Background: Food insecurity is the state of being without reliable access to enough food for an active, healthy life. While the relationship between food insecurity and weight gain has been inconsistent in children and men, food insecurity is consistently associated with chronic distress and higher weight status among women. The primary goal of this dissertation is to assess the associations between food insecurity and weight gain and obesity in low income Latino children, and food insecurity and unhealthy weight gain among a California representative sample of pregnant women. Seventeen percent of American children are obese, making childhood obesity one of the most prevalent health challenges American children face. Forty-eight percent of women in America gain weight in excess of the Institute of Medicine’s (IOM) gestational weight gain guidelines; over 56% of obese women and 51% of white women gain in excess of the IOM guidelines, making these groups especially vulnerable. Three studies have found evidence that obesity may stem from early life exposure to food insecurity, although no study has examined if early exposure to food insecurity is associated with obesity in late childhood and early adolescence. Only one study has assessed if transitioning to and from food insecurity is associated with growth in children and they found that changing food security status may affect boys and girls differently. Additionally, only three studies have assessed the association between food insecurity and gestational weight gain among pregnant women and they have found positive and null associations. Identifying if there is an association between food insecurity and weight status among low income Latino children and pregnant women would inform programs such as the Special Supplemental Nutrition Program for Women, Infants, and Children that aim to alleviate food insecurity and promote healthy weight gain in these vulnerable populations.
Methods: The Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study collected information from Latino mother-child dyads from pregnancy to age 12. The first paper in this dissertation analyzes 243 mother-child dyads from CHAMACOS to assess longitudinal associations between exposure to food insecurity in the first years of life and changes in growth and obesity status from age 2 to 12 by implementing linear and logistic regression models. The second paper analyzes 204 children from CHAMACOS, and investigates the longitudinal associations between food security status, changing food security status, and persistency of food insecurity with changes in growth and obesity status by implementing generalized estimating equations. The third paper applies linear and multinomial logistic regression models to investigate the cross sectional association between food insecurity and gestational weight gain among 12,097 women from California’s Maternal Infant Health Assessment (MIHA), a random sample survey of English- or Spanish-speaking women in California who recently had a live birth.
Conclusion: Early life exposure to food insecurity in the first two years of life was associated with growth in childhood differentially between boys and girls at different times, even up to ten years after the food insecurity was experienced. Household food insecurity was associated with decreased growth in childhood and transitioning to and from food insecurity was also negatively associated with growth. During pregnancy, food insecurity was significantly associated with increases in gestational weight gain among non-Hispanic African American women. However, these changes in weight status did not translate into changes in obesity status or gaining excessive weight during pregnancy according to the IOM gestational weight gain guidelines. The associations between food insecurity and growth in children were modified by age and gender while the associations between food insecurity and gestational weight gain were modified by race/ethnicity. Of the few studies that have previously examined the relationships between food insecurity and weight status among Latino children and pregnant women, very few tested for effect modification by age, sex, and race/ethnicity. Therefore more studies that consider differential influences of food insecurity on weight are needed before we can conclude food insecurity is not associated with obesity or excessive gestational weight gain in these vulnerable populations.
