hunger is on the rise, and 821 million people are undernourished, facing chronic food deprivation. This contributes to malnutrition — and poor mothers and children in low- and middle-income countries are hardest hit.

Malnutrition undercuts healthy development, often irreversibly in children, leaving an estimated 149 million children worldwide affected by stunted growth.

But solutions exist. In fact, many evidence-based solutions, which could improve nutrition policies, are inexpensive. And the economic benefits of improving nutrition policies would be immense — malnutrition costs the global economy up to $3.5 trillion every year, a result of productivity losses and health-care costs.

Recognizing the need to address maternal and child malnutrition, the United Nations launched the “Scaling Up Nutrition” movement in 2010. The international initiative invites countries to sign on and introduce improved policies, among other things. Yet national nutrition policies remain inadequate in many low- and middle-income countries.

So why don’t governments simply prioritize nutrition and introduce better policies? Technical experts such as nutritionists, doctors and epidemiologists usually talk about the need for more scientific research to inform policies. But here’s the thing — politics also matters. Exclusively focusing on the science overlooks the impact of hard-nosed political calculations.

Politics can affect the introduction of better nutrition policies in three ways:

1. Competing issues can push nutrition off the agenda

Governments might use social policies to garner political support. But to really drum up support, these policies have to be visible and have an immediate impact.

Politicians have promised social policies — such as food programs, conditional cash transfers or health services — to get voted into office. When they introduce policies that distribute food, give out cash or provide health care, voters see what they’re getting and immediately know how they’ll benefit.

If implemented well, these policies could indirectly improve nutrition. But they are different from the nutrition policies that experts recommend, which are sometimes called “nutrition-specific” policies.

Many of these nutrition policies address micronutrient deficiencies, which affect more than 2 billion people. Micronutrient deficiencies stem from an inadequate intake of vitamins and minerals such as iodine, iron and vitamin A.

Here’s a good example: Iodine deficiencies can cause serious physical and mental impairments. That’s why an important nutrition policy is the fortification of edible salt with iodine. Everyone eats salt, and iodized salt adds this micronutrient to our diets.

But have you ever heard of a politician campaigning on a platform that includes the introduction of a salt iodization policy? Politicians campaign on — and prioritize — visible issues, particularly those with immediate results. For most people, the link between iodine and health is not visible. And improving iodine intake doesn’t have the same, immediate impact as rice on the table, cash in the bank or access to health care.

Competing issues can push nutrition off the agenda because politicians find it hard to use nutrition policies for political gain.

2. Governments have little incentive to prioritize poor mothers and children

Governments might express concern for poor mothers and children, but when resources decline and other pressures mount, they are more likely to prioritize groups whose support they need for political survival.

When governments introduce social policies for the poor, they tend to focus on blue-collar workers employed in the formal labor market. The working poor can organize and place pressure on governments through strikes and protests, creating an incentive for governments to prioritize their needs.

However, women make up a disproportionate percentage of workers in the informal labor market — they take jobs as domestic helpers, street vendors or subsistence farmers. Informal sector workers are often poorly paid and lack opportunities to organize, reducing their political influence.

As a result, policies that support informal workers and their dependents — such as improved nutrition policies — have a hard time becoming a government priority.

3. Poor mothers and children may lack a clear incentive to mobilize for change

Let’s say poor women and children did organize to exert political pressure. Would they demand better policies to address micronutrient deficiencies? Probably not. The “invisible” nature of micronutrient malnutrition is why it’s often called “hidden hunger.”

Those with micronutrient deficiencies typically don’t know their diets are insufficient. They eat a lot of starchy staples such as rice or potatoes. This gives them enough calories to stave off hunger, but not the vitamins and minerals they need.

As micronutrient malnutrition only becomes visible when the problem is severe, deficiencies can cause physical and intellectual impairments but remain undetected. Understandably, poor mothers and children are less likely to mobilize for change. Without this pressure, governments can place a lower priority on malnutrition.

What can be done?

All too often, effective solutions fail to reach the poor because of misaligned political incentives. The global nutrition community, however, has traditionally focused on generating scientific evidence to combat malnutrition. To be sure, this is important research, and it should continue. But evidence does not automatically make its way into policy.

A critical area of research is on the impact of international initiatives on policy change — and when and how governments introduce better policies for poor women and children. To date, 60 countries have signed on to the Scaling Up Nutrition movement. What remains unknown is whether the initiative has been effective in eliciting policy change.

My research shows that international initiatives can improve social policies — but under certain conditions. Understanding these conditions, so that governments improve policies for those who need it the most, is an important step in improving social welfare. Stay tuned for my book project, where I look at the impact of the Scaling Up Nutrition initiative on policies for poor women and children.

Carmen Jacqueline Ho (@carmenjho_) is an assistant professor in the Department of Political Science and Institute of Development Studies at the University of Guelph. She held a Fulbright Award at Harvard University with the Takemi Program in International Health and Weatherhead Research Cluster on Comparative Inequality and Inclusion.