Skip to content

Grocery Assistance Program Study

Designing a Food Benefit Program to Optimize Diet Quality for Obesity Prevention

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02643576
Acronym
GAPS
Enrollment
296
Registered
2015-12-31
Start date
2013-04-30
Completion date
2016-03-31
Last updated
2017-10-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Food Assistance

Brief summary

This highly innovative experimental trial is designed to examine the independent and joint effects of prohibiting the use of SNAP-like benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more healthful foods.

Detailed description

More than 1 in 10 Americans participate in the Supplemental Nutrition Assistance Program (SNAP), a Federal food and nutrition program administered by the United States Department of Agriculture (USDA). SNAP, formerly known as the Food Stamp Program, provides funds to low-income families for the purchase of food. Benefits are provided on an electronic benefits transfer (EBT) card that is used like an debit card at stores. In recent years there has been growing recognition that SNAP participants are disproportionately obese, with poor diet contributing to this disparity. In response, there is great interest in considering ways in which SNAP may better meet its objective to help people and families buy the food they need for good health. Modifications to SNAP currently under evaluation involve offering incentives to encourage participants to purchase more nutritious food items. There is concern, however, that this strategy alone may be of limited usefulness in improving the nutritional quality of the diet for obesity prevention because incentivizing the purchase of more nutritious foods does not necessarily reduce the purchase of less nutritious foods (substitution effect may not occur) and may even increase the total calories purchased. An alternative strategy that has been extensively discussed by public health advocates and policy makers in recent years is prohibiting the purchase of less nutritious food items with SNAP benefits. Commonly consumed foods that are high in discretionary calories (defined as calories from solid fats, alcohol, and added sugars) are prime targets for exclusion because SNAP participants consume far more energy from discretionary calories (43%) than recommended. This strategy may be particularly effective if implemented in conjunction with incentives for the purchase of more nutritious foods. No studies have been conducted to evaluate whether prohibiting the purchase of foods high in discretionary calories with SNAP benefits may improve diet quality and reduce risk of obesity. Likewise research is lacking on the effect of effect of pairing restrictions with incentives. Thus, we propose to pilot a highly innovative experimental trial designed to examine the independent and joint effects of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more healthful foods. Key indicators of feasibility will include recruitment and retention (are targeted number of participants recruited and retained at a high rate?); fidelity of the intervention (are compliance measures successfully collected and do they indicate close compliance with experimental condition assignment?); and completeness of baseline and follow-up data. Using study data, analyses will be conducted to evaluate the independent and joint effects of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods.

Interventions

BEHAVIORALF&V Bonus

To examine the independent effect of offering an incentive (i.e. bonus dollars for fruit and vegetable purchases) to SNAP-like benefits to encourage the purchase of more healthful foods

BEHAVIORALRestriction

To examine the independent effect of prohibiting the use of SNAP-like benefits to purchase foods high in discretionary calories (i.e.sugar-sweetened beverages, candy, or sweet baked goods) on food purchases and diet quality

BEHAVIORALBonus & Restriction

To examine the joint effects of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more healthful foods

Sponsors

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
CollaboratorNIH
University of Minnesota
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* ≥ 18 years of age * Primary food shopper of household * Not currently participating in the Supplemental Nutrition Assistance Program (SNAP) * Not planning to apply for SNAP in the next 4 months * Able to read and write in English * ≤ 8 people living in household * Have a gross monthly income level that places the household at or below 200 percent of the Federal poverty level for their household size.

Exclusion criteria

* \< 18 years of age * Not primary food shopper of household * Currently participating in the Supplemental Nutrition Assistance Program (SNAP) * Planning to apply for SNAP in the next 4 months * Unable to read and write in English * \> 8 people living in household * Have a gross monthly income level that places the household above 200 percent of the Federal poverty level for their household size

Design outcomes

Primary

MeasureTime frameDescription
Change from baseline in Total Kilocalorie intake at 16 weeks16 weeksEvaluate the independent and joint effects on dietary intake of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods.
Change from baseline in reported levels of household food security at 16 weeks16 weeksAssessing any change from baseline in the score of the The U.S. Household Food Security Survey Module: Six-Item Short Form
Change from baseline in Healthy Eating Index (HEI) Score at 16 weeks16 weeksEvaluate the independent and joint effects on dietary intake of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods. More information about the HEI score can be found here: http://nccor.org/projects/hei/
Change from baseline in daily servings of fruits and vegetable (added together) at 16 weeks16 weeksEvaluate the independent and joint effects on dietary intake of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods. Servings of fruits and servings of vegetables are calculated from the output provided by NDS-R, which are based on the reported food intake as collected via 24-hour dietary recalls. Three recalls are collected at baseline and averaged; three recalls are collected at follow-up and averaged.
Change from baseline in daily total, in grams, of added sugars at 16 weeks16 weeksEvaluate the independent and joint effects on dietary intake of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods.

Secondary

MeasureTime frameDescription
Change from baseline in Body Mass Index16 weeksEvaluate the independent and joint effects on Body Mass Index of prohibiting the use of SNAP benefits to purchase foods high in discretionary calories and offering an incentive to encourage the purchase of more nutritious foods.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 1, 2026