Increasing obesity epidemic among children is a prominent social problem and an important policy concern in the United States. Given the detrimental health and developmental consequences of childhood obesity, it is very important to understand determinants of obesity among children. Growing body of research has investigated whether food insecurity contributes to the obesity in children. Much of the work is cross-sectional, however, and findings remain inconsistent. More research is needed to understand the paradoxical relationship between food insecurity and childhood obesity. Using longitudinal approach, the study examines exposure to household food insecurity over a nine-year period and the relationships between that exposure and children body mass index (BMI) and obesity.

METHODS:

Data were obtained from four waves (kindergarten, 3rd, 5th, and 8th grades) of the Early Childhood Longitudinal Study—Kindergarten Cohort (ECLS-K), a study that followed a nationally representative sample of students from kindergarten entry in 1998-1999 through eighth grade. Children’s heights and weights were assessed directly in both kindergarten and 8^thgrade and BMIs were calculated from heights and weights. Multiple categories for food insecurity were created to summarize food security status over the four waves, using the food security measure from the United States Department of Agriculture (USDA) 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. A rich set of confounding factors, including economic resources, child characteristics, parental, household, and contextual characteristics, are controlled. A lagged dependent variable model using ordinary least squares (OLS) regression is utilized for the study.

RESULTS:

Descriptive statistics suggest that food insecurity over time tends to be transient rather than persistent conditions. Single-year estimates substantially underestimate the share of children whose households experienced food hardships at some point during their childhood years. Preliminary multivariate analyses indicated 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.

POLICY IMPLICATION:

The findings add to evidence that food insecurity is linked to higher BMI and obesity. This research suggests that policy interventions alleviating household food insecurity may promote children’s physical development and well-being.