Grocery Assistance Program Study

Study Overview
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Brief Summary
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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
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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.

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

Conditions
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Food Assistance

Intervention / Treatment
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* Behavioral: F&V Bonus
* Behavioral: Restriction
* Behavioral: Bonus & Restriction


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control<br>Usual SNAP-like food benefits | |
| Experimental: Rewards<br>Usual SNAP-like food benefits, plus a modification to this food benefit program that entails a 30% bonus on eligible fruit and vegetable purchases (i.e. F&V bonus) | Behavioral: F&V Bonus<br>* 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<br>|
| Experimental: Restrictions<br>Usual SNAP-like food benefits, plus a modification that requires no sugar-sweetened beverages, candy, or sweet baked goods be purchased | Behavioral: Restriction<br>* 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<br>|
| Experimental: Rewards plus restrictions<br>Usual SNAP-like food benefits, plus two modifications to this food benefit program: one modification includes a 30% bonus on eligible fruit and vegetable purchases and the other modification is that sugar-sweetened beverages, candy, or sweet baked goods are not allowed to be purchased (i.e. Bonus & Restriction) | Behavioral: Bonus & Restriction<br>* 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<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Total Kilocalorie intake at 16 weeks | Evaluate 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. | 16 weeks | 
| Change from baseline in reported levels of household food security at 16 weeks | Assessing any change from baseline in the score of the The U.S. Household Food Security Survey Module: Six-Item Short Form | 16 weeks | 
| Change from baseline in Healthy Eating Index (HEI) Score at 16 weeks | Evaluate 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/ | 16 weeks | 
| Change from baseline in daily servings of fruits and vegetable (added together) at 16 weeks | Evaluate 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. | 16 weeks | 
| Change from baseline in daily total, in grams, of added sugars at 16 weeks | Evaluate 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. | 16 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Body Mass Index | Evaluate 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. | 16 weeks |