SNAP: Summary of Science

The Supplemental Nutrition Assistance Program (SNAP) is the nation's largest federal nutrition assistance initiative, aimed at reducing hunger and improving food security by increasing the purchasing power of low-income individuals and families. Although SNAP is not intended to serve as a dietary health intervention for chronic disease, it plays a vital role in helping participants meet their basic nutritional needs. The program enhances access to food by enabling purchases at retailers that accept Electronic Benefit Transfer (EBT) cards and by providing consistent financial support. As an anti-hunger income support program, SNAP also promotes household stability by adjusting benefits to reflect changing individual or family circumstances. SNAP is a cost-effective program that can reduce health care spending by up to $1400 per year among low-income adults in the United States. SNAP upholds the dignity, autonomy and personal choice of participants, empowering them to decide how best to nourish themselves and their families.

SNAP supports vulnerable populations including children, older adults and people with disabilities and helps stimulate local economies. Eligibility is primarily based on income, with gross income below 130% and net income below 100% of the federal poverty level). Able-bodied adults aged 18–52 without dependents (ABAWDs) must meet specific work requirements unless exempt. Additional eligibility limits apply to household resources, student status, with most full-time college students ineligible unless they meet certain exemptions.

Proposed Revisions

Recent federal proposals seek to reduce program costs and tighten SNAP eligibility by expanding work requirements, including:

• Raising the age limit for able-bodied adults without dependents (ABAWDs) subject to work rules from 54 to 64, and requiring parents of children over age 6 to comply with work requirements.
• Proposed changes would also limit states' ability to waive time limits in areas of high unemployment, restricting waivers to only those regions with very high unemployment, and would prohibit states from grouping regions together to meet the criteria.
• Additional proposals aim to shift more administrative and financial responsibility to states, cap benefit increases to the rate of inflation, and reduce deductions for utility expenses.
• Another proposal would allow states to request USDA waivers to restrict the types of foods that can be purchased with SNAP benefits, such as sugary beverages and candy.
  • Some states including Indiana (soft drinks and candy), Iowa (taxable food items), and Nebraska (soda and energy drinks) already have waivers approved to implement such restrictions.

Understanding SNAP and WIC

SNAP and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) are federal nutrition programs that have income eligibility requirements. However, they serve distinct populations and purposes.

SNAP provides monthly benefits to low-income individuals and families of all ages, allowing recipients to purchase most food items based on personal preferences.

• As an entitlement program, SNAP is guaranteed federal funding to meet the needs of all eligible participants.

WIC supports low-income pregnant, postpartum and breastfeeding women, as well as infants and children under five who are at nutritional risk. WIC offers a prescribed package of nutrient-rich foods, along with nutrition education, breastfeeding support, and referrals to health care services.

• WIC mandates a health or nutrition risk assessment.
• WIC, is a discretionary program subject to annual appropriations by Congress, which can result in funding shortfalls that may limit participation or reduce benefits.

Summary of Evidence Evaluating SNAP

Benefit of SNAP

Food Security

SNAP plays a critical role in reducing food insecurity among low-income household. Evidence indicates that SNAP lowers the risk of very low food security by approximately 20%, providing an essential safety-net for low-income households, especially since few participants also receive cash assistance, with only about 4% of childless households and 10% of those with children receiving such support. A 2025 review found that increasing benefits for food assistance programs like SNAP shows strong potential for improving food security, with consistent evidence from high-quality studies on Summer EBT and some support from lower-quality SNAP studies.

Diet Quality

Despite SNAP's benefits in alleviating food insecurity, challenges remain regarding diet quality among participants. A survey found that SNAP participants showed less improvement in diet quality compared to low-income nonparticipants. Diet disparities remained or worsened for several key food groups, such as processed meats and added sugars. Overall, SNAP participants were more likely to have poor diet quality and less likely to achieve intermediate or ideal scores compared to others. A 2015 systematic review reported that SNAP participants had similar overall nutrient intake compared to income-eligible nonparticipants, but adult participants had lower dietary quality. Children's diets and sugar-sweetened beverage consumption were generally similar between the two low-income groups.

