Proposals that directly or indirectly link program participation to unhealthy childhood weight persist without consistent research evidence. Studies that relate SNAP to obesity have been vulnerable to selection bias, specifically to the possibility that families who participate in SNAP may differ from those who are eligible, but non-participating, in unobservable ways that are mistaken for program participation effects.In this study, we aimed to disentangle SNAP participation effects from the effects of other experiences and conditions in childhood, in part by attending to the places in which children live.
Methods. Using distinct periods of childhood (2-8; 9-13; 14-18), we examined whether SNAP participation in the context of varying neighborhood conditions was associated with the time children spent obese. The sample comprised children, observed from 1986-2012, from the Child and Young Adult sample of the National Longitudinal Survey of Youth, whose mothers had participated in the 1979 NLSY. We compared results from several modeling strategies: OLS regression with the full sample, OLS regression with the siblings-only sample, and sibling-fixed-effects (FE) regressions. The focal comparison was between the proportion of time spent using only SNAP and the proportion of time spent in poverty, with neither SNAP nor TANF participation.
Results. We found that children living in more advantaged neighborhoods spent less time obese during childhood, although this relationship was largest for young children aged 2-8 and older children aged 14-18, with more pronounced effects illustrated in the FE models, relative to the OLS models. Of most relevance to the central study question, time participating in SNAP during ages 2-8 and ages 14-18 was associated with less time spent obese, to an increasing degree as the level of neighborhood advantage declined. In light of our additional finding that most who spend an extended period of time using SNAP live in the least advantaged neighborhoods, these results suggest that SNAP participation during these childhood years may help to reduce time spent obese as a child.
Conclusions and Implications. Results of this investigation suggest that participation in SNAP may have protective effects for children spending time in low-income households within less advantaged neighborhoods. Whether this effect operates through the channels of food type, food quality, stability of food access, or some other mechanism remains unclear. However, evidence for the protective role that may be played by SNAP as isshould be weighted in considerations of proposals to change access to SNAP or conditions of its receipt.