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 participation in the program.

中文翻译：

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不健康饮食行为与参与补充营养援助计划 (SNAP) 之间的关联：没有证据支持自我选择假说

与符合资格的非参与者相比，补充营养援助计划 (SNAP) 参与者的饮食消费往往不健康。有人建议，尽管从未经过实证检验，参加 SNAP 的个人在参与计划之前可能有不健康的饮食习惯。我们采用纵向队列研究设计，研究了低收入成年人的 SNAP 参与状况与先前饮食行为之间的关联，以检验饮食消费不健康的个体自我选择加入 SNAP 的论点。在基线 (T1) 和 2-4 年后 (T2) 对主要来自低收入城市的家庭样本进行了调查。主要分析仅限于 T1 时未参加 SNAP 且 T1 和 T2 时家庭收入均低于联邦贫困线 (n = 170) 200% 的成年人。根据 T2 中 SNAP 参与情况，参与者被分为两类； (a) 非参与者 (n = 132)：在 T1 或 T2 不参与 SNAP，以及 (b) T2 SNAP 参与者 (n = 38)：在 T2 参与 SNAP，但不参与 T1。通过自我报告测量整个水果、果汁、蔬菜、含糖饮料（SSB）和能量密集型零食的每日消费频率。为了观察参加 SNAP 之前两组之间的饮食差异，比较了 T1 行为。非参与者和 T2 参与者在 T1（参与 SNAP 之前）的饮食行为没有显着差异，这表明我们的研究样本中没有证据表明饮食不健康的个体自我选择加入 SNAP。关注鼓励健康饮食习惯参与该计划的政策变化可能会有益于 SNAP 参与者饮食的改善。