A 2020 secondary analysis explored how SNAP participation relates to the nutritional quality of at-home food purchases among low-income households, while also considering differences based on nutrition attitudes. Using data from USDA's FoodAPS, the analysis included SNAP participants and eligible nonparticipants, with results showing that people receiving SNAP who were nutrition-oriented had significantly better quality of dietary patterns, per the Healthy Eating Index, than those who were not nutrition oriented. This suggests that restricting SNAP purchases of unhealthy foods may improve diets among less nutrition-focused households but would likely have little impact on those already making healthy choices.

Together, these findings highlight SNAP's crucial role in reducing food insecurity while underscoring the need for targeted strategies to improve diet quality among participants. Future policy efforts should balance maintaining food access with promoting healthier dietary choices to maximize SNAP's overall impact on nutrition and health.

Evidence on Incentives and Restrictions

Food Security

Policies incorporating incentives and restrictions within food assistance programs aim to improve both diet quality and food security among low-income populations. A 2016 study evaluated a proposed food assistance policy that incentivized fruit and vegetable purchases and restricted less nutritious foods among low-income individuals not enrolled in SNAP. Participants were randomly assigned to one of four groups: incentive only; restriction only; both incentive and restriction; or control (no incentive or restriction). All groups saw reductions in household food insecurity, but the decrease was significantly smaller in the control group compared to the intervention groups.

Building on this, a 2024 study tested whether restricting purchases of sugary foods with or without added fruit and vegetable incentives improved nutrition among low-income families. Participants were randomized to: restriction only (no sugary beverages, baked goods, or candy); restriction plus a 30% fruit and vegetable incentive; or control (no incentives or restrictions). While household food security improved across all groups, including reductions in child food insecurity, the differences between the intervention and control groups were not statistically significant.

A 2020 study was conducted to understand the perspectives of those participating in SNAP interventions about proposed restrictions and incentives. Results from this study indicated no differences in buying enough food for the household and no difference in program satisfaction. Overall, the majority of SNAP supports inclusion of financial incentives for produce purchases, and a modest majority of them are receptive to restrictions on purchasing foods high in added sugars.

Diet Quality

Research examining the effects of policies targeting food-based incentives and restrictions within SNAP on diet quality among low-income populations has produced mixed but insightful findings. In 2024, a systematic review was undertaken of seven studies, four randomized controlled trials (RCTs) and three simulation studies focused on restricting SSB purchases within SNAP. Among the RCTs, three showed statistically significant reductions in SSB purchases or consumption, although one reported only a minimal, non-meaningful change. All three simulation studies predicted significant decreases in SSB intake when purchase restrictions were applied.

Results from the previously mentioned 2016 study evaluating incentives and restrictions within SNAP found that those in the combined incentive-plus-restriction group achieved greater dietary improvements such as lower energy intake and higher Healthy Eating Index (HEI) scores compared to controls. The restriction-only group also experienced reduced energy intake relative to controls.

A 2024 study investigated the effects of incentives and restrictions on food purchases and intake. While these approaches reduced sugary food purchases and incentives with restrictions tended to improve diet quality, these improvements were not statistically significant. Within-group improvements in diet quality (HEI-2015 scores), energy intake, and body mass index (BMI) were observed across adults and children in all study arms, but differences between groups remained non-significant. Sensitivity analyses supported the consistency of these findings.

Differences between these studies may help explain the varying results. The 2024 study enrolled individuals who met SNAP eligibility but were not participating, enhancing its external validity for actual SNAP participants; the 2016 study included near-eligible non-participants. Furthermore, the 2024 trial used state-based food benefit amounts that more accurately reflected SNAP benefits, compared to average amounts in the 2016 trial. However, the 2024 study experienced higher attrition (20% vs. 5%) and more non-compliance-related discontinuations (16% vs. 3%), which may have impacted internal validity.

