Women and their children, who fled from attacks by rebel groups, work in a field farmed with the help of the Food and Agriculture Organization in Tshikapa in the Kasai Region of Congo on July 27. (Junior D. Kannah/AFP/Getty Images)

Today marks the eighth annual Africa Day for Food and Nutrition Security, which aims to raise awareness of chronic hunger and malnutrition and to encourage collaboration between national, regional and international actors to achieve food security. Although most African countries have made progress over the past decade, the food-security situation remains severe. Here’s what you need to know.

1. Many Africans are food insecure, despite marked improvements in nutrition over the past two decades.

The good news is that undernourishment in sub-Saharan Africa has declined from 28.1 percent in 2000 to 20.8 percent in 2015. With better nutrition, fewer children suffer from stunting, defined by the World Health Organization as growth impaired so much that height-for-age falls two standard deviations below the international average. The percentage of children stunted in sub-Saharan Africa decreased from 49 percent in 1990 to 35 percent in 2016. Despite this overall shift, population growth has meant that the absolute number of stunted children has increased in sub-Saharan Africa from 45 million in 1990 to 57 million in 2016.

Sub-Saharan Africa is the region most affected by undernourishment. The Food and Agriculture Organization (FAO) measures undernourishment as the number of people older than 15 who are “hungry but did not eat or went without eating for a whole day because there was not enough money or other resources for food.” Just more than a fifth of sub-Saharan Africans were undernourished in 2016, but the prevalence of undernourishment varies across the continent. In 2015, undernourishment was particularly high in the Central African Republic (48 percent), Zambia (48 percent) and Namibia (42 percent). Children and women are particularly at risk.

2. There is a large gap between global initiatives governments sign onto and the reality on the ground.

Our research shows that a crucial challenge to achieving food security in Africa is the proliferation of policies that are only partly implemented or are not well connected with the reality on the ground.

Most African countries have adopted international agendas such as the Sustainable Development Goals and regional policies such as the Comprehensive Africa Agriculture Development Program (CAADP) in addition to their national strategies. These programs aim to end hunger through increasing agricultural productivity and building resilient economies. One way CAADP does this is requiring signatories to commit to allocating 10 percent of government expenditure to food and nutrition security and broader agriculture programming.

On-the-ground stakeholders now call for governments to focus on following through with implementing these policies — and rightfully so. The analysis of more than 40 CAADP countries shows that those most committed to implementing CAADP objectives are more likely to see success in transforming agriculture and improving food security.

3. Environmental shocks and other vulnerabilities threaten progress.

Case studies from the Ending Rural Hunger project show that environmental shocks and adverse macroeconomic conditions threaten food and nutrition security. In addition to fighting food insecurity, Ethiopia has faced recurrent drought, Nigeria has had to address oil price shocks and insurgencies, and Ghana has faced difficult macroeconomic conditions such as inflation. Similarly, although Senegal has made progress toward rice self-sufficiency, the country still imports almost half of its cereal requirement, exposing the country to global food price shocks. Governments hoping to achieve food security have to plan for these shocks.

Of course, there are success stories, with countries having implemented school feeding interventions, conditional cash transfers and livelihood support for the populations most affected by such shocks. One way to plan for shocks is to build resiliency in food-insecure areas. For example, the Productive Safety Net Program in Ethiopia provides poor, rural populations with annual cash transfers and agricultural inputs to make them more resistant to shocks. A recent study shows that the program reduced the length of the hunger season by almost one-third.

4. Dependence on foreign aid and budget inefficiencies threaten sustainability of food-security interventions.

In Ghana, external resources heavily support a number of ongoing social protection and agricultural growth programs. In Uganda, foreign aid overshadows government investment in agriculture. Dwindling donor support raises concerns about the sustainability of food security interventions.

Even with sufficient resources for food-security interventions, inefficiency in allocation can act as a bottleneck for successful programming. Senegal is a great example. While it has the fourth-largest public budget for agriculture, certain areas and populations have experienced greater vulnerability to food insecurity. One potential explanation is Senegal’s relatively poor investment in infrastructure. Research shows that areas with sufficient infrastructure have greater agricultural productivity and suggests that more efficient budget allocations — namely to support infrastructure — would enhance food-security initiatives.

Landry Signé is a David M. Rubenstein fellow in the Global Economy and Development Program and Africa Growth Initiative at the Brookings Institution, distinguished fellow at Stanford University’s Center for African Studies, professor and senior adviser to the chancellor on international affairs at the University of Alaska at Anchorage, Andrew Carnegie fellow, World Economic Forum Young Global Leader, and chairman of the Global Network for Africa’s Prosperity. He is the author of “Innovating Development Strategies in Africa: The Role of International, Regional and National Actors.” Follow him on Twitter @landrysigne.

Eyerusalem Siba is a research fellow at the Africa Growth Initiative in the Global Economy and Development Program at the Brookings Institution. She oversees a multicountry assessment on ending rural hunger in Ethiopia, Ghana, Nigeria, Senegal, Tanzania and Uganda. Follow her on Twitter @EsibaSiba.