Change in food security status and change in weight are not associated in urban women with preschool children.

Cross-sectional studies have suggested that food insecurity leads to obesity in women. The objective of this longitudinal study was to determine whether changes in women's food security status were associated with changes in their body weight. In 20 large U.S. cities, 1707 mothers of preschool children were followed for 2 y. At baseline (2001-2003) and follow-up (2003-2005), women's height and weight were measured and food security status was assessed with the US Household Food Security Survey Module. Those with no positive responses on the food security items were considered fully food secure and those with any positive responses were considered not fully food secure. Seventy-one percent were unmarried and 45% had incomes below the U.S. poverty threshold. At baseline, 41% were obese (BMI > or = 30 kg/m(2)) and 31% were not food secure. After adjusting for sociodemographic characteristics and baseline BMI, there were no significant differences in 2-y weight increases between 4 groups that differed in food security status: food secure at both time points (n = 1000), 1.7 kg (95% CI = 1.1-2.3); food secure at baseline, but not at follow-up (n = 183), 2.1 kg (95% CI = 0.7-3.5); not food secure at either time point (n = 257), 1.7 kg (95% CI = 0.5-2.9); and not food secure at baseline but food secure at follow-up (n = 267), 1.9 kg (95% CI = 0.7-3.0). In this population of urban women, changes in food security status over 2 y were not significantly associated with changes in weight. These findings do not support a causal association between food insecurity and obesity.