Gender Differences in the Relationship Between Long-Term Food Insecurity and Body Mass Index Among School Age Children

BACKGROUND:

Since economic recession in 2008, nearly 20 percent of households with children have experienced food-related hardships. Research has shown that food insecurity may disproportionately affect populations at highest risk for obesity. Given their detrimental health and developmental consequences among children, it is very important to understand the paradoxical relationship between food insecurity and obesity in childhood. Although growing body of research has investigated whether food insecurity contributes to increased weight gain over time, there is little consistency across studies. In particular, most of the works have relied primarily on cross-sectional data and longitudinal studies are needed to better understand the relationship between food insecurity and obesity in childhood.

Using the Early Childhood Longitudinal Study (ECLS-K), a nationally representative longitudinal study of school aged children, the study examines exposure to household food insecurity over a nine-year period and their relationships to children’s body mass index (BMI). In addition, this study examines whether the association between food insecurity and BMI differ by gender among children. 

METHODS:

This study uses four waves of data (grades kindergarten, 3, 5, and 8) from the ECLS-K. 5,913 children who have valid food security and BMI information were selected for the analyses.  Multiple categories for food insecurity were created to summarize food security status over the four waves, using the food security measure from the USDA 18-item standard US food-security scale. To characterize the persistence of food hardship, children were classified according to the number of years of household food hardship, ranging from 0 to 4. Children’s heights and weights were assessed directly in both kindergarten and 8^thgrade and BMIs were calculated from heights and weights.

A rich set of demographic (age, gender, race, disability status and birth weight), socioeconomic (poverty history and log mean income), parental (parent’s education, family type, and parental depression), and behavioral factors (hours watching TV, and number of exercise) were controlled. Mulivariate regression analyses were utilized for the study.

RESULTS:

Finding from multivariate analyses showed that that long-term patterns of food insecurity were positively associated with children’s BMI. Specifically, children from households that experienced transient food insecurity, including 2 years or 3 years of food insecurity, were more likely to have higher BMI at 8th grade, as compared to children from always food secure households. Also, persistent food insecurity during 9 years period was positively associated with BMI, though the association was not significant. In addition, subgroup analyses by gender indicated that the relationship between food insecurity and BMI were differentiated by gender. The findings showed that long-term exposure to food insecurity was associated with higher BMI for girls, whereas food insecurity was not linked to BMI for boys. This finding is consistent with evidence from previous research.

POLICY IMPLICATION:

The findings add to evidence that food insecurity is linked to higher BMI and obesity. Also, program and public policies to prevent childhood obesity may need to consider gender as a key risk factor. This research suggests that policy interventions alleviating household food insecurity may promote children’s physical development and well-being.