Closeup of a woman holding a chicken egg in her hands, while another egg sits on a stand waiting to be cooked.

Science has come a long way in determining what the human body requires to be “healthy.” While there are diverse opinions on the specifics, health experts agree that good nutrition plays a significant role in our well-being. What exactly defines “good” nutrition is where we sometimes enter into heated, though well-intentioned, debate.

Most of my career has centered around conducting research to inform public policies that prevent undernutrition and obesity, particularly for women and young children. It’s these key moments in the life cycle—a mother’s childbearing years and the first “1,000 days” starting from pregnancy through a child’s second birthday—that are most critical to the development of our brains and bodies.

This type of research is, unfortunately, still necessary to address a very daunting global challenge: According to the Food and Agriculture Organization of the United Nations, 821 million people around the world—or about 11 percent of the population—are chronically undernourished. About 151 million children under 5 are so undernourished that their growth has been stunted, potentially affecting their physical and cognitive development, their ability to fight off diseases, and their economic potential as they grow into adulthood. Research suggests that these effects may be irreversible.

In addition to promoting breastfeeding as the best practice to build nutrition in young children, my research has also led me to appreciate the important role that animal-source foods can play in crafting a well-balanced nutrition profile, particularly for children living in low- and middle-income countries.

For example, eggs may offer one of the most low-cost, high-return solutions to undernutrition in young children. A great source of protein, essential fatty acids, and choline, eggs also offer several unique immune properties in one affordable, efficient package. Through recent research I conducted with colleagues Lora Iannotti of Washington University and Christine Stewart of the University of California-Davis, we found that eggs reduced stunting in young children in Ecuador by an average of 47 percent. With a grant from the Bill & Melinda Gates Foundation, we’re currently working to replicate those findings in Malawi.

Expanding on that research, RTI recently conducted a study to examine the knowledge, beliefs, and practices related to consuming eggs during pregnancy in Kenya. Our study showed that egg consumption is low among pregnant women in Kenya and, while there are potential belief barriers, many see eggs as good for pregnant women.

The families in our study saw health workers as a trusted source of nutrition information, indicating that interpersonal communication from health workers could lead to an increase in consumption. Cost was also seen as a barrier to higher consumption. Agricultural interventions that promote policies and practices to increase productivity could increase availability and lower prices to help address the cost constraints.

Cow’s milk also holds great potential for reducing undernutrition. While milk consumption has declined in some higher-income countries over recent decades, it still holds significant nutritional promise for mothers and young children all over the world. Similar to eggs, cow’s milk was designed by nature to provide all of the vitamins and nutrients required for a calf’s development. When tolerated by the digestive system, consumption of milk by young children is recommended to provide nutrients that can help with child growth and brain development.

In Rwanda, my colleague Valerie Flax is working with the International Livestock Research Institute and the University of Rwanda to determine the efficacy of a nutrition education intervention aimed at increasing consumption of animal-source foods, especially cow’s milk, by 1-to-2-year-old children in poor households that have received a cow through a government program. The intervention promotes the continuation of breastfeeding and feeding a variety of foods in addition to giving the child cow’s milk. Such research can help guide future nutrition education programming in Rwanda and other countries to make sure that families have the best available information to make appropriate dietary choices.

Of course, any program or intervention that involves working with animals must take into account the importance of food safety. For example, chickens can harbor contaminants such as E. coli. These added concerns and costs must be factored into the practical application of using animal-source foods for nutrition.

The evidence supporting the nutritional value of animal-source foods is not meant to downgrade the importance of consuming a diet that also consists of fruits, vegetables, and grains and avoiding highly processed foods rich in salt, fat, and sugar. But after nearly three decades researching nutrition solutions, I continue to be amazed by the powerful effect that animal-source foods appear to have on young children’s nutrition.

As a researcher, and as a mother, I plan to continue investigating this effect to help benefit those millions of children around the world who could be saved from the life-altering consequences of poor nutrition.