New Study Reports Strong Links Between Food Insecurity and Negative Developmental Consequences for Young School-age Children

Abstract: Food Insecurity Affects School Children’s Academic Performance, Weight Gain, and Social Skills by Diana Jyoti, Edward A. Frongillo, and Sonya J. Jones, published in Journal of Nutrition, December 2005. (Full document requires subscription.)

Overview. A recently published article in the Journal of Nutrition by researchers from Cornell University and the University of South Carolina reports strong links between food insecurity and negative developmental consequences in young school-age children (kindergarten to third grade), including consequences for social skills and behavior, reading performance, mathematical skills, and weight gain. The authors of the study conclude: “Overall, this study provides the strongest empirical evidence to date that food insecurity is linked to developmental consequences for girls and boys, particularly impaired social skills development and reading performance for girls… [T]he most plausible interpretation of the results is that food insecurity in the early elementary years has developmental consequences. Furthermore, these consequences may be both nutritional and nonnutritional.”

How the study was done. The researchers analyzed data from a nationally representative study called the Early Childhood Longitudinal Study—Kindergarten Cohort. The study sample consisted of 21,260 children, in 1592 elementary schools, who attended kindergarten in 1998-1999 and were followed up to the third grade. Because this data set is longitudinal (i.e., following children’s development over several years), it allowed the researchers to analyze the effects of food insecurity over time, which seldom is found in the current scientific literature. The researchers also used this data set because it is a large sample, which provides greater statistical power; it is nationally representative, which allows generalization of results to the entire early elementary population; and it contains a great deal of additional information about the children, parents, and households. The researchers used: data on food insecurity based on the USDA food security module; direct academic assessments of mathematical and reading ability; measured weights, heights and resulting BMIs; and evaluations of students’ social skills and behaviors from teacher questionnaires.

What the researchers found. Overall, the researchers report that the results of their analysis of this nationally representative data set demonstrate that food insecurity affects children’s academic performance in reading and math, weight gain, and social skills. They studied these effects in different ways. When they compared food insecure kindergarteners to food secure kindergarteners, they found that the food insecure children (both boys and girls) had smaller increases in math scores and reading scores over time. Food insecure girls showed greater gains in weight and BMI than food secure girls, and food insecure boys showed greater declines in social skills than food secure boys. The researchers conclude from these results: “Food insecurity thus serves as an important marker for identifying children with delayed trajectories of development.”

When the researchers looked at change over time, from kindergarten to third grade, they found that children from households that became food insecure (i.e., they were food secure in kindergarten but became food insecure by third grade)–whether they were compared with persistently food secure households or households that became food secure–showed poorer reading performance, especially among girls. They also found that there was a fairly short lag time between food insecurity and its effects on girls’ reading. Persistent food insecurity through the third grade increased the delay in reading compared to the effect of food insecurity in kindergarten alone, and the association between food insecurity with reading performance in kindergarten was reversed if the household was no longer food insecure by third grade. The researchers conclude: “…this study advances the field by providing the strongest longitudinal evidence that food insecurity is associated with impaired reading performance in girls.” (The effect of food insecurity at kindergarten, not the change over time, best predicted math performance. The researchers speculate that this is because it takes longer for food insecurity to affect math performance.)

According to the authors, “This is the first study to investigate the longitudinal relationship between household food insecurity and social skills in children.” When looking at change in social skills over time, they found that the time lag between becoming food insecure and smaller gains in social skills was relatively short for girls. If girls became food secure by third grade, the negative effect of food insecurity in kindergarten on social skills was reduced. Also, girls from households that became food insecure between kindergarten and third grade showed smaller gains in social skills compared to either households becoming food secure or persistently food secure households.

Why is there a relationship between food insecurity and developmental outcomes? The authors discuss two possible mechanisms for this relationship. One is that food insecurity results in compromised dietary quality and quantity, both of which can negatively affect child development. The other is that food insecurity may act as a psychological or emotional stressor, affecting parent and child behavior. For example, it has been shown that low socioeconomic status in children is associated with significantly higher cortisol levels, which are in turn associated with depression, cognitive effects, and atrophy of brain structures involved in learning and memory. Also, research has demonstrated a relationship between economic hardship and increased social behavior problems in children.

What are the implications of the study findings? Because of the statistical power, generalizability and longitudinal nature of the data, this paper is a strong confirmation of the negative consequences of household food insecurity for early elementary age children. Furthermore, the paper demonstrates that food insecurity influences abilities that impact future academic and life success—reading, math, and social skills. Thus, this study reaffirms the deep concerns expressed by many nutritionists, advocates and health professionals about the negative effects of household food insecurity on children and the urgency of ending this problem.