Several studies addressing marginal food security, directly or indirectly, were reviewed. Although the research reviewed spanned a broad and heterogeneous spectrum, some core themes emerged. The clearest of those is that households with marginal food security are in important ways more like food-insecure households than food-secure households in socio-demographic characteristics, psychosocial profiles, and patterns of children’s developmental status and health risk. But evidence also emerged from the reviewed research and from the new research presented that marginal food security is not the same as food insecurity, as food insecurity is currently measured, and it probably would not be accurate or effective to combine marginally food-secure households with food-insecure households in estimating and reporting food security prevalence for the U.S. population. Although some of the research reviewed specifically recommended combining marginal food security with food insecurity, the results of the new research presented here argue against doing so. Results from that research provide strong support for separating marginal food security from both food security and food insecurity and treating it as a separate discreet category of its own.
The results of the new research support some but not all of our research hypotheses. We hypothesized that marginal food security would be positively associated with adverse health outcomes in both mothers and children, compared with similar food-secure dyads, and that the magnitude of observed associations between marginal food security and health outcomes would be intermediate between those observed with food security and food insecurity. This hypothesis was generally supported by the logistic regression models using a trichotomous food security status variable that isolated marginal food security from food security and food insecurity. In these models, marginal food security was positively associated with 4 of the 8 adverse child outcomes examined and negatively associated with one other child outcome (admit from ED), as was food insecurity, and the magnitudes of those associations were intermediate between those for food insecurity and food security as hypothesized. The negative associations with admit from ED seem paradoxical but may be a result of greater reliance on EDs for nonemergency care by food-insecure families with greater financial stress who are more likely to be uninsured, whereas food-secure families sought care in EDs more often for true emergencies.
Our hypothesis that associations between marginal food security and adverse child and caregiver health outcomes would reflect an ordinal dose-response–like effect, with marginal food security also posing a significant risk but acting similar to a lower “dose” of exposure to the risks posed by food insecurity, was supported by the research results but only partially confirmed. CIs for AORs representing associations of marginal food security and food insecurity with 4 of the 10 outcome measures did not overlap, indicating ordinal dose-response relationships for those 4 outcomes (child and caregiver fair/poor health, PEDS1 developmental risk, and caregiver depressive symptoms) ().
This work elucidates how marginal food security should be treated relative to the categories of food security and insecurity in estimating prevalence of exposure to lack of enough food but produced some unexpected results. In the 2 sets of logistic regression models using dichotomous food security predictors, with marginal food security combined first with food security then with food insecurity, there were no apparent significant differences in magnitude of associations of food insecurity with the child health outcomes between the 2 forms of the food security predictor, but effect size was attenuated (). Thus, from the purely statistical perspective of estimated associations between food insecurity and child health and developmental risk outcomes, these results suggest that it may not matter much whether marginal food security is combined with food security or insecurity. However, the results have some troubling clinical and public health implications. The AORs for associations between food insecurity and the child health outcomes that were significant are generally larger when marginal food security is combined with food security in the usual way, but their CIs all overlapped with those for the smaller AORs for the other form of the predictor (). Yet considering marginal food security as part of food security can lead to a smaller proportion of the population of young children being identified as at risk for inadequate nutrition (, column headings).
The same was not the case, however, for the 2 caregiver outcomes. The AORs for associations of food insecurity with both caregiver depressive symptoms and fair/poor health were greater when marginal food security was combined with food security in the usual fashion than with marginal food security combined with food insecurity, and the CIs for the 2 sets of AORs did not overlap. This strongly suggests that the associations of food insecurity with the odds of caregiver depressive symptoms and fair/poor health are significantly greater when food insecurity is defined in the usual way (). That result argues against combining marginal food security with food insecurity, because doing so could lead to an underestimation of the associations between food insecurity and these 2 maternal health outcomes.
Several limitations should be considered when interpreting these results. The cross-sectional design precludes the determination of cause-effect relationships. Though we controlled for important confounding variables, other unmeasured confounders may exist. Despite the use of questions independently validated by other researchers or by the current research group in earlier subsamples whenever possible, respondents may have over- or under-reported negative child outcomes. Because this study assesses low-income families in emergency rooms and hospital-based clinics, their children are already at elevated risk for developmental and health concerns and may not be representative of all low-income children. However, we excluded urgently ill or injured children, so some of the highest-risk children were not included, which also may help explain the paradoxical relationship with admission on the day of the ED visit. Excluding these families may contribute to underestimating the impacts of marginal food security.