A 2018 study compared SNAP participants, income-eligible non-participants and income-ineligible non-participants, finding no significant differences between groups in reductions of sugar-sweetened beverage (SSB) intake.20 Nevertheless, within-group decreases in added sugars and SSB consumption were noted among income-ineligible non-participants and SNAP participants.

In 2018, a study evaluated the overall and comparative impacts and cost-effectiveness of food incentives, disincentives, and restrictions in SNAP for health outcomes using nationally representative data and a validated microsimulation model. This study assessed three SNAP policy options: (1) a 30% subsidy for fruits and vegetables; (2) the same subsidy combined with a ban on sugary drinks; and (3) a broader "SNAP-plus" approach offering a 30% subsidy for healthy foods and a 30% disincentive for unhealthy items like sugary drinks, junk food, and processed meats. The results from this study showed that SNAP-plus policy which consists of healthy incentives and unhealthy disincentives, provided the largest benefits in health and health care savings.

Taken together, these studies highlight the complexities of influencing dietary behaviors through policy measures in low-income populations, suggesting that while restrictions and incentives show promise, additional research is needed to clarify their long-term impact on diet quality and health outcomes.

Summary of Evidence Evaluating SNAP-Ed

SNAP-Ed, formally known as the National Education and Obesity Prevention Grant Program, is a cost-effective strategy that delivers nutrition education grounded in scientific evidence. The program collaborates with state and local organizations to support communities through various initiatives, such as nutrition education sessions, social media outreach and strategies to enhance community policies, systems, and environments. It plays a vital role in promoting food and nutrition security in underserved areas nationwide.

According to a 2024 multi-state outcome report, 23 states provide SNAP-Ed programming at more than 17,300 sites, reaching 1,275,155 people and specifically at least 905,988 youth through direct education. Data from these states shows reductions in food insecurity and improvement in nutrition and physical activity behaviors. SNAP-Ed equips individuals with practical skills and supports community-driven changes.

Evidence from the literature also supports SNAP-Ed's effectiveness. A 2019 narrative review of 14 studies found that SNAP-Ed interventions statistically improved food security in the three studies that reported this outcome. Ten studies reported that SNAP-Ed interventions had mixed results on dietary intake and diet quality outcomes. Heterogeneity in tools for assessment of dietary intake and diet quality as well study designs might have contributed to these mixed results.

A 2023 quasi-experimental study of two groups indicated that the intervention group (SNAP-Ed nutrition and physical activity education) reported a significantly higher increase in fruit consumption – this was primarily due to a greater rise in the intake of 100% fruit juice. The intervention students also showed a significantly greater increase in total vegetable intake, starchy vegetables, salad/greens and beans (0.04 vs. −0.03; P = 0.025). No differences in pre-post physical activity outcomes were reported.

A 2020 cross-sectional study showed that SNAP-Ed physical activity programs showed improved cardiorespiratory fitness and slightly lower BMI z-scores compared to those in similar schools without such programs.

Conclusion

Current scientific evidence supports SNAP's crucial role in reducing food insecurity, but its relationship with diet quality is complex. There has been some research to evaluate the effectiveness of policies focusing on incentives and restrictions on food purchasing or dietary behaviors. Modeling studies have indicated that targeted restrictions particularly on sugar-sweetened beverages can improve dietary quality and reduce chronic disease risk. On the other hand, some experts caution against such measures, citing limited evidence, potential stigma and concerns over participant autonomy.

Current limited evidence suggests that combining incentive-based strategies, such as subsidies for fruits and vegetables, with targeted restrictions on unhealthy foods like sugar sweetened beverages and junk food may promote healthier choices without limiting freedom. These differing perspectives underscore a central policy challenge: how to effectively improve nutrition outcomes among SNAP participants while maintaining dignity, equity, and choice.

Moving forward, a balanced approach guided by rigorous evidence and informed by the lived experiences of program participants will be essential to designing sustainable and inclusive solutions.

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References

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