Including a few bites of meat in the diets of poor children from developing countries improves both their health and their performance in mental tests, according to reports presented at this year’s annual meeting of the American Association for the Advancement of Science.

In one study from rural Kenya, investigators found that children who ate 2 ounces of meat every day, along with their usual lunch of corn and beans, performed better in problem-solving tests than children given supplements of milk or vegetable oils.

This small amount of meat gave children all their daily needs for vitamin B12, 68 percent of all they needed of zinc, and 26 percent of their daily iron requirements, the researchers note.

Dr. Howarth Bouis of the International Food Policy Research Institute in Washington, DC, told Reuters Health that research shows that children who don’t get enough iron, zinc and other nutrients have a weakened immune system, along with growth and cognitive impairments.

And when entire generations of children aren’t getting enough nutrients, that can have implications nationwide, Bouis added. For instance, the World Bank estimates that micronutrient deficiencies cost South Asia 5 percent of its GDP each year, he said. “When you can’t work as hard, you can’t think as well…it takes away from economic development,” Bouis said.

He added that children in developing countries don’t get enough nutrients because they can’t afford them, so it’s up to the government to intervene. For instance, the government could implement programs that increase production of nutrient-rich foods, which drives down the price, Bouis suggested.

He noted that the purpose of the presentation was to help the world recognize the seriousness of the problem. Adding nutrients to kids’ diets “would do a lot of good,” he said.

As part of the presentation, Bouis - who also holds a position at the International Center for Tropical Agriculture in Columbia - discussed the benefits of selectively breeding crops to create strains that are high in iron and other nutrients.

Programs that boost the supply of animal products and nutrient-rich plants become sustainable solutions to nutrition problems in childhood, he reasoned, while giving kids supplements is just a quick fix that constantly needs to be repeated.

During the two-year Kenya study, investigators gave several hundred children a usual lunch of corn and beans, but also added either 2 ounces of meat, milk or the same number of calories in vegetable oil.

They found that children given any supplementary foods gained more weight than other children, and also increased their upper arm muscle mass. Children who ate meat received significantly higher scores on problem solving tests.

Children given either meat or milk also took in significantly more vitamin B12. Indeed, after the study, only 10 percent of children given supplements had B12 deficiencies, while nearly half of untreated children still showed B12 deficiencies, the authors note.

These findings match the results from previous studies from Egypt and Mexico, they note, in which investigators found that dietary changes can make a big difference to children.