As the science linking nutrition and school performance grew stronger in the 1990s, school administrators began to reconsider the connection. Arkansas was the first to launch what became a massive experiment in school nutrition in 2003, requiring schools statewide to shape up nutrition and physical activity policies. Among the changes: no more soda and junk food in elementary school vending machines. Parents, however, were slow to improve meals in their own homes despite evidence that poor nutrition can impair children's ability to learn.
Hunger, whether caused by a skipped meal, an unbalanced meal, or chronic under-nourishment, interferes with concentration at school. The body can’t stockpile glucose, the main source of energy from food. Completely dependent upon glucose for energy, the brain is a powerhouse requiring consistent food intake to function properly. This makes the brain sensitive to variations in glucose levels, so just one skipped breakfast can reduce a child’s learning ability for morning lessons. In 1991, a study published in the "American Journal of Clinical Nutrition" revealed that even healthy, well-nourished children had trouble solving problems after skipping breakfast.
Nutrients in Food
An occasional feast on junk food is not likely to impair learning, but chronic poor nutrition might. Research on specifics of human nutrition and leaning is challenging, since it would be impossible and unethical to deprive children of vitamins in order to observe effects on learning. The influence of certain deficiencies is well established, however, such as iron deficiency, which can shorten a child’s attention span, alertness and ability to concentrate. For other nutrients, animal studies have shown clear links between malnutrition and cognitive impairment. In particular, Sasaki demonstrated that inadequate B-12 significantly impaired learning among laboratory rats.
Obesity stands as the most recently area of study regarding children and learning. Following up on Arkansas’ effort to curb obesity in schools, researchers at the Fay W. Boozeman College of Public Health noted that obesity can be correlated with poor academic performance. The researchers were quick to point out that psychological effects of weight-based teasing played a role in poor academic performance among overweight children.
Malnutrition can lead to health and physical problems even at the subclinical level. Children who are sick or in pain are not effective learners. Dr. Jim Raczynski, lead investigator for many of the Arkansas school, nutrition and obesity studies, argues that obesity is as likely a culprit in poor health as malnutrition.
"Childhood obesity increases the chances for significant childhood health problems as well as adult health problems," he said. " ... Parents should try to limit their children's access to unhealthy foods."