Even before a child is born, nutrition plays a critical role in her development. Neurologist Lise Eliot reports in her book "What's Going On In There?" that mothers who do not get sufficient protein during pregnancy sometimes give birth to children with slowed brain development. A 2011 study published in "Nutrition Reviews" found that deficits in polyunsaturated fatty acids could slow down brain development and was particularly likely to affect spatial reasoning -- a skill that plays an important role in a child's ability to master math and science. Children whose mothers were chronically malnourished during pregnancy may continue to struggle when they begin school, particularly if they did not get good nutrition in infancy.
Children who get inadequate nutrition often struggle to pay attention and, when they do focus, have shorter attention spans than children who get sufficient nutrition, according to the United Nations. Attention plays a major role in learning because children who can't focus are unlikely to be able to master even basic lessons. Kids who can't pay attention can also end up being a distraction to other children, according to the textbook "Child Psychology," which means that the effects of poor nutrition can spread beyond a single malnourished child.
A 2002 University of Montana research report emphasized the correlation between poor nutrition and learning disabilities. Poor nutrition can worsen the effects of a learning disability, and some children may develop learning disorders due to poor nutrition. These disorders can interfere with a child's ability to learn, make certain domains of knowledge -- such as reading or math -- more challenging or slow down a child's brain development.
According to The World Bank, poor nutrition can lower children's IQs, and some malnourished children may suffer an IQ drop of 15 points or more. Poor nutrition also interferes with behavioral development and can cause children to hit developmental milestones later than average, causing them to learn more slowly and fall behind their peers. The World Bank further emphasizes that providing adequate nutrition to undernourished children can reverse some of the negative cognitive effects of poor nutrition.