The association between unhealthy dietary behaviors and participation in the Supplemental Nutrition Assistance Program (SNAP): No evidence in support of the self-selection hypothesis

Supplemental Nutrition Assistance Program (SNAP) participants tend to have unhealthier dietary consumption compared to eligible non-participants. It has been suggested, though never empirically tested, that individuals who enroll in SNAP may have unhealthy diets prior to program participation. Using a longitudinal cohort study design, we examined the association between low-income adults' SNAP participation status and prior dietary behaviors to test the argument that individuals with unhealthier dietary consumption self-select into SNAP. A sample of households from predominantly lower-income cities were surveyed at baseline (T1) and 2-4 years later (T2). The main analyses were restricted to adults who did not participate in SNAP at T1 and with household income <200% of the federal poverty line (n = 170) at both T1 and T2. Participants were grouped into two categories, based on their SNAP participation at T2; (a) Non-participants (n = 132): no SNAP participation at T1 or T2, and (b) T2 SNAP participants (n = 38): SNAP participation at T2 but not T1. Daily consumption frequency of whole fruits, fruit juice, vegetables, sugar-sweetened beverages (SSBs), and energy dense snacks were measured through self-reports. To observe dietary differences between the two groups prior to SNAP participation, T1 behaviors were compared. There were no significant differences in dietary behaviors at T1 (prior to SNAP participation) between non-participants and T2 participants, providing no evidence of self-selection of individuals with unhealthier dietary consumption into SNAP among our study sample. Improvements in SNAP participants' diets may benefit from focusing on policy changes that encourage healthy dietary habits during participation in the program.